Davias and Harris are wowing them again this week at the Geological Society of America. I will try and get a hold of their wonderful presentation and post…..
Posted!: [wonderplugin_pdf src=”https://cosmictusk.com/wp-content/uploads/3-1_Davias_linked.pdf” save=”1″]
A TALE OF TWO CRATERS: CORIOLIS-AWARE TRAJECTORY ANALYSIS CORRELATES TWO PLEISTOCENE IMPACT STREWN FIELDS AND GIVES MICHIGAN A THUMB
Pleistocene Epoch cosmic impacts have been implicated in the geomorphology of two enigmatic events. Remarkably, in both cases spirited debates remain unsettled after nearly 100 years of extensive research. Consensus opinion holds that the Australasian (AA) tektites are of terrestrial origin despite the failure to locate the putative crater, while a cosmic link to the Carolina bays is considered soundly falsified by the very same lack of a crater.Likely >100 km in diameter, these impacts during geologically recent times should be readily detectable on the Earth’s surface. The improbability that two craters have eluded detection informs a hypothesis that a single impact at ~786 ka generated AA tektites as distal ejecta and Carolina bays as progeny of proximal ejecta. The AA astroblem search is focused on SE Asia despite a strewn field encompassing >30% of the Earth’s surface. This spatial scope implies to us that interhemispheric transits should be considered, as does findings that AA tektites were solidified in a vacuum, then ablated on re-entry at ~10 km sec-1. A Coriolis-aware triangulation network operating on the orientations of 44,000 Carolina bays indicates a focus near 43ºN, 84ºW. Referencing the work of Urey and Lin, we propose that a near-tangential strike to the Earth’s limb generated the 150 x 300 km oval depression that excises Saginaw Bay and opens Michigan’s Thumb. That region was likely buried under deep MIS 19 Laurentide ice at 786 ka. Schultz has shown that oblique impacts into continental ice sheets yield non-traditional astroblems, and multiple glaciations have since reworked this site, making identification more challenging. Hypervelocity gun tests show that oblique impacts produce a vertical plume of ejecta, biased slightly down-range. Ballistic trajectories reflecting such a plume deliver tektites to all AA finds when lofted at ~10 km sec-1 and parameterized with the proposed depression’s location and 222º azimuth. Chemical and isotopic characteristics of AA tektites suggest they were sourced from sandstone and greywacke of Mesozoic age, which is congruent with Michigan Basin strata lost when The Thumb developed. The distribution of proximal ejecta may explain anomalous pulses of regolith in moraines and sediment loading in regional drainage basins recently dated ~800 ka using 10Be/26Al methods.
George, Wow.
So Davias is putting the formation of the Carolina Bays at >780ka.
And that it was the same object that formed the AA tektites?
Wow, I had no idea that the composition of the AA tektites was. traced to NA.
Fascinating, the low impact angle magnifies the “splash” effect and carries ejecta downrange.
And I belive it’s Schultz that postulated this is what happens at chixilub,
Fascinating stuff.
Aboriginal legends reveal ancient secrets to science
http://www.bbc.com/news/world-australia-32701311
I found this interesting, not entirelly on topic though.
“The Luritja people, native to the remote deserts of central Australia, once told stories about a fire devil coming down from the Sun, crashing into Earth and killing everything in the vicinity.
The local people feared if they strayed too close to this land they might reignite some otherworldly creature.
The legend describes the crash landing of a meteor in Australia’s Central Desert about 4,700 years ago, says University of New South Wales (UNSW) astrophysicist Duane Hamacher.
It would have been a dramatic and fiery event, with the meteor blazing across the sky. As it broke apart, large fragments of metal-rich rock would have crashed to Earth with explosive force, creating a dozen giant craters.
…
Earlier this year, another team of researchers presented a paper arguing that stories from Australia’s coastal Aboriginal communities might “represent genuine and unique observations” of sea level rises that occurred between 7,000 and 11,000 years ago.”
This is as big as the YDB event itself in the validation of catastrophism that it provides.
We got to present twice, once each day of the conference. The first day was the Great Lakes shoreline session. Second day was the planetary science session. We were well received both days, and got some good networking in with various members of the North Central chapter of the GSA. As an aerospace and orbits guy I was somewhat out of my element, but it was great fun to immerse in science and learn-learn-learn. And I got to use the laser pointer while Mike did all the talking.
I like earth science, but is seems more exciting when stuff flies in from space and blows things up. Interestingly, the assumed 60 Billion tons of AustralAsian (AA) tektites pale in comparison to the mass of 1600+ cubic kilometers of Carolina Bay sand, which in turn pales in comparison to the 10’s of thousands of cubic km of ice which seems to have propelled all the silica to the bays and the far side of earth from China to to Antarctica.
Also of note are tektites which have been found in N. W. Canada w/ composition that seems to match the AA profile upon initial tests, and tektites now found in Central America which are identically coeval with the AA event dating of 786 ka. The steep vertical launch angles comparable to those reaching China through Antarctica from Saginaw Michigan, but instead reaching these two Western Hemisphere tektite locations, turn out to be almost identically symmetric about the Saginaw Bay centerline azimuth of ~220 degrees. As an orbit analyst, I get a strong message from that element of the imprint. Stranger than fiction, you just can’t make this stuff up.
Tim Harris
Wow. Allow me to say that backward: Wow.
Right or wrong, thank you and Mike Davias so much for sticking your necks out, Tim Harris. I am in awe. You are awesome.
I totally agree, George.
We don’t have a report on how well the presentation went, do we? That would be nice to hear about.
Ooops! Dammit! I didn’t see Tim’s comment listed, so I didn’t expect that he had. Once again, my bad… 🙁
….So Davias is putting the formation of the Carolina Bays at >780ka….
my 2 cents says the Carolina Bays don’t have that much time on the “erosion” scale. I would think that after 780ka and earth uplift/down thrust, etc., there would be way more destruction of the outlines of the bays….
I cant help but notice that the putative date for this imapct is just before, geolocically speaking, the eruption of the Long Valley Caldera. Once again a major volcanic event happens in an era of a major impact.
David – I am with you on the dating thing. OSL dates don’t go back nearly that far, though the CBs have been notoriously difficult to date.
CevinQ – Interesting about the Long Valley caldera. It’s worth looking into. My thing about the date is the Brunhes–Matuyama reversal, pegged right at the 780kya time. I don’t believe in coincidences. So the next question would be: “How does an impact correlate with a magnetic reversal?” followed by the second question: “If ONE magnetic reversal/excursion correlates with an impact, what does that suggest for other reversals and excursions?”
It’s the same thing with the YDB: If the Younger Dryas onset is correlated with an impact (and the forensics says most likely), then what does that suggest for those other big jumps that show up in the Greenland ice cores? Do THEY argue against the impact hypothesis for the YD onset? Or do they argue instead that we should look at possible impacts for the other big, rapid climate changes?
None of these things can exist in a vacuum. Correlation in one time MUST mean that correlation in other times must be investigated, too. Of course the orthodoxy will investigate within the confines of uniformitarian “closed-system” processes. And alternative researchers will investigate within the confines of zero-point energy processes or electric universe processes. We here prefer neo-catastrophist processes.
But perhaps the Brunhes–Matuyama reversalAA Tektite impact correlation is spurious and coincidental? Don’t bet on it. Big reversals are rare things – averaging about one every 275,000 years or so in the last 5.25 million years. To suggest that one just HAPPENED to occur at the same time as the one-time tektite impactor is something like a 1:10,000,000 chance, allowing for a 20,000 year uncertainty for the tektite event. I will bet on the 9,999,999 vs the 1.
Steve,
Several years ago I noticed the there was a magnetic feild reversal at roughly the same as the Long Valley eruption, which by the way is not linked to other local volcanic processes.
The dating of these separate events, though seemingly separated by tens of thousands of years, really occur simultaniously when speakingi n cosmic time scales or fall within each others margin of error.
Are you familiar with the uranium inner core theory,while soundly derided by the geology community, it goes a long way to explain a few odd things about the the earths core.
One of the more interesting facets of the idea is, at the boundry between the outer core and the mantle, a mineral forms, uranium silicide and is dimagnetic and will not allow magnetic fields to propogate.
The buildup of this mineral is patchy as it forms a shell around the core. Since this material does not propagate magnetic fields, this patchy distribution might have something to due with the “wandering” poles that precede a polarity reversal.
One article I’ve read on the subject went so far as to say that as this shell builds up around the core , the rotation of the core slows , also weakening the magnetic field.
The cores rotation eventually stops as it is enclosed causing the magnetic field to collapse. But pressure builds up inside the shell from heat , as it is no longer transported away from the core by convection.
The uranium silicide has an interesting property, when the pressure and heat build enough it undergoes a phase change , it sublimates back into its constituent elements. Convection starts again and the core restarts rotation , in the opposite direction, thus reversing the polarity.
That release of of energy when the shell collapses has to have an effect on the earth.
So. I’m thinking that if you have volcano complex that is ripe to blow, this might kick it over the edge.
And let’s say, if per chance that the core is in a enclosed state , might a major impact introduce enough energy to cause it to go over the edge, setting up a domino effect?
I know it’s a lot of speculation, but having three rare events, that happen at nearly the same time can’t be coincidental.
CevinQ –
Good stuff.
The timing of things in geology are all subject to change with new data. No single date for anything ties that thing to a single specific time, even if people treat it that way. C14 and OSL and other dating methods will give several different dates for samples taken together from the same layer, so which one is correct? Probably none of them, though they may be close. And I am not talking about cimply error bars, either. Lab tests give one date, and without the error bars all sorts of “wow” is in the entire process and results. At 780kya, 20kya is close.
Van Hoesel was chastised by Kinzie for taking the single lab date – without the +/- – as gospel. And she deserved that chastisement.
Even when the C14 date is, say, +/-35 years, don’t take that as gospel, either, because the sampling method itself has variables in it. The lab test can only test what the field people sample. Surovell was a dunce in this regard – not even following protocols for taking samples. Daulton did what he normally does and did it well, from all reports, with what they gave him, but what Surovell gave him was garbage.
…Uranium core? It is my understanding that uranium is considered by the orthodoxy as part of the core. I understand it that the uranium provides the radiation that creates the Earth’s internal heat. That is not the case????
I DID just read something about some researchers discovering that there is an inner inner core. I will see if I can find that again. Maybe I remember it wrong. This is not the same article (it is from 2003), but it covers both points to some extent: http://www.spacedaily.com/news/earth-03k.html This is the article I’d read: http://www.dailymail.co.uk/sciencetech/article-2946138/Journey-centre-Earth-Scientists-planet-s-inner-core-core-own.html
…Magnetic fields in the core and mantle… I’ve always had a problem with the idea that the molten mantle and core could have magnetism. Why? Because magnetism requires aligned molecules, and Brownian motion at high temps is exactly the way to destroy magnetism. (That article talks about temps at 5000-7000°C – even with pressures keeping the iron solid, the Brownian motion at the molecular level should still be going on. The energy can’t just sit there doing nothing, IMHO.) In fact, paleomagnetism is based on the understanding that as materials cool they assume the magnetic alignment of the field around them – direction, dip, and strength. Thus it assumes that at high temps the magnetism is not possible.
But if magnetism is non-existent at temperatures that can be achieved in a home oven, then how can magnetism exist at the temps in the mantle and core? I don’t get it. The two principles seem mutually contradictory to me.
(For these reasons I keep expecting someone to discover that the Earth’s magnetism is only in the lithosphere. I don’t know yet of any principle that would argue that this is impossible. So I wait and see what develops on that front.)
…As to a layer that is diamagnetic between the core and mantle, this also confuses me. I would expect that there IS no magnetism there to block. Maybe the idea that Brownian motion has something to do with magnetism is too “junior high”, and that I am wrong.
As to “patchiness” of something at some layer, that is a novel idea, and one I think would be worth pursuing. Not only might it have application to magnetic pole shifts, but could also explain the patchiness of the levels, direction, and dip of the magnetic field as measured on the surface.
…I do not think I could sign onto any ideas that talk about the core stopping and then re-starting. While such an idea might explain some things, a mechanism for stopping the core and then restarting it seems like an impossibility. Orthodoxy disses any idea that the crust can stop and re-start, so it would seem very inconsistent, unreasonable, and illogical if they would ever accept that the core could do this.
…As to an impact doing something to the core, all the way through the liquid (though viscous) mantle don’t seem possible to me. The liquid would attentuate the energy and distribute it in all directions. With the energy levels that would be required to affect the core, it seems that the results on the surface would be catastrophic anywhere the energy made it back to the surface. And we KNOW that such energies DO return to the surface – that is what seismic testing and our entire understanding of the inner layers of the Earth are all about, measuring the energies that make it back to the surface (or don’t).
…”might kick it over the edge” — This “tipping point” idea is NECESSARY invention in uniformitarianism and its precepts. When the normal processes that occur in gradualism are so far below the threshold necessary for the changes that have occurred in the past, the orthodoxy needs to invent tipping points and imbue them with powers far beyond what they really are capable of. But that shortcoming does not stop them from crowbarring using these inventions and claiming them to cause all sorts of things that they actually fall far short of having the capacity to do. In order for INTERNAL forcings within a normally stable system to somehow organize and amplify themselves to perform such deeds is used so often we all allow it. But that doesn’t actually GIVE them those powers – they are ad hoc inventions and no more. But these internal forcings are preferable for them, ahead of EXTERNAL forcings. Externals are simply not allowed – even when Jupiter has gotten whacked 3 times in 21 years. As Frank Zappa and the Mothers of Invention used to sing, “It can’t happen here. I’m telling you my dear. That it can’t. Happen. Here.”
In other words, don’t count on such tipping points to kick things over. The tipping points don’t actually exist, except as ad hoc explanations and speculations. They’ve GOT nothing else, internally, so that is sadly what they use to (in their imaginations) explain catastrophic events.
Are WE right? Who the hell would KNOW? All the money goes to inquire into the gradualist speculations and none goes to explore catastrophic ones.
I’m sure you already know this …
I find it interesting that the KT impact occurred 66.043±0.011 ma, based on argon–argon dating, and the Deccan Traps (123,000 cu mi) were deposited 66.250 ma (Source Wikipedia). The Chicxulub crater is not antipodal, but is in the opposite hemisphere.
A similar correlation has been proposed between the much larger deposition of the Siberian Traps and an anitpodal impact crater (Wilkes Land crater in Antarctica) 500 ma.
The idea is that shock waves emanating from the impact site travel around and through the earth and are focused at the point on the opposite side. I gather that the geologic community does not support these ideas.
Noel –
A nice set of ideas.
I wouldn’t exactly go with the “through the earth” to the antipodal point thing, though. Only the p-waves from quakes can pass through the core, so all the rest gets shunted to much nearer surface locations. See http://www.astronomynotes.com/solarsys/seismicb.gif
But I take exception to the artist’s rendering in that image. Refraction does not curve waves within a material. Refraction happens on the CHANGE in density and material properties of two materials in contact with each other. IOW, the bending happens only at the interface. The curved lines are clearly telling the audience that the waves curve WITHIN the core or mantle. Given a homogeneous material in the core or mantle, the waves would travel in straight lines and bend only when entering or leaving each material. The effect may be the same, but that diagram (and almost all others) are not showing this principle correctly,
I took a good look at images (on Google) of this wave propagation through the Earth, and virtually every diagram shows these waves curving. Akkkk!
This is not to say that, because of the NON-homogeneity of the materials in the mantle and lithosphere, that there isn’t a lot of bending/refraction going on. But within a layer, heterogenity should balance what it does to waves – meaning some would go up and some down.
Also, if temperature and pressure are part of this, then THAT should be specifically included in such presentations. Not including such information leads the observer to conclude that waves bend into curves on their own – contrary to everything I’ve ever been taught.
Noel and Steve,
You might find this interesting,
”
Large Deep-Ocean Impacts as the Cause of Antipodal Hotspots and Global Mass Extinctions
Jon Hagstrum, U.S. Geological Survey, Menlo Park, CA 94025
(jhag @ usgs.gov)
The distribution of hotspots on Earth has a distinct antipodal character. Although hotspots are generally attributed to narrow upwellings from the deep mantle called ‘plumes’, detailed observations tend not to support this model.
An alternative model of hotspot formation, related to large deep-ocean impacts, is proposed which explains their antipodal distribution, and the coincidence of impacts, flood basalts, mass extinctions, rapid sea-level shifts, and abrupt ocean chemistry changes at or near the major extinction boundaries of the geologic record. The effects of deep-ocean impacts differ from continental ones in several major ways: they generate mega-tsunamis with >1 km run-up heights on hemispheric scales, they launch immense quantities of water into the stratosphere, and they likely generate much greater amounts of seismic energy due to the ‘mudcapping’ effect of the deep ocean. Impact-generated seismic energy is most intensely focused by Earth in the antipodal asthenosphere, and the resultant heating and melting, and fracturing of the overlying lithosphere, might lead to flood-basalt eruptions, rifting, and hotspot volcanism.
The return seismic energy is also focused beneath the impact site itself, and along with shock heating, melting, and fracturing, could cause ocean-is land volcanism subsequently obliterating the impact site. Mega-tsunami waves could be responsible for the apparent sea-level and observed ocean chemistry changes. The Deccan Traps, regression-transgression pulse, ocean isotopic anomalies, and great end-Cretaceous extinction might have been initiated by the oceanic ‘Socorro’ impact at 67-68 Ma, and the on-land Chixulub impact at 65 Ma was its coup de gr2ce. The greatest end-Permian extinction was also possibly a double impact event (both oceanic), with regression-transgression pulses, flood basalts, and mass extinctions occurring within ~5 m.y. at the end of both the Guadalupian and Tatarian Stages.”
http://pangea.stanford.edu/~jon/01/hagstrum.html
So other people are seeing the “Big asteroid hits followed by antipodal traps-style flood basalt volcanic eruptions” pattern we have been speculating upon here at the Cosmic Tusk.
We are in paradigm shift territory.
Big institutional science is losing uniformism to a new generation of researchers who have the “Next Big Thing” that also makes for great sexy disaster movies.
No, I am not kidding.
This is part and parcel of the climate change debacle hitting big science’s ‘street cred’.
How big science’s street cred is ‘melting like chocolate’ —
http://wattsupwiththat.com/2015/05/30/chocolate-covered-science-the-terrible-state-of-scientific-publishing/
Phys.org has an article on lunar swirls being tied to cometary impacts. The researchers chained off the effect of the LM rocket plume on lunar dust and soils it as it landed. Interesting photos. Cheers –
http://phys.org/news/2015-06-comets-mysterious-lunar-swirls.html
Here’s a 2004 Hagstrum paper with a nice map of the hotspots and LIPs (Large Igneous Provinces). Cheers –
http://www.mantleplumes.org/WebDocuments/Antip_hot.pdf
CevinQ and agimarc –
Before I go on with reading your not-long comment, I wanted to add:
“Although hotspots are generally attributed to narrow upwellings from the deep mantle called ‘plumes’, detailed observations tend not to support this model.”
That mantleplume.org site is a group of scientists who dispute the mantle plume hypothesis as it stands and how it is popularly presented. See http://www.mantleplumes.org/ – They subtitle it Discussing the origin of ‘hotspot’ volcanism I’ve been there before, and as I understand it their quibbles are semi-subtle ones that add up to an overall disagreement.
I add that not as any rebuttal, but to include another side to the discussion here.
As I understand their arguments, it might be a big deal. Plumes are considered the driving force behind moving continents.
In my brain, ANY proposed explanation for driving continents or the Gulf Stream based on convection as the initiating force is asking one of the weakest of all forces (convection) to explain some very big mass movements. I really cringe when I read such things. Convection in itself is quite weak, and then when one discusses convection in a viscous liquid (even water in this case) has to discuss the viscous resistance to flow. ONLY the net convection force is available to DO anything. In the case of moving continents, then one has to factor in the losses due to the inefficiency of magma plumes moving horizontally with only the drag against the underside of the tectonic plates available to actually move the plates. Add to that that the upward force of convection when translated into an expanding horizontal plume gets weaker with every kilometer – in an inverse square relationship. This makes the horizontal force so much weaker…
I am not saying out and out that the plumes moving continents is wrong, but I am not sure about it, to say the least…
…One more thing about plumes. One cannot look at magma upwelling in a volcanic eruption and equate that with a plume rising. The rising magma in a volcano is driven by SERIOUS pressure, not convection. And off the top of my head, I would guess that there are at least two magnitudes of differences in the available force, between an eruption and a plume of the same diameter. Perhaps three magnitudes. Perhaps five.
Trent –
I caught that WUWT “Chocolate Covered Science” thing, too. Biology and medicine are having a LOT of papers withdrawn in the last decade, with the amount of falsification of data/fudging of data being a big and common thing – and more common every month, it seems.
I don’t want to open up a can of worms here or hijack this comment thread, but personally, I apply the chocolate coating to CAGW, too, but not many others do.
A big issue to me is also the way researchers pander to the present paradigms so much. They fully buy into current paradigms. To me that is just as bad as fudging data, because they “retro-fit the data”, as it were, to crowbar it into the paradigm, instead of challenging the paradigm when it shows weaknesses. IMHO every research project should TEST the paradigm, probe the paradigm, looking for weaknesses, looking for ways the paradigm needs to be adjusted. Full acceptance of paradigms as they exist is bad for science, in my estimation. NO paradigm is 100% correct as it is first presented.
Thomas Kuhn talked about two classes of scientists, though I don’t think he gave them names. One was the frontier scientist, who discovers or develops new principles or processes – new paradigms. The other – which he said is the vast majority of scientists – are ones who are happy to do detailed work to find ways that the paradigm can be made to fit the data in more and more specific ways.
Kuhn said that the paradigm author should do two things:
1.) Come up with a concept that the great majority of scientists will sign onto, and
2.) NOT flesh it out all the way, but give others the skeleton of the idea (my phrase) for others to flesh it out in various ways.
agimarc –
A very good and plausible hypothesis by Peter Schultz about the lunar swirls. Thanks!
NOW, think about this:
Quite a while ago I surmised some reason that at least SOME comets are rotating sideways as they travel, with the outgassing causing this rotation. Not an end-over-end rotation but sideways, so that from the front the comet would look like a spiral.
Why do I think that? There are only a few places on Earth that have what are called Neolithic spirals carved in rocks. The main locations are in the British Isles and a couple of places not far from me in Mexico. Though separated by about 5,000 miles, the spirals are eerily similar. It brings up the possibility that people in both places saw the same thing(s).
Most of the time we see comets in a side view, because they are passing us by millions and millions of miles. Also, after the gasses escape and are away from the main body, they certainly seem to be pushed by solar wind away from the Sun, so we focus on that, because that gives us a BIG thing to observe.
But I asked, what would they look like from the front? I don’t know for sure. We see comets somewhat from the front when they are still far out from the Sun – but at that point the outgassing isn’t very much.
But whenever I hear people talk about outgassing from comets, I think of astronauts and their air nozzles that they maneuver with. And I think of the steam “engine” of Hero in ancient Greece, which simply went round and round. ANY unbalanced outgassing has to cause some rotation of a comets’ outgassing body.
I am not saying that all comets spin in this way, but that some certainly would – just by chance. Some would rotate end-over-end, perhaps, too. And many might spin obliquely (maybe most).
The lunar spirals look close enough to what I am envisioning to perhaps be due to the same spiraling of outgassing comet bodies.
***One other thing:
The Philae probe landing on comet 67P showed that the escape velocities of comets is REALLY low. Especially compared to the intrinsic velocities in the solar system.
Peter Schultz himself was quoted as saying that the Philae probe came within 15% of escaping 67P’s gravity. And it was only going 0.38 km/sec after bouncing – about 15″/sec. Phlae bounced TWICE. I think the third landing would have bounced, too, except that the probe may have hit on the side of bump, which sent it sideways instead of up. I read that the probe ended up on its side. That would be consistent with hitting on a non-flat surface.
I would be interested to find out how fast gases are nozzled out of comet bodies. I’d suspect that it is higher than the escape velocity or very near it. And that 0.38 m/sec was at the surface of 67P, BTW, and every km that the gas gets farther away, the lower the escape velocity is. I am pretty sure that by the time the gasses are visible from Earth, they are already long gone to a body the size of 67P.
The antipode thing…
My numbers on the antipodes listed by Hagstrum et al show this:
Assuming the latitude and longitude are exact degrees, the distance from exact antipodes average 870 km and 7.8° on a direct line.
That is not exactly antipodal. Without wanting to insult anyone (pleased don’t be), that is the kind of +/- one finds in astrology for oppositions and squares and trines.
I am not saying that energy making it around/through/semi-through to the antipode doesn’t happen. But why all of this variation? This 870 km offset (range 157 kms to 2439 kms) is troublesome. Hahaha – do “the vibes” get there? Why off-target? (Granted the Large Igneous Provinces are not each just a single point – which gives a lot of “wow” to the suggested principle.)
I also don’t agree on one of the hotspots in particular. I know quite a LOT about the Galapagos Hot Spot (also called the Galapagos Spreading Center and the Galapagos Plume). I’ve been reading up on that for months, on another issue. It’s funny how things in one area of inquiry can tie into other ones…
That is very near the juncture of the Galapagos Rift and the East Pacific Rise, and as the paper noted, it is RIGHT on the Equator. It is ON the Galapagos Rift and near the junction of three tectonic plates. The East Pacific Rise there and the Galapahos Rift are the fastest spreading mid-ocean ridges in the world. There is a LOT going on there. If you look at the map here – http://www.heatflow.und.edu/marine.jpg – you can see the level of heat flux, which is almost through the roof – the highest heat flux in the world. It is a terrifically studied small region of the ocean. It is where the first sea floor vents were discovered, and where studies right now indicate that there is a seasonality to the rise and fall of magma extrusion and heat flux there.
Hagstrum would need to explain why that spreading is not the cause of that hot spot.
Wow, believe it or not, I FULLY expected him to include the Azores, too. And he did. The Azres are STRADDLING the junction of three plates and three mid-ocean ridges – all of which are spreading, which is a good other reason for the hot spot there.
Outside of Ascensión Island along the Mid-Atlantic Ridge, no others on his hot spot list jump out as mid-ocean ridge, so that part is cool, mostly. He is finding hot spots in the middle of tectonic plates, and those need explanations.
Steve G,
A couple of asteroid impact plus basalt flood volcano articles to chew on —
1. Did dinosaur-killing asteroid trigger largest lava flows on Earth?
Date: April 30, 2015
Source: University of California – Berkeley
Summary: The theory that an asteroid impact killed off the dinosaurs 66 million years ago is well accepted, but one puzzle is why another global catastrophe — the huge, million-year eruption of the Deccan Traps flood basalts in India — occurred at the same time. Geologists now argue this is not a coincidence. The impact probably rang Earth like a bell, reigniting an underground magma plume and generating the largest lava flows on Earth.
http://www.sciencedaily.com/releases/2015/04/150430170755.htm
2. Massive volcanoes, meteorite impacts delivered one-two death punch to dinosaurs
Date: November 17, 2011
Source: Princeton University
Summary: A cosmic one-two punch of colossal volcanic eruptions and meteorite strikes likely caused the mass-extinction event at the end of the Cretaceous period that is famous for killing the dinosaurs 65 million years ago, according to two reports that reject the prevailing theory that the extinction was caused by a single large meteorite.
http://www.sciencedaily.com/releases/2011/11/111117141201.htm
Trent –
ScienceDaily seems to do this – or maybe it is my imagination – presentign something as actual when it is just the interpretation of one group of scientists.
“occurred at the same time.” – Ye-e-e-e-es and no… These dates from that long ago have so big of uncertainty/wow/+/- in them, asserting that things with the same numbers are really at the samen umbers have to be taken with SOME grain f salt. Both numbers are probably currently +/-8 My or more.
“Geologists now argue” — Really bad reporting. “SOME geologists” would be more accurate. If it was ALL geologists (as the phrasing reads), there would BE no “now argue” to it.
“reigniting an underground magma plume” — WHAT??? WTF does “reigniting” mean, when the phrase is applied to a magma plume? Obviously the plume’s fire didn’t go out. At worst the plume’s upward flow had been dissipated earlier (how would they KNOW this????) and they are suggesting that somehow the impact at Chixculub re-FOCUSED the plume, re-centered it. All of which needs to have some evidence besides speculation as to why the pre- and post- conditions existed and changed. (Have fun, folks, with that one…)
But showing what that means and coming up with some rationale behind it is SOME slog. As usual, ScienceDaily doesn’t have a link to the full paper, so if I am blowing it out my anal fissure, I don’t have much to go on except the rah-rah of the reporter.
From the Abstract:
Like I said, a lot of wow. Geologists are funny, in that “about a hundred thousand years of each other” is seen as coincident. To humans, 100,000 years is EIGHT times the history of civilization.
It is also unclear exactly what that quote is saying – 3 events spaced over 200,000 years, with 100,000 between #1 and #2, and then between #2 and #3? Or all within ONE 100,000 year time span? In the former, the time span is then 16 times the span of civilization. Either way, that is a LONG freaking tim. Maybe not to geologists – but it IS, for basalt and all other molten materials. How long does basalt cool on the Earth’s surface now? About a year? Usually less? But one thick modern one was still not fully cooled and hardened after 29 years.
In reading on the Deccan Traps, goodness, no two sources use the same dates. Some put India as an island in the Indian Ocean at 65-60 Mya. THAT makes all of this a bit more interesting!
IN ADDITION, they have to give good rationale as to WHY basalt flows (otherwise known as “lava” – literally) in India COULD kill the dinosaurs all around the world – at least those areas not directly affected by the impact in the Yucatán. Just because lava flows over the landscape doesn’t mean that it has world-wide consequences. It’s a nice idea, if they can fill in enough of the blanks. But MST lava flows are basaltic, with a small percentage being silicic (silicon flows).
In looking at the Deccan Traps, it is difficult to think that their horizontal layers were not laid down one discrete layer at a time, over MANY long periods. That makes one ask:
If the Traps were laid over a long period (a million years?), then why would ONE of them be special and part of the end of the dinosaurs? (This is analogous to the argument about the YD impact needing to explain why it is a special case, re the severe warmings and coolings of the earlier 37 ky shown in the Greenland ice cores.) At the moment it appears that the K-T impactor hit somewhere during the long period of the laying down of the Deccan Traps. So, what special characteristics of the Traps at THAT time would add to the Chixculub impact chaos? The impact itself did not happen over a million years, obviously, so the connection of the two events in their minds really seems weird.
BTW: There are a lot of speculative papers out every year in all sorts of disciplines that end up with their ideas going nowhere.
This paper seems to have enough caveats in it to constitute a speculative paper. There are evidently a lot of other people who think along these lines, too. But I keep seeing sizes of the Deccan Traps all over the map, plus ages varying all over the place. Somewhere in that mix, the 65 Mya date happens, and they connect the two.
Don’t get me wrong: I think that such widespread effects CAN be triggered by such an impact – though I don’t yet have a full gestalt on the how and why. But just because someone discusses a possible similar impact/geologic event connection doesn’t mean that we have to rubber-stamp their speculations. I know that they won’t rubber-stamp our un-credentialed speculations, if and when we pop up with any… LOL In general, they (generic “they”) have given the YDB Team hell. And it has LAB results! And VERY narrow dates coincidental with the YD onset. These Deccan Traps-KT Impact connections seem much less well-founded.
I DO need to see how the Deccan Traps fit into anything. One more thing to study up on!
Sorry I can’t leave this there…
From the Abstract:
I just refreshed myself on newtons and joules this week, so this stuff is fresh in my mind.
And my mind read that and went “WTF??!!”
Now, having dealt with forces my entire career, I have a REALLY good practical knowledge base about what constitutes “sufficient” force in many applications, perhaps most. In the real world. (This says “seismic modeling”.)
If they had said something that translated into maybe 500 PSI per cubic meter or 200 watts per cubic meter, I would have had a lot of reason to question them. BUT…
Let’s begin…
1.0 joules/cubic meter – how big is that?
A cubic meter is a LOT of volume, to begin with. Over 35 cubic feet.
A joule “is equal to the energy transferred (or work done) when applying a force of one newton through a distance of one metre (1 newton metre or N·m).” [Wiki]
Okay, 1 Joule = 1 N*m. That is DAMNED small.
Okay, now how big is 1 newton?
A newton is 1 KG applied for 1 meter for 1 second. [1 N = 1 kg⋅m/sec^2] [Also Wiki]
That is like me pushing a loaf of my whole grain bread for one meter and doing it in one second. (Or 2/3 of a skinned Tyson chicken.)
OR, 1 newton = 1 kg*m^2/sec^2 = 1 Pa*m^3 = Watt*sec [Wiki]
This gives us three ways of looking at that. Newtons, Pascals, and Watts.
Now, I am her to tell you guys that 1 of each of those are REALLY feeble forces/pressures/powers. F-E-E-B-L-E
1.) NEWTONS. A newton equals less than a POUND. A LOT less. 1 newton equals 0.2248 lbf = 0.2248 pounds, as we Americans know pounds. That is about 3.6 OUNCES of force. Yeah, THOSE kind of ounces. Less than the weight of a Quarter Pounder. LITERALLY. NOT counting the bun or pickle or cheese or condiments.
2.) PASCALS. Now, pressures in geology usually are up in the MILLIONS or BILLIONS of Pascals. Why? Because 1 Pascal is so damned small. One pascal equals about 0.145 PSI. It takes about SEVEN of them just to make 1.0 PSI. It says above that a Newton is ONE Pascal per cubic meter. That is 1/7 of a PSI in a volume of about 35 cubic feet.
3.) WATTS. In terms of mechanical POWER, 1 Watt is 0.00134 horsepower. REALLY LOW. It is also 0.737 ft-lbs/sec. To give you an idea of that, it is the torque of applying 12 ounces of force to sideways at the end of a mechanical arm 12 inches long. YOU CAN DO THAT WITH YOUR PINKY, and not even strain it.
Guys, those are MINISCULE forces/pressures/powers. We aren’t talking much above FEATHERS here.
And this paper asserts that 1/7 of 1.0 PSI pressure in 35 cubic feet is sufficient to bring on the basaltic flows of the Deccan Traps.
Or that 12 ounces of torque on an arm 12 inches away from a pivot point is enough.
Or that 3.6 ounces of force straight ahead is enough.
I beg to differ.
With those three different ways, I am leaving myself wide open if I made a booboo. If I did, correct me.
Geology deals in HUGE pressures and temperatures and force and masses. YES, if you take that 1/7 of a PSI in 35 cubic feet and multiply it by the gazillion cubic meters of lithosphere (the crust down to those “200 meters” they talk about.) But that doesn’t change the DENSITY of the pressure. It is still like 0.0041 PSI per cubic foot.
And they aren’t even talking about ONE joule. They are talking about 0.1 UP TO 1.0 joule. So, all the little numbers I just came up with? Cut them down by about half, on average.
I might be able to generate that much force with my EARS. Or maybe about the force of butterfly wings flapping (joke).
Gonna cause ONE MILLION YEARS OF BASALTIC FLOWS?
Either they are stupid or I am.
What am I missing here, guys?
Somebody misplaced a decimal point or has NO idea about proportion whatsoever. Maybe it is me?
Maybe I am piling on, but this paper seems like one of the most speculative paper I’ve seen – maybe ever.
Waffle words and speculative phrases in the Abstract:
“suggest that”
“may have occurred”
“suggests that”
“could have”
“may have been caused” – that passage is a doozy.
“It is therefore reasonable to hypothesize”
“might have”
“may account for”
“is consistent with” – have they discussed what ELSE it may have been consistent with?
“combine to indicate that at approximately Chicxulub/Cretaceous-Paleogene time”
“may be able to either confirm or reject this hypothesis” – WHAAAAT???
“might help to determine”
I am really disdainful of the following assertion:
“…historical data document that eruptions from existing volcanic systems can be triggered by earthquakes”.
Bull. BULL. If THEY can assert the use of historical data and claim that earthquakes CAUSE volcanic systems to be triggered – and I am sure they put something in the body text to support it in some way(s) – but no one should accept such a wild and baseless claim. They may show correlation IN TIME, but “correlation does not prove causation” and anyone asserting that it does is fooling themselves. If they can do that and get away with it, then all the ancient accounts of comets and impacts and floods should equally be allowed into the literature.
This next abstract passage is completely contrary to what is seen in the Deccan Traps:
“…a huge pulse of mantle plume–derived magma passed through the crust with little interaction and erupted to form the most extensive and voluminous lava flows known on Earth.”
The word “traps” in the name is said to be from the steps – the layers – in the deposits. Thus, it is quite clear that each quite horizontal trap/step is a separate basalt/lava flow. There were, therefore, hundreds or thousands of such individual and sequential flows. To assert in any way that the volume of the entire traps came in one fell swoop is utter and silly nonsense. Their assertion is like saying that all sedimentary layers were laid down at the same time. Which is HOGWASH. Which is honestly what I see in this entire Abstract.
A “huge pulse”? “most extensive and voluminous lava flows”? Duh, yes, if you ADD them all together. Individually, hell no. Not true at all.
With waffle words/speculative words in almost every sentence of the Abstract, removing those guesses and maybes leaves almost nothing of substance. HOW this ever passed review I can’t imagine (but I would suggest a pal network – especially since it seems several groups of authors have been writing stuff suggesting the same thing as this paper’s abstract does).
This was atrocious. WHY is ScienceDaily pushing this utter crap science???? Richard Feynman must be turning over in his grave…
“Everyone here is now dumber for having listened to this. I award them no points, and may God have mercy on their souls”. […paraphrased from Billy Madison]
From IMPACT CRATERING THEORY AND MODELING FOR THE DEEP
IMPACT MISSION: FROM MISSION PLANNING TO DATA ANALYSIS
Richardson et al 2004
at http://www.jerichardsonjr.info/Papers/jerichardson_SSR2005.pdf
This whole passage is something we can really respect. The author is saying we don’t know squat, which is real honesty. In addition, he is saying that the Deep Impact project itself is an experiment that will – expectedly – teach us some things, and then we will know more. “The experiment itself must answer these questions.”
In other papers about craters, by Peter Scultz (the man gets around!) – at least I think it was him – it was stated that the cratering process depends very, very little on the gravity and almost all to do with the velocity and density of the impactor and target materials.
I wonder if Richardson found this out, too. Maybe I will find out…
Steve – cometary rotation
I would expect the outgassing from cometary jets is by definition greater than escape velocity for the bodies. Otherwise, we wouldn’t see things like comas or tails.
As to the jets themselves spinning the bodies up, there are so many variables that I couldn’t hazard a guess. For example, some regions as we see on 67G outgas and some don’t. Add those impulses over time to whatever the rotation / tumbling rate of the body and it will change.
Not only are spirals depicted in in neolithic drawings, but so are swastikas, probably for the same reason – face on view of comet(s) with jets rotating around the axis of view.
Here’s yet another piece: Ever hear of the YORP effect? This is the differential heating of a small body which over time eventually causes it to rotate faster. It is most common among the asteroids and has been blamed for observed disintegration of a few of them as the rotation rate exceeds the physical strength of the body. As I understand YORP, it is not a player for bodies in the outer solar system or farther out. But for the asteroid belt and closer, it is a player and would impact comets while they are closer than say the orbit of jupiter. Cheers –
http://www.space.com/3543-sunlight-increases-space-rock-spin.html
Steve – antipodes
Good point and a lot of work to plot everything. Problem with all of that is that everything moves – the plates, the hot spots, and the mantle plumes, albeit slowly. I suppose I am surprised that things are as close as they are.
There are additional disagreements about things that may or may not be hotspots. You know about the Galapagos as a triple junction. I know a bit about New Mexico and don’t believe there is a Raton hot spot. Believe it is a function of the intersection between activity along the Jemez Lineament and the Rio Grande Rift over time. Cheers –
Chers –
I had to refresh my memory about YORP.
From the 2007 YORP paper Abstract:
Honestly? This almost sounds like wishful thinking. When I see phrases like “is best explained by”, it always REEKS of cherry picking of ideas and causes. I WOULD definitely expect to see in their papers how “is best explained by” compares to the OTHER possible explanations – and why the others are rejected.
I don’t have the full text, so maybe there is more to it. But I DO find that one author (Kaasalainen) shows several other papers about other asteroids being affected by the YORP effect. That also suggests a bit of tunnel vision – that or a crusade of some sort to show something special about the YORP effect.
CRINGE: “We show that for υ = 0, a constant-period model, the whole dataset of lightcurves cannot be satisfactorily fitted. However, when relaxing υ in the optimization process we obtain an excellent agreement between the model and observations. The best-fit value υ = (1.15 ± 0.15) × 10−8 rad d−2 implies that Geographos’ rotation rate accelerates by 2.7 ms yr−1.”
Yowch! The lightcurves IN THE MODEL EVEN “cannot be satisfactorily fitted”. SO what does the guy DO? He fudges the parameters until he gets one that “fits” what he wants to see. TERRIBLE SCIENCE! When they do such things in medical research, people lose accreditation! (It’s bad enough that the guy uses MODELS. But he then has to screw around with them to make stuff “fit”. Shades of Climategate.
As to the principles…
[Wiki] “The Yarkovsky effect is a force acting on a rotating body in space caused by the anisotropic emission of thermal photons, which carry momentum. It is usually considered in relation to meteoroids or small asteroids (about 10 cm to 10 km in diameter), as its influence is most significant for these bodies.”
[Wiki] YORP — “In the 19th century, Ivan Yarkovsky realised that the infrared radiation escaping from a body warmed by the Sun carries off momentum as well as heat. Translated into modern physics, each photon escaping carries away a momentum p = E/c where E (= hν) is its energy and c is the speed of light. Radzievskii applied the idea to rotation based on changes in albedo[1] and Paddack and O’Keefe realised that shape was a much more effective means of altering a body’s spin rate. Paddack and Rhee suggested that the YORP effect may be the cause of rotational bursting and eventual elimination from the solar system of small asymmetric objects.”
So, after refreshing, my brain says that YORP is not ONE cause, but THREE possible forces – one is infrared light, one is albedo (in general?), and the other is shape. Yarkovsky talked about the DELAY between solar energy in and infrared energy out, but ONLY on a body that is already rotating. By asserting all THREE forces, the YORP dudes seem to me to be equivocating, to some degree, if not totally.
But note that if a body is not ALREADY rotating, the effect is not applicable.
It seems to me that for fast-enough rotating objects, the delay in infrared emissions might be enough to actually RETARD further increases in rotational rate. In those cases, then, this might constitute a limit to the increase in rotational rate.
As to the shapes and such, there is this in Wiki:
“Note that the YORP effect is zero for a rotating ellipsoid if there are no irregularities in surface temperature or albedo.”
It is not comforting to hear that the effect seems to apply to BIG asteroids and little ones, but not to the average ones. It strongly suggests that there are elements involved that are not understood very well. The Wiki article goes into this a little, and that they think it is proof of the effect. Again, I don’t have the paper(s) available.
But why does it almost not work on the small 2000 PH5 but is VERY strong on 1862 Apollo which is 1400 meters across? That even seems contradictory to the other claim [in Wiki] that mid-sized asteroids are not affected by the YORP effect. WTF?
These things are always interesting, but some things keep hitting me the wrong way and waking up my skeptical/cynical side. . .
What can I say?
agimarc –
As to the outgassing velocities, I am with you on that. The escape velocities are so darned small, NOT exceeding them seems to be more difficult than exceeding them.
As to the comas and tails being evidence of >escape velocity, I wouldn’t NECESSARILY think that that is true, but with escape velocity shrinking with “altitude”/distance is such evidence even actually necessary?
[THIS is one reason I could never see how an expanding universe could stop expanding and slow down and re-collapse. The escape velocities of the bodies – even at close distance – is NOTHING, compared to the already “measured” out-going velocities. And with increased distance, the escape velocity SHRINKS. So HOW is it supposed to pull stuff back to it when it couldn’t before, when the things were closer? None of that ever made sense to me. Shirking escape velocity plus increased D equals LESS gravitational force, not more. I won’t even go INTO their ida about the velocities INCREASING, which seems just as bozo – to my still Newtonian mind…]
Back to Philae landing on 67P…
http://www.bbc.com/news/science-environment-30022763 – Moment comet landing confirmed
This is the moment that the ground crew found out – mistakenly, it seems – that Philae had landed on 67P. I THINK this is the first bounce.
That was November 12th.
But in the same batch of videos, the BBC also has THIS one, from November 13th:
http://www.bbc.com/news/science-environment-30034060 – Rosetta: Battery will limit life of Philae comet lander
And this one, from December 4th:
15 secs: Fears over Rosetta comet probe
Text from the video:
“Why are Rosetta comet probe scientist worried?
After bumpy landing, probe settled in a cliff’s shaddow.
It is using batteries to send pictures.
Fear of cliff blocking light to recharge batteries.”
OUCH!
This image shows what Philae was heading toward: http://ichef.bbci.co.uk/news/624/media/images/78956000/jpg/_78956538_welcome_to_a_comet.jpg It is no wonder it eventually ended up tilted over, with one foot in mid air.
They went in at about 1m/sec, and I don’t blame them at all. But even that was too fast to stick the landing. And Philea was “in mid-air” after bouncing before anyone knew there was a problem. And its final landing – its third touch down – was 100% out of control.
At the same time, don’t we need to ask WHY they settled on 1m/sec? It BOUNCED 1 km high and almost reached escape velocity. I have to seriously ask, “Why didn’t someone see that 1 km/sec was too fast?”
They had redundant methods of KEEPING it on the surface, it seems, but NONE for GRABBING hold in the first place.
Remember the old calculator programs for Moon Landing? It seems hard to believe that 40 years later they couldn’t stick a landing. Haven’t they learned anything?
ANY bounce at ALL would mean that the landing would be uncontrolled. If I was head of the project director, he’d be fired. WAAAY too much time and way too much money and effort, to have this kind of outcome. The landing team should have a BIG blot on their record.
The one video at http://www.bbc.com/news/science-environment-30033334 – All systems ‘GO’ for comet probe Philae has this admission…
“We don’t quite know where Philae is yet.”
That was December 4th – three weeks after “sticking the landing”.
This all was the ESA. I wonder if NASA is suppressing a smile, seeing someone ELSE screw up a landing.
(I don’t think this was a matter of confusing imperial units with metric, like happened once in the past. But WHO in science let’s anyone calculate anything in imperial units, anyway? I thought everyone learned metric units and used them all through school.)
Now take that 1 km/sec bounce off of 67P and project that to incoming rocks coming at 20 km/sec.
Then take THAT and project that back to the planetary nebula and the Accretion Theory. Anything =differnet? No.
1. Things that come in too fast, do not stay “landed”.
2. Things that come in REALLY fast, excavate craters, removing 250 times as much material as the incoming rock’s mass.
3. Almost ALL of the ejecta will also exceed escape velocity. Never to “land” again.
4. Such collisions add a negative amount of mass – meaning the REMOVE mass.
5. REEMOVING MASS means – by definition – that such collisions can NOT contribute to building UP of mass of a planetesimal.
Everything is backward in the Accretion model.
So how is it the currently accepted model?
Speaking of Philae…
At http://www.theglobeandmail.com/technology/science/comet-lander-philae-awakes-from-hibernation-communicates-with-earth/article24951792/
there is the news that Philae finally had enough battery charge to send a signal to the Rosetta “mother ship” which was relayed to Earth.
For some reason the scientists seem to be ecstatic about this. But this doesn’t sound like much good news to me:
“The 85-second-long signal was picked up at 10:28 p.m. local time at the European Space Operations Centre in Darmstadt, Germany. Before it cut out, the signal conveyed enough information to reveal that Philae survived its seven-month hibernation intact and is still capable of waking itself up whenever it has enough power to do so.”
Doing a bit of math, it took since November to June to charge up enough for 85 seconds of SIGNAL. Communications is about the least energy drain. That isn’t good news. It depends on WHY the wake up only seemed to last 85 seconds – which they aren’t sure about at the moment. If the rock/wall next to Philae is blocking the signal it’s possible there is more energy than seems apparent. That rock wall may be blocking the signal being sent to Rosetta some or most of the time.
Whether that is the case or the solar panels aren’t getting enough light to charge the batteries isn’t known, but one has to assume that the way 67P rotates if the panels had enough light, then there should have been earlier wake-ups, because the open window to Rosetta probably appears every rotation. That is my logic at the moment.
So, if the window to Rosetta is open even only 10% of the time (my guess), then if enough charge had accumulated earlier, the signal would have happened earlier.
Since that didn’t happen, it makes me lean toward the solar panels being in a very bad orientation – and that the 85 seconds of charge in 7 months really WAS all the charging that was possible. That is not good.
“The key question, he added, is why the signal lasted only 85 seconds. ‘In principle we should have received a longer [communication] slot if there was enough power available.’”
67P is rounding the SUN in about 2 months. Putting a happy face on the situation, the scientists suggest that Philae’s rock wall will actually SAVE the probe from the Sun’s intense light – and that this might make a longer life for Philae possible. At the moment, that sounds really Pollyanna.
But if Philae took 7 months to charge up for 85 seconds of signal, that life sounds like it is going to be mostly in a coma. The closer to the Sun, the more light energy will hit the panels, during the time the panels have rotated into a Goldilocks position. So there should certainly be MORE energy density, meaning faster recharges. But it doesn’t take much to improve on 85 seconds in 7 months. Even if that “grows” to 85 seconds per WEEK – an increase of maybe 42-fold – there are only about 16 weeks left. 16 times 85 usable seconds is not much – 1360 seconds, about 22 minutes plus…
Good luck if this is anything close to what happens. All that way for so little results.
I don’t think it is really feasible, but I wonder if they’ve thought to use Rosetta’s solar panels to collect sunlight and then transmit some of that energy to Philae’s panels. PROBABLY NOT POSSIBLE. But personally I think it is a design function that should be built into the mother ships and probes – at least doubling the possible energy collected if both are working, plus giving an extra way to charge the probe’s batteries in case something like this happened. If there are no problems, then the extra energy would allow for a LOT more activity by the probe. Not only that, but the mother ship almost certainly would always have full sunlight, whereas the probe on a rotating comet would be in darkness half the time or more.
If that isn’t done, I’d have to wonder why not. And if it IS, then they would be able to wake up Philae much more easily and often – and keep it going LONGER when it is awake.
In addition, if the probe’s panels have to rotate around with the comet’s surface, then the ANGLE of the panels would suck most of the time. The ones on the mother ship could be turned to an optimal position and kept there. So it doesn’t make any sense, then, to depend on the panels of the PROBE to collect the energy. The panels on the mother ship should be the ones providing most of the energy.
I am just going by what I am reading. So maybe I am missing something. . .
Steve,
Thank you for highlighting the current events on 67P Churyumov-Gerasimenko.
Regarding the Rosetta/Philae, I accidentally happen to be very familiar with that particular spacecraft and also of comets and NEOs in general, so I’ll put my 2 cents worth of a comment here to clarify this issue. Perhaps someone from ESA might read it and get a useful hint that they seem to be missing thus far.
1. Philae has an instrument (radar), designed to ping through the entire comet. It is there to study the nucleus. This can work if there is enough power, so obviously there it isn’t. There are only 24 W of power at present. 5 W are needed for computers to reboot, 5 for science and rest for heating and communication. The temperature is -35 degrees C.
2. This spacecraft is really 2 decades old technology. Don’t expect it to have lasers or to perform other XXI century tricks. It was designed and built in 1990s.
3. ESA still don’t know where the Philae is. It is a refrigerator sized block lost in some ravine on a 4.5 km wide comet.
4. Note to ESA: The probe ended in a remote dark ravine, far out of sunlight, because you forgot to take into account the winds!!!
When ices evaporate in a vacuum, and they do on an active comet, the gases go out with a speed of about 700 km/h. This is tornado speed. The density of gases is not great, but the gravity is weak as well, so the lander was virtually blown into some space without sunlight, where the winds were weakest. You should have fired your harpoons when you had the chance. Loose object in a windy place would always be blown into a dark corner. That is a lesson to be learned for the next time. To find Philae, take a look at dark cracks and crevices, or perhaps in shades of large boulders. It should be there somewhere.
5. The Rosetta should be credited for getting the first true image in high resolution of a comet. That alone was worthy of a quarter of a century of work. First ever.
6. If the Philae is located, there are tricks that can be performed to make it operational. It still has 2 harpoons. They can be fired to move the lander away and maybe to attach it somewhere else. I’ll give this 5% chance of success, but better that than nothing.
7. When operating a spacecraft, the time delay is significant. It is like playing chess: you make a move, than wait for several minutes for your oponent to make a move, then you think for a few minutes, make up your mind and make a move,… It is not like a video game. One wrong command and the spacecraft could be damaged or even lost. You can also loose a game of chess if you make a single wrong move, so this is comparable. However, the stakes are higher with a spacecraft, then they have ever been with a game of chess.
‘@Steve – it’s not that it took Philae took 7 months to charge, it’s that it took that long for the comet to move close enough to the sun long enough for the batteries to recharge. Think of it like you think of seasons – when 67P is close enough to the sun, certain things happen. When it is far away, those things don’t. In this case, it woke up this weekend, roughly 2 months from perihelion on 13 Aug. I would suggest that it should be active thru mid-Oct before the orbit carries it too far and the insolation angles change too much.
I am guessing the quick cutout of transmission was more tied to the tumbling rotation of 67P and Rosetta’s orbit around it. I cannot tell if the transmission was relayed or received directly from the news coverage. If they have a suggested location, then they can download the rest of the observations from memory assuming onboard memory is not corrupt. They claim to have received some 300 of 8,000 data packets in the initial transmission.
There is always good news from bad events. In this case, had they landed Philae successfully, it would have overheated by March. Appears they may have it available throughout perihelion – the most active period for outgassing and dust ejection, which was not expected due to its partially shadowed location.
With the luck these guys are having, I wouldn’t be surprised if a gas jet opens up near the orbiter and sends it back into space. Cheers –
Zoran –
Thanks for all the info. I am not sure about the ice evaporation and velocity. I will take your word for it, even if it sounds a bit high. Yes, very low density, so not much effective force. But the accounts so far don’t even talk about the outgassing. They only talk about a bounce (Peter Schuiltz said it was about 1 km), and then a lesser bounce. And much of that bouncing was during the transmission time, when they didn’t know WTF was going on with it. (Like an hour and 50 minutes or so.)
Though they claim it a success, I sure don’t. The harpoons seem like not a very good idea, but I don’t know the particulars.
Yes, it is 20-year-old tech. And Voyager was like 1960s tech – computers doing like 100 bytes/sec or so… and memory capacity like a dinosaur…
aginmarc – Thanks, too! But if Philae charged just because of closer to the Sun, then the 85 seconds should have repeated LONG before they had time for the press release about the 85 seconds. Maybe it isn’t 85 seconds in 42 weeks or so, before, but if it was only because it’s getting closer, why isn’t there a second press release about a second transmission? (Or is there? A check just now didn’t turn up anything…)
If I understood your point, yes, the article DID say in there that the signal was relayed via Rosetta.
I HOPE for the whole team there that you are right and that it will now be awake a lot. We will find out soon. The quick cutout THEY understand like you do. And I know that that is all part of it all, the rotation of the comet and where is the probe then, relative to Rosetta. But that is certainly not the only interpretation of what has happened. But if it was 85 seconds of good line-of-sight, then 85 seconds later there should have been another transmission, yes? What am I missing?
As to a suggested location, at one point it said that they have eliminated all other possible locations, so they THINK they know where it is, while admitting that they don’t accept the process of elimination as any proof of it.
Hahaha – about the outgassing jet sending it on its merry way. VERY possible. Seriously LOW gravity. (One of my main points against the Accretion theory… Someone was telling me the other day that the non-early ejecta velocity from a 20 km/s impact was about 3.5 km/sec – about the speed of some high-velocity bullets. Philae bounced at about 0.38 METERS per second. Since that is about a normal impact velocity possible “out there”, too, then one should expect that ejecta velocities from cratering collisions of planetesimals would be about that high, too. Picture bullets going outward and the ultra-low gravity of 67P trying to pull the bullets back. It ain’t gonna happen. Compare that 20 km/s to the 1 METER per second of the approach of Philae onto 4.2 km 67P. I just can’t wrap my brain around ideas that that can accrete anything at all. It would all be lost out into space, never to come back. Pardon my obtuseness… Reality doesn’t change, just because it was 4.5 billion years ago or so. Material strengths are what they are, and the law of gravity hasn’t changed – I don’t think!)
‘@Steve –
Conflicting stories on who transmitted what. ESA claims the signal was received from Philae itself, which is but one of many explanations for the timing of the transmission.
Don’t think you are missing anything. Though the rotation of 67P is more of a tumble than a predictable rotation around a single axis of motion. As I understand it, there is movement around all three axes of motion. Once you couple movement around two axes of motion, you induce movement around the third.
We’ve gone round and around on the accretion vs exploding planet argument a time or eight with little to no progress. Not really interesting in making yet another circuit, but what the heck ….
Would you accept the notion that dist particles will tend to clump via electrostatic forces (as observed on ISS)? If so, assuming you started with an accretion disk, would then the initial velocity distribution between adjacent particles and bodies be low (as observed in the Saturn ring system)? If you accept that, then sometime along the time of growth or embedded bodies impact switches from constructive to destructive, though that would be a sliding scale based on the size and energy of movement of what hits what. For instance, a whole lot of little objects can hit and stick to a big object while a big object hitting a big object with sufficient energy will disrupt both for at least a while, not unlike the earth – Thera collision creating the moon. Perhaps the question is not what hit what; rather what was the energy distribution between bodies and how did it vary over time?
I suppose the largest difficulty I have with the exploding planet is a chicken and egg question – which comes first? And if the exploding planet comes first, how does it get there? Cheers –
Agrimarc: I’m sure the universe is full of bits, pieces, chunks and out right blockbuster debris from the very beginning of the beginning. Any piece or combination of pieces can come screaming in or lazing in at any time unannounced from any where. It doesn’t necessarily have to come from our solar system. There have been enough explosions of stars, planets etc. to fill the universe with debris for collisions. At this this point in time I don’t think it matters whose on first. I wish to thank the ESA for there multi-billion euro example of strengthlessness. I’m finally able to wrap my mind around the concept. Steve has pounded this at me for ever and I would think I had it but questions would come to cast doubt on it now talking about the lander hopping to a landing at the low velosities listed, I GOT IT!!!
agimarc – “Though the rotation of 67P is more of a tumble than a predictable rotation around a single axis of motion. As I understand it, there is movement around all three axes of motion. Once you couple movement around two axes of motion, you induce movement around the third.”
Really? Don’t the angular vectors add up into ONE angular vector?
Is some of it WOBBLE? Or nutation? Are those the other two motions?
Agimarc –
I do appreciate your effort at discussing this. Seriously.
Electrostatic forces – might that be just a bit too “electrical universe” for the orthodoxy?
But answering the question, electrostatic forces of objects flying around like – no, much faster than – bullets — that one I don’t see, though I am willing to be educated.
Do we observe such electrostatic attractions now? That are strong enough to overcome, say, even 1 km/sec?
HAHAHA – it seems possible that when Philae touched 67P that first time, it gave them both the same charge, and that charge might have repelled Philae…
Not exactly accretion, either. And another argument on my side: the first contact between a planetesimal and a rock WOULD give them the same charge – and thus repulsion.
So, do I accept electrostatic forces as being ADEQUATE? No. I also don’t hear anyone pulling that up as the main accreting force. If some do, point me to them!
All I ever hear is “Well, the loose materials eventually kind of floated together, and eventually their gravity was enough to differentiate the materials.” NOTHING in that discusses the early stages or middle stages. They go direct from “gazillions of small dust particles” in one quantum leap to “now we have planetesimals which gravitationally sweep in more and more material”. They skip OVER the first steps as if, “Well, that is so simple, we don’t have to explain it.”
But no, it isn’t simple. And yes, they DO have to explain it.
You even are saying that yourself. YOU pull up some speculative level of “big enough” and think that saying it makes it so. No offense intended, on that, either! My point is that you can’t just SAY it and walk away, thinking it has been answered.
I can SEE that once the planetesimals got so big then such and such happens. That is not my question. My question is” HOW did they get that big to being metamorphic processes? Dust particles accreting is always the answer, and it just isn’t going to WORK.
And while electrostatics sounds like a feasible speculation on your part, it isn’t solid science without SOMEONE having done work on it. HAS someone? So far, I’ve not seen such work anywhere. And electrostatics is only ONE of the possible forces. Magnetism, perhaps? (I see that as a different animal – and MUCH more probable. And yet, most of the materials are NON-magnetic.)
Escape velocities are SO low and distances are SO far – and electrostatic forces among moving particles is a maelstrom of growing and diminishing attractions AND repulsions. Even 67P’s gravity is NOTHING, and its mass is enough that if it hit Earth we’d all be dead.
Also: Would the attractions be greater than the repulsions? If so, why? And where did the charges come from? And why some are negative and some positive? At least magnets stick together. Same electrostatic charges repel. NOT good for accreting.
Can I ask – did you just think that one up as perhaps the main accretion force? Yes, the electrostatic forces are going to be there. As an engineer I have to ask if the electrostatic forces are ENOUGH.
My answer: I honestly don’t think they are.
— Low relative velocities of objects in the planetary nebula – yes, I WOULD agree, and I’ve always had the thought in my head. Waiting for someone to bring it up. Two questions come to mind:
1.) What ARE the relative velocities? What constitutes low velocity? To materials such as we find in comets and meteors, high velocity is probably as low as 1km/s (…That being 3 times the speed of sound. Take a rock and push it at that 2,200 mph into another rock. See how much accretion happens. These are real materials. If they are remnants of the early solar system, then these are the materials we have to check out their limits. And, trust me, their limits are NOT high enough. Those materials WOULD be shattered or severely, severely stressed by the impact.)
[Corollary: All such objects we see “out there” have been cratered. Craters mean materials have been removed. Ergo, velocities must have been high enough that impact forces exceeded the ultimate strength of surface materials on the planets, moons, planetesimals, asteroids, and comets.] Everywhere we look, we see obliteration. Regoliths? I don’t see anything but dust and boulders lying on surfaces – no fusing into minerals. YES, there are fused minerals underneath – but all later materials just sit there and do nothing. Why isn’t accretion happening NOW? And I’ve questioned how that can happen in that low-gravity, vacuum environment.
2.) If all the “heavy elements” came from supernovas, the escape velocity of supernovas has been pegged to ~10,000 km.sec. Again, a question I’ve asked with no answer from anyone: HOW did those elements come by Our star, Sol, and then magically slow down to less than 75km/sec? Where did the 99.25%+ of their velocity go? That is a HUGE amount of energy to shed. What braking action could possibly have been applied? Where is the heat from the braking? And if something stopped them THAT much, why not all the way? That is a very narrow window – 20 km/s to 70 km/s left out of 10,000 km/s. Why not down to 0 km/s? Why not stop at, say, ~300 km/s instead?
Do these questions even HAVE answers?
So, my answer to THAT is also, NO, I do not accept that the velocities were low enough to accrete. I understand that the velocities were too HIGH to accrete.
I know, you are probably frustrated that your answers didn’t satisfy me.
I consider this a problem that astronomers have swept under the carpet. Why? Because they can’t answer the question of how little strengthless bodies can impact each other – EVEN AT SPEEDS OF LESS THAN 1 METER/second – and then stay together. It doesn’t work in my book.
Yes, Jim, it is about Strengthlessness.
You understand that point. THANK YOU.
But also you could call it gravitylessness – gravity so low that everything wanders off and never comes back. Like Philae almost did to a body 4.2 km long. Not exactly dust.
They worry about this on rotating meteors and comets, you know: If the rotation is too high (and “too high” isn’t VERY high at all), then the meteor slings the regolith off, and with the escape velocity so low, the regolith shouldn’t come back. But somehow it APPEARS that it has. The combination of electrostatics and gravity is sometimes found to be too small, but still, there is the regolith, sitting there and not floating off… They are working on this part…
And then you get Schwassmann-Wachmann out there in the middle of nowhere – no planetary gravitational tides to pull it apart – and then, lo and behold, it comes apart at the seams… strengthlessness?
Would it be possible that it was impacted by a smaller object traveling at approx. the same speed that caused S-W to come apart without a major ka-boom? Just speculatin
Steve,
67P churyumov-Gerasimenko is a comet. By definition they outgass. A lot. Otherwise, the object would have been called an asteroid. The winds are strong enough to strip off big boulders and to fragment the entire comet into smaller chunks, like SW 3. Icebergs can fly off of a comet. So, 700 km/h is not small. It is actually 700-800 km/h, but I forgot how much, so I put a smaller value here. Anyway, once upon a time I needed this data, so I spent a day to derive it. You might try that yourself as an exercise in thermodynamics.
The jets on a comet are actively changing it’s orbital parameters and it’s rotational axis/speed. This is why the cometary motion is unpredictable in a long run – they have their own rocket propulsion.
Regarding the accretion, think rings of Saturn. Many small chunks of ice with very low relative speeds all going coherently in practically perfect circular orbits. Gravity perturbations often form mini moonlets of few meters, which later get shred off by the proximity of Saturn (tides too great). Remove the Saturn, and you would have the conditions in a primordial cloud. Then you would get accretion, because the relative speeds between the particles are practically zero.(What is the difference in orbital speeds around the center of galaxy between two particles separated by a few mm, or cm, presuming identical orbits ?)
The key note is that the accretion occurs for as long as the relative speeds between the particles are low enough. And they would be low for as long as the density of the cloud is high. When the particles accrete into small planetesimals, the game wants to change to a game of ejection and destruction, but it can’t, because a central body forms and sucks in more material from the outside. At the end you have a star and debris, or Jupiter and debris. Mass of the moons of gas giants is always ~1/10,000 of the mass of the gas giant at the center. The moons that still stand are the leftovers from the process of accretion. Like water in a sink, the matter goes inward/downward, until there is nothing more left to flow in, or until the star ignites and blows away the gas.
The exception to this rule is Uranus, which suffered a very traumatic collision later on and lost some of it’s moons.
Your question on what makes an interplanetary gas cloud collapse into a star in the first place has been answered: a mechanical disturbance, a sound if you wish. The wave creates clumps in an otherwise uniform environment.
I agree with you that the harpoons are not a very good idea, but back then they were reasonable choice. The comets were then thought to appear as dirty snowballs. You make preparations based on what you know.
The comets are strengthless, with densities of 400-700 g/ccm. When gases escape, not much is left, but a swiss cheese.
As for the regolith, it does not fly back, but forms on the spot. Think of a solid pebble that gets hit by a few microns large speck of dust. some atoms evaporate away and a hole is left on the surface of a pebble, a bullet hole. The pebble itself remains on the surface because the speck of dust did not have enough energy to destroy it entirely or to kick it off into space. Add more specks over time, and the exposed surface of any rock would resemble a swiss cheese over time up to a depth of a few microns. Then add thermal stresses of several hundred K on a daily base (every few hours), and the surface of any rock would not stand a chance in a long run – it would turn into regolith. Separate particles of regolith acquire static charge due to presence of solar wind, entangle and stick together. This is why all asteroids are dusty. Big impacts are too rare to wipe off the dust.
Jim –
As I last heard it, they are all a-speculatin’, too.
Zoran –
Actually, there area lot of comet-like asteroids out there, and some comets that have characteristics of asteroids. For public consumption, for some reason, they still talk about clear-cut divisions between the two groups. But there are a lot of in-betweeners. A NASA paper all the way back in the 1960s (which I can’t find anymore, dammit) counted 47% of near Earth asteroids with comet-like characteristics.
Zoran –
700-800 km/h = about 0.2 km/sec. Out there, that is SLOW. Earth’s going about 30 km/s, and that seems to be somewhat average.
Zoran –
A lot of assumptions in that scenario. WHY would they all be going on nice easy, essentially parallel orbits? Nothing does now. Things are moving up and down across the ecliptic, things are on elliptical orbits. That “perfectly civilized neighboring orbits” scenario is nice, as long as reality doesn’t intrude. In natural science nothing ever comes without all sorts of variations and variables. NONE of the planets are traveling at the same orbital velocity, so obviously there are wide variations in orbital speeds. Uniforitarianism dictates that “The present is the key to the past.”
Zoran; A question here in regards to Saturn’s rings. If you were to remove Saturn from the picture would the rings have any reason to stay put without the gravitational hold of Saturn?
Zoran –
Pleas have patience with this lengthy comment and rad it through.
I have commented at some length in the past about peridotite and olivine, two materials that are found in carbonaceous chondrites and the Allende meteorite in particular. In fact, these two materials in Allende meteorite are the main things that got me stared on this issue of accretion.
You see, peridotite and olivine are materials from the Earth’s MANTLE. They can ONLY form at high pressure AND at high temperatures. This is a BIG deal. Why? Because, as I first asked, HOW do such materials form in a meteor out in space where such temperatures and pressures do not exist?
Allende fell in the Mexican state of Chiahuahua in 1969 and total known weight is about 2 tons.
Agee et al 1995 “Pressure-temperature phase diagram for the Allende meteorite”. Abstract at http://onlinelibrary.wiley.com/doi/10.1029/95JB00049/abstract
The paper is about lab experiments with high pressure lab equipment to determine directly from the materials within the Allende meteorite the phase diagram – to find the liquidus of the materials (including also garnet). The LIQUIDUS is the highest temperature at which these crystalline materials are completely liquid. As the temperature goes below the liquidus, the crystals begin to form. The paper established a phase diagram to be able to tell what pressure-temperature combinations are necessary to begin crystallizing these materials.
The SOLIDUS is the temp at which ALL of a crystalline material is solid crystal.
The phase change curve shows the liquidus of the olivine from the Allende meteorite to be at 1500°C at 0 Gpa and 1900°C at 14 Gpa (2,000,000 PSI). Above that pressure it turns into garnet.
So, if there is olivine in the Allende meteorite, that 2 tonm chunk of carbonaceous chondrite was at some point subjected to at least 1500°C, or a combination of great pressure and an even higher temperature.
Thus, if there are peridotite and olviine in the Allende meteorite, one has to ask where the temps and pressure came from. The authors discuss it all in terms of planetary differentiation in an accretionary context. And at all points they talk about the depths necessary to produce these materials ON EARTH.
This says that you need a BIG body – bigger than the MOON, whose radius is 1737.5 km – to create the conditions to make these crystalline materials. And that such conditions need to include the formation of an iron core and silicate mantle. Olivine and peridotie are normally discussed as belonging to the deep lithosphere or the upper mantle.
So, my original question was: HOW did those materials get from about 200 km inside a planetary body and out into space?”
Impacts delivering the temps and pressure I’ve ruled out, but you can argue with me about it. My reasons are that the destructive nature of impacts rule this out. There are no shocked materials inside the Allende meteorite. It LOOKS pretty metamorphic, with an ablative crust. But ablation isn’t impact, and ablative crust only run about 3 mm deep.
The main point about accretion is that there are all of these really hard rocks out there (and with regolith on them), all of which obviously did not get metamorphized by deep planetary pressures in order to be hard and crystallized. Yet there they are. They have FAR too little gravity to metamorphize any crystalline materials. But they HAVE them, nevertheless.
At that size, there should just be dustballs, strengthless dustballs, based on their mass-based gravitational forces. But though they have dust ON them, they are solid rocks. Rocks hard enough to withstand the cratering impacts that some (or maybe all) show.
All of this goes to the fundamentals of accretion. HOW are solid rocks formed in space? I don’t know the answer, but the accretion theory glosses over this with a wave of the hand and goes directly to planetesimals – which ALSO cannot make olivine.
If it takes a 6000 km diameter planet to make olviine, something is amiss in the entire accretion theory.
I am surprised that the authors of that paper didn’t even ASK how the olivine got into the Allende meteorite in the first place.
Steve,
You are correct about olivine being formed deep inside a mantle. But, you forget that the history of the solar system involves a lot of collisions. There were many planetary sized planetesimals that did not make it through the early chaos. What you have in the asteroid belt are the survivors of a great battle, most of them full of scars.
For instance, the Psyche asteroid is almost entirely solid iron core of some former planetesimal. That one must have had a mantle, which was entirely blown away by collisions. Plenty of olivine.
Second, Uranus collided with something massive enough to turn it over. There must have been a lot of debris from that collision too, which later scattered around, all over the early solar system.
Only at the outskirts of the solar system you get chondrites to be dominant. One might notice that the meteors also exhibit a lot of pristine appearance of chondrites, but one should also acknowledge that there is a conveyor belt that delivers such objects inward. Scatered disk objects become centaurs, centurs get perturbed into inner solar system and become short period comets, which fragment and eventually become dormant chunks, namely asteroids. Asteroids are further pulverized by occasional collision, fissioned every now and then by YORP, tidally disrupted by terrestrial planets, until only dust remains, which suffers from Poynting-Robertson drag and is ultimately drawn inward into Sun. However, it never arrives there, because at some point it evaporates, becomes incorporated into solar wind and is blown away. This is the system. Sometimes there is more, sometimes less materail in it, but this is how it works.
The reservoirs for incoming material are asteroid belts. Main belt is closer, but it has by far less material than the Kuiper belt. Therefore, in bulk, one can expect that an average NEO is more likely to have come from a Kuiper belt then from the Main belt.
On the other hand, even the objects out in the Kuiper belt do have a lot of rocks from the inner solar system that got scattered to that area. In space nothing is ever destroyed, only recycled and relocated.
So, to summarize, during early accretion, many planets formed, of which only 9 survived. The early planets competed among themselves for the few available orbital slots. Collisions, ejections and accretion were the tools of combat. There are scars all over. Mars is half crater, Earth shed the Moon after a merging collision between Tea and Gea. Uranus got turned aside. Planet between Mars and Jupiter never formed. Only chunks remain. Neptune got Triton, a retrograde moon. Venus was hit by a dwarf planet from Kupier belt. Mercury has lost half of the the crust. There are plenty of olivine sources to choose from. Not to mention that 1% of NEOs are of solid iron – former planetary cores.
Jim,
Yes, the Sun. they will continue to orbit around it on the orbit of Saturn.
Or, outside of the Sun, you have large interstellar molecular gas clouds that typically contain many thousands of solar masses of dust, ice and gas, stretch for many light years and slowly orbit around a Galaxy. These clouds occasionally got pushed and disturbed by supernova blasts. Material from supernova collides with material in the gas cloud and is pushed to some extent by a shockwave. However, the cloud is dense enough to eventually stop the expansion of most of the material from a supernova. A cavity appears on one part of it and an enlarged density on the other. The other, denser parts, collapse due to gravity and form new stars, with material from supernova added in. Collapse of a cloud forms simultaneously many stars, sometimes millions of them, which depends on how much iron you have in the mixture.
With more iron, you get less stars and open clusters. With less iron, you get globular clusters, with many stars packed tightly together.
Steve,
Particles and molecules in a cloud would move in circular orbit if the cloud in question is dense enough. They have to, because any particle that does not would tend to collide with neighboring particles. There would be momentum exchange until an equilibrium is reached. In case of the rings of Saturn, this is quite obviously a circular orbit, followed by all of the particles in there. Only when the accretion advances to the point of scattered planetesimals, the orbits become chaotic. Then you get demolishing collisions, which is why there is iron and olivine on (sm)all space objects.
I correct myself. Kinetic energy of gases depends on temperature and speed depends on mass and energy.
The exact formula is
mv²/2 = 3/2 kT, where
k = 1.38E-23 J/K,
m = 1.67E-27 kg for hydrogen atom.
Multiply m by molecular weight (28 for CO, 44 for CO2), solve by v.
You get m/s, not km/h. My mistake.
Ive mentioned this before olivine is found in the atmospheres of O and Mg rich stars.
As far as high temps go, when a star goes nova its expanding gas cloud is at a very high temps for quite a time and distance.
There was an article recently published about some nova remnant nebula, that is still very hot 5 light years from the source.
Zoran:
You make the case that the early solar system may have had complex interactions. But I think you fail to answer Steve’s main point, can you or anyone name a plausible mechanism that can cause an interior portion of a large body to be disintegrated into small rocks, without leaving shock markers?
David,
Collisions are the only available mechanism for this purpose. One has only to think about a plausible case which leads to what you ask. I’ll give you one here. This one is actually my own hypothesis, so if you talk about it elsewhere, please give me credit for it.
Out there there is an asteroid called Psyche (240x185x145 km), an entirely iron one. Once it was probably a full protoplanet, but the mantle is gone, fully stripped away. The question is how ?
The only answer available is that it lost its mantle in a collision. But, what kind of collision ?
Imagine a cherry and a peach. The cherry is a progenitor of Psyche. It had an iron core (the nut inside), a soft mantle (the pulp), and a thin crust over it. Density of the iron core is 4 times larger than the density of the mantle, which are olivine/pyroxene rocks.
The peach is to represent the planet Mars. It too had an iron core, soft mantle and a thin crust.
The peach and the cherry collided, but their nuts missed each other. It was not a fully centered impact. The impact speed can be reasonably assumed to have been some 15-25 km/s.
Psyche (the cherry) entered at 110°E 45°N (NW of Elysium Mons). The mantles destroyed each other, but the iron core went through, penetrated the Mars like a bullet and went out on the other side, at 120°W 15°S, creating the Tharsis bulge. Parts of Psyche’s mantle that were shielded by the iron core were never shocked and went out too, but were later disintegrated into shards and flew away separately, because Psyche lost its integrity and most of its mass.
(NOTE: This is only a hypothetical scenario, without actual proofs being provided other than a plain simple plausibility. To prove this hypothesis, one would need a computer simulation, and probably a visit to Psyche.)
Or, to broadly answer your question, during a grazing impact, some portions of bodies are totally destroyed, but some portions, those which prevailed, continue to move away practically intact, with their speed of motion only slightly changed. The progenitor bodies get disrupted more or less. Surely, there must have been quite a number of such grazing impacts in the primordial chaos.
Zoran:
Thanks for the response, but I don’t think your hypothetical scenario passes the “simple plausibility” hurdle at all. A massive high velocity collision would not leave the bulk or core of either body in a pristine state.
Zoran; What you are saying, if I get this right, is that as particles and bits and pieces are traveling through space they encounter other particles and with each collision there is a fractional loss of momentum. After a couple of zillion impacts enough inertia has been lost to cause them to be captured by another object and they either incorporate or at least tag along. Please correct me if I’m wrong. In your last post to David you said that the more or less intact portions of the progenitors move away with only slight changes in their speed of motion. Has their direction of movement been altered?
Jim,
Particles have kinetic energy. During imperfect collisions, some of that kinetic energy is turned into thermal energy and emitted away as photons. Photons leave the system and the particles stick together more closely because they lost some of their kinetic energy.
This is why regular matter clumps into stars and planets, while the dark matter does not – it does not have an efficient way to shed off momentum, so it mostly remains in the halos of galaxies. Or so it appears to be. I don’t know much about it.
David,
You are probably correct. However, there is one more mechanism available – tidal disruptions. Two objects pass in close proximity of each other, without collisions. The planet (the larger object) does not feel much, but the passing protoplanet (the much smaller object) might be shredded into pieces if it approaches close enough.
Terrestrial planets can shred a Chiron sized comet without feeling more than a 2-3 times larger tide than normal.
Jupiter can shred anything. Just one such disruptions of a modestly sized protoplanet would have been enough to produce a lot of fairly intact inner material.
Zoran:
Can you supply a reference to an analysis of a Jupiter sized planet breaking up a planet large enough to generate needed pressure to form olivine? Intuitively, you wouldn’t think you could “shred” a body that size due to the gravitational field of the smaller body . And even if it was possible, it seems it would cause a lot of stress and deformation that should be detectable in the remnants.
Regarding matter clumping due to collisions, it is my understanding that for objects 1000 meters diameter, clumping can be modeled computationally, but objects in the 1 to 1000 meter range splatter into smaller objects in the computational models, at least in models of the formation of our solar system, a problem for either the modeling or the formation theory.
I’d like to ask a YD related question. I’ve read about a C-14 cliff occuring at or near the onset of YD, where C-14 dates jump from 11,000 BC to 10,600 BC. If I figured this correctly, that means that some event suddenly added about a 100 kg of C-14 into the atmosphere (4% increase). Is my assessment correct ? Can you speculate about the plausible causes for this sudden buildup ?
David,
Can you tell me a diameter, mass and composition (by layers) of a protoplanet, and I’ll make a calculation myself. On a second thought, I have doubts about shredding a solid iron, but the rocks should be possible. The issue is not the gravity of the body, but its internal integrity – the strength of material. Loose bodies will be shred if they enter within a Roche lobe of a planet, but solid objects would endure more. In that regard, solid iron would survive, but not a liquid core. Objects in an early solar system would have been to young to have formed a solidified core. If, not for anything else, then due to radioactivity.
In case of a rubble pile, when a fairly strengthless body approaches
a planet sufficiently close, gravity of a planet at some distance overwhelms the gravity of a smaller object. (Easy to calculate where.) Then it shreds due to its pieces trying to orbit at different speeds, but only if the internal strength is not large enough to keep it together. Rubble and liquids (lava) do not have such a strength, but solid objects do. Planetoids are never monoliths, so they are expected to shred.
David,
Please forget about my previous post (I probably misused the term ‘Roche lobe’). Nonetheless, I had a thought about the issue, and here is a simple explanation of what happens.
Let us say that Earth herself ventures nearby Jupiter. Radius of Jupiter is 71,880 km, while its mass is 1.9e+27 kg. Earth has a gravity acceleration of 9.81 m/s². Jupiter has the same 9.81 m/s² at a distance of 114,000 km from its center (roughly). This is the distance of weightlessness. If Earth ventures closer the gravity of Jupiter would prevail. All objects would try to fall upward, toward Jupiter, away from Earth, and only the internal strength of material would try to stop them. This strength is limited, because in this case it will have to resist tension, not pressure.
Unattached material (soil, liquids and atmosphere) would instantly fly off. Solid rocks would break at some depth, on which the weight of material (in Jupiter’s gravity field, facing upward) becomes too much to bear. Even solid iron would break into smaller chunks.
The mantle would try to keep rotating simultaneously around the center of the Earth, as enforced by internal strength of material, and around the Jupiter, as enforced by the gravity field. That cannot be. No material can endure that, so everything would break into smaller, mountain sized chunks that have enough internal strength to keep themselves together despite the tension. The closer you go to the surface of Jupiter, the smaller the chunks would be. These chunks would then fly away at different orbital speeds, depending on how far (deep) in the Jupiter’s gravity field they are. From an outsider’s perspective, a string of pearls would form, as with SL 9 comet.
Objects like Ceres or Pallas would be shred at some 1.3 – 1.4 million km distance, while Moon or Callisto would have to go down to 300,000 km to be shred.
Zoran –
Been gone a while…
Starting at your first comment since my last one…
No, collisions are NOT capable of the sustained pressure and temperatures to create olivine. It takes time and slow pressure, to wqork through the various stages of crystallization.
And as I’ve pointed out countless times here before – and became part of my questioning of the accretion theory, is that collisions at the velocities existing are destructive, not constructive. Impacts remove something on the order of 200X or 250X the volume of the impactor. And as that material escapes at velocities above the microscopic escape velocities of the target body, the materials is lost out into space.
One of the reasons for olivine needing planet is what is UNDER it, too – a core and most of a mantle, developed from differentiation.
Zoran – “There were many planetary sized planetesimals that did not make it through the early chaos. What you have in the asteroid belt are the survivors of a great battle, most of them full of scars.”
Yes, that’s the orthodox paradigm. You are repeating it correctly.
But it is not the only hypothesis out there. Van Flandern has page after page of his list of specific reasons to think otherwise. They ignored him. They pretend that none of that is worth responding to. He argues that the asteroids did NOT get formed at the beginning of the solar system but later. And he covers it well. Oh, none of his points agrees with the orthodoxy, but then neither did Copernicus’s points agree with the orthodoxy.
I am not saying that van Flandern is right, but until someone addresses all of his points, I see his points as valid possibilities.
I want you to show me ONE impact on ONE body that did not remove far more material than it accreted. Please.
And regolith on a comet or asteroid doesn’t count – because you can’t show how that material arrived AND STAYED, in the microgravity that the main body possesses. They have enough problems with this now – trying to figure out on some bodies how, with the spin rate, the materials don’t get flung off into space. They use their crowbars, trying to invoke electrostatics. Good luck to them with that one. Another speculative patch upon patch situation, and almost all with little more than suggestions for mechanisms.
Zoran – “…the Psyche asteroid is almost entirely solid iron core of some former planetesimal. That one must have had a mantle, which was entirely blown away by collisions. Plenty of olivine.”
“…must have” doesn’t fly. On a body only 100km in radius, you think a mantle will form? That is hardly enough overburden to pee on, even at the very center, much less part way up to the surface. And 100 km is barely sufficient to get down through our lithosphere to where the olivine is created.
Again, applying the great crowbar of speculation.
“Must have had a mantle” is not evidence, only an application of orthodox thought in a situation where it doesn’t actually fit. It invokes the solution as a path to find the solution. You can’t do that. You can SPECULATE it, but then you have to back it up.
“Second, Uranus collided with something massive enough to turn it over. There must have been a lot of debris from that collision too, which later scattered around, all over the early solar system.”
Now THAT is invoking catastrophism, you know that, right?
But you know that that would mean that asteroids are NOT remnants of the beginning of the solar system. Or at least THAT debris.
And of course, you would put that catastrophe far, far back, in probably the late heavy bombardment period, yes? Because catastrophes don’t happen near our time, right?
BTW, what you just speculated is very close to what van Flandern suggested for many years.
But we can only surmise/speculate on what Uranus’ core/solid body is made up of, since we can only look at its top of atmosphere and gauge by its average density. But what that speculation has as corollaries is that Uranus’ solid body was made of the same materials that the inner planets are made of – and THAT violates the separation of heavies from lights principle that is part and parcel of the planetary nebula/accretion theory (sorry, can’t recall the name of the idea right now…)
Zoran – “Only at the outskirts of the solar system you get chondrites to be dominant. One might notice that the meteors also exhibit a lot of pristine appearance of chondrites, but one should also acknowledge that there is a conveyor belt that delivers such objects inward.”
Ah, orthodoxy again, and this time invoking the magical Oort cloud, which has NO solid evidence showing that it actually exists (unlike Kuiper). Van Flandern explains them all a different way. “The outskirts of the solar system!” A congenial way of putting it.
Without something INTERNAL to the solar system to explain asteroids and comets, it is necessary to INVENT a magical region, with all of the characteristics that one wants or needs to assign the region. And it is conveniently so far away that we can’t see ANYTHING there, so we can say X is there and Y is thre, and they have JUST the right Goldilocks qualities that we WANT them to have.
No.
There is probably 50,000X the solid evidence for the Younger Dryas Impact than there is for the Oort cloud. And the one with all the evidence is the one dismissed by some bad researchers and so the world of astronomers and geologists points to the faulty researchers’ kibitzing and dodge the YDIH bullet. But the Oort cloud, without ONE shred of anything but speculation is accepted far and wide.
What is wrong with this picture?
The Oort cloud only exists by INFERENCE. Sorry, that isn’t good enough for me. The amazing thing is how many levels of further speculation the Oort cloud has produced. All based on a supposition. Smack forehead…
Oh, and like I said, they INFER the qualities that they choose to assign out there in the Oort cloud – “chondrites came from there” – REALLY? And if the orthodox paradigm required tribbles to come from there, too, that would be okay, too.
NO, chondrites DO NOT necessarily come from there. They INVOKE them to come from there, when not ONE chondrite or any other solid evidence puts them there. They NEED them to come from the Oort cloud, or the whole thing comes tumbling down.
The Allende meteorite – HOW did the olivine get inside it? Iron-nickel meteors – how did the iron and nickel melt together in the vastness and cold of space? How did they exclude other materials to such a high extent? With the microgravity out in the Oort cloud region (not necessarily an Oort cloud, but the REGION in space) – HOW did iron and nickel congeal/accrete/melt/aggregate out there before heading sun-ward? The heaviest iron-nickel meteor doesn’t have 1/1000th of th gravity of 67P. Anything hitting an iron rock or nickel rock would bounce off and fly away. Never to come back.
Zoran – “On the other hand, even the objects out in the Kuiper belt do have a lot of rocks from the inner solar system that got scattered to that area. In space nothing is ever destroyed, only recycled and relocated.”
OHH? And how did THIS happen? The “rocks” can’t have had enough velocity to carry them out that far, and IF THEY DID, they would need to be on VERY elliptical orbits, meaning that they might REACH as far as the Kuiper belt at apehelion, but then would return to the inner solar system and their perihelion.
Collisions knocking them off course? Elastic collisions are inefficient, and inelastic collisions don’t exist on the macro scale. Jupiter’s gravity SLINGING them out there? Any empirical evidence off this process happening? Or is it just deductive reasoning? (i.e., THIS is what the situation MUST BE, within the current orthodoxy?)
Reasoning isn’t evidence, in and of itself. It is the attempt to understand the evidence. Reason cannot be invoked except to speculate on what might be the case. The gestalt understanding/orthodoxy – if true – may dictate this and thus – but it can’t be used as evidence a priori. It can only be invoked as a directin finder – pointing to things the then must be tested against reality.
That is the problem with the Oort cloud – and you know it, Zoran: The Oort cloud is not a proven reality. And talking to an engineer and invoking what is only a speculated reality? Ouch!
Like I said, there is a WHOE lot more tangible, forensic evidence of the YD impact event than there is for the Oort cloud.
Give me forensics anytime.
The Kuiper belt? Yep, stuff is out there. Real stuff. A real thing, even if we are only just beginning to learn about it. And, just beginning, I expect there to be MANY moments of shifting of our understanding of what the Kuiper belt is, where it is, and what part it plays.
Zoran – “So, to summarize, during early accretion, many planets formed, of which only 9 survived.”
Uhhhh, NO…
That is your END result. The planets, obviously, are here. YES, planets formed.
I question strongly the idea that accretion was the process. The actual mechanisms available were collisions and ONLY collisions. At ANY velocity above about 0.4 km/sec, collisions are destructive, due to the material strength limitations of the materials being impacted. Very few materials in nature have yield strengths above about 20,000 psi (about 0.15 Gpa). And 20,000 psi is overcome by objects going at 0.5 km/sec. When astronomers talk seriously about “strengthless bodies” in space they are talking about a LOT less cohesion than 0.15 Gpa. They are talking about cohesions on the scale of like 0.001 Gpa.
You can NOT pretend that materials could withstand collisions over 4 billion years ago that they cannot withstand now. That is not scientific, and I believe that you know that.
Deducing that accretion was THE method may seem logical, but where is your evidence of the early bits of the process? DON’T go jumping ahead to planetesimals on me. First explain how the planetesimals were formed from dust particles. That is the GIANT HOLE in the accretion theory.
According to entropy, all those dust particles should have ground each other down to individual molecules. Nothing should have formed.
Invoking the END result as the evidence – WHAT??? And skipping over so many steps in the early process – and ignoring the destructive reality of collisions NOW – Lyell would have your head, since you are not using the present as a clue to the past. IMPACTS ARE DESTRUCTIVE NOW. Just WHY is it that collisions in the past were not? I can’t agree with that, unless you are changing the laws of physics over time. I don’t think I will let you do that.
Pretending that at some magical period in the distant past that impacts were magically not destructive then – it flies in the face of all science.
Zoran – One at a time on that last paragraph…
“Collisions, ejections and accretion were the tools of combat.”
— Accretion is a NON-combative process.
“There are scars all over. Mars is half crater,”
— As in DEstructive. At the known velocity ranges of comets an asteroids, the great majority of the ejecta from the SURFACE of Mars is long gone. as in NOT accreted.
“Earth shed the Moon after a merging collision between Tea and Gea.” Holy crap! Are they selling that as FACT now? OY VEY! PLEASE, tell me – where is the crater on Earth that the Moon came from? (This wasn’t the first laugh out loud question challenging this idea?)
“Uranus got turned aside.”
— Yeah.
“Planet between Mars and Jupiter never formed. Only chunks remain.”
— Look up van Flandern’s work on this…
You are invoking this just after having said that “The early planets competed among themselves for the few available orbital slots”??? WOW. You don’t see any conflict there, huh?
“Neptune got Triton, a retrograde moon.”
— See van Flandern for another possible explanation.
— “Venus was hit by a dwarf planet from Kuiper belt.”
— REALLY? And where is that crater? Oh, they aren’t trying to explain Venus surface temperature by this, are they?
“Mercury has lost half of the the crust.”
— I will accept your word on that.
There are plenty of olivine sources to choose from.”
— Uh, NO. Olivine is NOT a surface material, except where there is enough planet to have a mantle and enough volcanism to bring LOTS of olivine to the surface, where impacts might eject it into space. On Earth to get at big quantities of olivine and THEN metamorphize it into something like the Allende meteor, you’d have to crater minimum of about 80 km deep. And be VERY destructive (not accretive) in the process.
“Not to mention that 1% of NEOs are of solid iron – former planetary cores.”
You DO know that the geologists are only INFERRING iron in the Earth’s core, don’t you? The Earth’s magnetism? Ever heard of the Curie temperature?
[Wiki]: “The temperature of the outer core ranges from 4,300° K (4,030° C)“.
Curie temperature: “For a given ferromagnetic material the long range order abruptly disappears at a certain temperature which is called the Curie temperature for the material. The Curie temperature of iron is about 1043° K. [about 770°C]” http://hyperphysics.phy-astr.gsu.edu/hbase/solids/ferro.html#c3
Ergo, the core is far hotter – about 3,200°C – than the Curie temperature of iron, meaning what?
That the core should have ZERO magnetism.
This is explained away in ways such as this:
Surmising and presuming. Nice science!
Hey, I don’t know the answer, either!…LOL
But dammit, I don’t like science by surmising and presuming and deducing. I want my science to be empirical.
Steve G,
NB: Not enough data for Accretion. Time to fake it until you make it.
CevinQ – “Ive mentioned this before olivine is found in the atmospheres of O and Mg rich stars.
As far as high temps go, when a star goes nova its expanding gas cloud is at a very high temps for quite a time and distance.
There was an article recently published about some nova remnant nebula, that is still very hot 5 light years from the source.”
Thanks.
First one: “Although the peak shift due to the effects of the grain size cannot be ruled out, we suggest that Fe-bearing crystalline olivine explains the observed peak wavelength fairly well. Fe-bearing silicates are commonly found in meteorites and most interplanetary dust particles, which originate from planetesimal-like asteroids. According to studies of meteorites, Fe-bearing silicate must have been formed in asteroidal planetesimals, supporting the scenario that dust grains around Vega-like stars are of planetesimal origin, if the observed 11.44 μm peak is due to Fe-bearing silicates.” http://iopscience.iop.org/1538-4357/610/1/L49
BOLD: It is inferred and interpreted as olivine – with honest caveats, which is to be highly respected.
Italics: Circular reasoning, from what I read. They say that SINCE the olivine is found in meteorites, it must have (SOMEHOW) formed there – and they don’t explain HOW.
Which is my point.
“We report excellent agreement of our observations with predictions based upon this simple model for most stars in our sample, assuming that a mixture of amorphous silicates of radius [approximately equal to or less than] 1 μm is the dominant source of opacity. These observations support the notion that extended disk atmospheres contribute substantially to the mid-infrared flux of young stars.” http://iopscience.iop.org/0004-637X/534/2/838
Abstract only, so forgive me if I conclude too much here. Amorphous silicates are not olivine, which is crystalline, and to MAKE the crystalline form is what takes the pressures.
In addition, μ1 particles are not what is found in meteorites. Full-blown macro-crystals are found, large enough to be seen easily with the naked eye. Getting from amorphous μ1 particles to macro-crystals is a big step.
I WILL accept that something that COULD BECOME olivine MAY BE out there around stars, whether in the atmospheres of the stars or in their own planetary nebulae. What I am finding is vague conclusions. If you know of solid confirmation, rather than suggestions and presumptions, can you point me to them?
Now, I am going to also add this (again): It is widely explained that the heavier elements are formed in super-novas. Not just novas, but super-novas. The escape velocities of super-novas are generally 10,000 km/sec. With no braking in deep space, these materials would pass through the entire solar system in only 3-4 hours. Q: HOW DID THEY SLOW DOWN? “They” being the materials from which the solid planets are made, including the iron in the core. Don’t invoke the gravity of the Sun. Escape velocity from the Sun is only 617.5 km.sec, so in order to CAPTURE that material, that material MUST be traveling UNDER 617.6 km/sec.
The assumption that the heavy elements were vaporized into plasma in super-novae and then blasted across the universe at about 5% of the speed of light and then, just when they passed our neighborhood they decided to slow down and circle the wagons into a nice flat planetary nebula – exactly HOW does that work? ANY PART of it? Goldilocks brakes? Solidification in “just the right way”?
Sorry. Astronomers wanting it to happen a certain way, in a Goldilocks sequence, that is kind of hard to accept.
Something doesn’t add up. None of it should have ever been going slow enough to be trapped by the Sun’s gravity.
Obviously the matter is HERE, so it got here from SOMEWHERE, and it had to be traveling slow enough – so HOW? Their explanation doesn’t hold water. If it was traveling at ~<=70 km/sec, then it could not have come from supernovae. If it came from supernova, it couldn't stop here. You all get ONE of those two – you can't have both.
And iof you invoke shock waves, as someone did some time back, please explain where the shock wave came from, why it would brake materials incoming, and what it did with all that energy – which energy is probably m,ore than the Sun's energy output for a billion years. A solar system's worth of material decelerating from 10,000 km/sec to 70 km/sec is a PILE of energy removed.
One would also need to answer why the material went out in a 360°-360° pattern from ONE supernova and traveled for many parsecs and ended up in a region of about 0.0001° x 0.0001° and STILL had enough matter in that zone to create all of our solar system. The mass of the star exploding would have had to have been millions of times bigger then Sol. Again, Goldilocks thinking – everything JUST RIGHT…
I don't buy it. They are wrong in so many ways… It makes a nice fairy tale, as long as they leave out some pertinent realities. It all sounds good if one can accept that the matter incoming was just sedately wandering around, looking for a place to circle its wagons. I don't.
Steve G,
Here is something to get your juices flowing —
Grand Theft Sedna: how the sun might have stolen a mini-planet
18:00 19 June 2015 by Govert Schilling
http://www.newscientist.com/article/dn27757-grand-theft-sedna-how-the-sun-might-have-stolen-a-miniplanet.html?cmpid=RSS%7CNSNS%7C2012-GLOBAL%7Conline-news#.VYhVRjYw99C
“Our sun is a thief. Over four billion years ago, it stole hundreds of frozen mini-planets from a passing star – and the peculiar planetoid Sedna is one of them.
With its extremely elongated orbit taking it 200 times further from the sun than Neptune every 11,400 years, Sedna has been a mystery ever since its discovery in 2003. Its nearest neighbours, the thousand-plus “ice dwarfs” that populate the Kuiper beltMovie Camera beyond Neptune, are believed to be the frozen remnants of our solar system’s formation.
But Sedna, and a dozen other objects with similarly wonky orbits, are harder to explain. A gravitational kick from a planet in our solar system could never have thrown them into such orbits.
One idea was that Sedna could have been jolted out of place by a passing star, but there was little evidence to back it up.”
And another link to the same story —
http://www.dailymail.co.uk/sciencetech/article-3134488/Is-sun-planet-THIEF-Chaotic-distant-world-outer-solar-result-ancient-cosmic-robbery.html
Steve,
I never said that olivine is created by collisions. It can be excavated. Vesta is an example. It can also be obtained by tidal disruption. Read my last post.
Regarding your view of accreation – please tell me the density and temperatures of the accreting material (gas and particles) in various parts of the early solar system. Then calculate the real orbital velocities of objects involved without either Sun or planets being there to force these to be large.
I believe you are misunderstanding on how accretion really works. It does not involve 2 by 2 particles sticking together. Rather, it involves a great cloud of particles becoming gravitationally bound and not having enough of relative kinetic energy to escape from each other. The particles would try to fell down directly to the weight center and only the centrifugal force would be there to oppose the fall. The cloud then collapses into a vortex around its weight center, which sucks the matter in. 3D cloud is flattened to a plain by dynamic interactions of particles which average their momentum. This increases density. Eventually, you get central star and planets with their moons. When the star lights, accretion stops soon after and then the primordial chaos really begins.
Or, to be more even more specific with an experiment. Suppose that you have a box on ISS, filled with water vapor, but no air. What do you think would happen if the box is cooled down below freezing temperature ? Ice would form, isn’t it. Would the particles stick together as clumps of ice (accrete), condense on the walls of a box or would continue to indefinitely fly madly inside of the box ?
You are misinterpreting the entropy principle. If correctly applied, it says that the temperature of a system would get averaged. And average in space means gradual cooling down to 3 K of temperature, or slightly more. This means formation of ice, not gas. It accretes.
Steve: “With no braking in deep space, these materials would pass through the entire solar system in only 3-4 hours. Q: HOW DID THEY SLOW DOWN?” First, the material starts the travel from a very deep bottom of a gravity. You need 11.2 km/s to escape from Earth. How much do you need to escape from a star ? Or more speciffically, considering that the iron is in the core, which collapses to form a neutron star or a black hole, how much iron really manages to escape and with what velocity ? A lot of the initial kinetic energy would be lost for climbing away.
Second, massive stars that explode as supernovas are often surrounded with a lot of interstellar gas. What can stop a few solar mass of matter escaping ? How about millions of solar masses of gas that stretch for light years in every direction. The intrstellar space is not entirely empty. In fact it is often very dense. The solar system currently goes through an area cleared by some ancient supernova explosion, so the surrounding vacuum is very thin. But, in a molecular cloud it is many orders of magnitude thicker. For instance, blow up the Sun to a diameter of 2 light years and check how dense the gas would be – the answer might surprise you, as there would be still about 300 million atoms per cubic meter. Not exactly a hard vacuum, isn’t it ? Welcome to an interstellar gas cloud. What is the chance of a particle to pass go through that for hundreds of light years without collision ?
Third, there are many supernovas, not just one, that contribute to the general mixture of interstellar clouds.
Fourth, do you know what is the iron content of the Sun ? Less than 0.2% if I recall it correctly (Icould be wrong – please check.) The Sun is actually rich in metal, an atypical star. Others have by far less, some of them orders of magnitudes less heavy elements. By the way into that 0.2% go all the elements apart from H and He. How much iron a supernova produces ? Stars that explode as supernovas are 10+ solar masses in weight. Most of the escaping gas is still hydrogen, but there is also a hefty amount of iron, carnon, oxygen and neon. At least 1.4 solar masses of iron collapses into a neutron star or a black hole. The rest, whatever the amount is, escapes. Enough of material for thousands of stars to form with solar like metallicity if all of that gas is stopped by the surrounding interstellar gases.
Fifth, the SN explosions create shock waves in the surrounding gas and produce bubbles, like the one that the Sun is curently in. For a bubble to form, some energy must be deposited, which means some of the escaping gas undergoes collisions with the interstellar gas and is slowed down.
Any impact on a planet is an accreting one, even today. SL 9 on Jupiter, Chelyabinsk on Earth. Prove me wrong if you can.
Van Flanders ? Elaborate please, at least by saying the name of his paper, or what he proposed.
I already explained the presence of regolith. It is being created in situ from rocks, not accreted.
Steve,
If Psyche is not an exposed core of a much larger protoplanet that at some point was entirely disintegrated one way or another, then you please explain its presence as a chunk of pure iron!
I don’t know when the Uranus turned around, but I am certain that asteroids have nothing to do with it. It collided with something of several Earth masses. This is the only reasonable way known to me to explain its tilt.
By the outskirts of the solar system, I meant the edge of it, wherever that was, not the Oort cloud. That, I never mentioned. I never assigned anything to it. You are misinterpreting my words. The only evidence for the existence of the Oort cloud are the long period comets. However, let me remind you that technically the gravitational border of the solar system goes far beyond Kuiper belt. No one knows what lies in there, but no one can prove that the area is empty. However, there are hints that the Sun might have a companion somewhere there in form of a distant Jupiter sized planet, a failed brown dwarf. It is only speculation at this point, so I won’t discuss it.
I said that the mayor reservoirs of debris in the solar system are its 2 belts – the Main and the Kuiper belt. NEOs come from there and dynamically do not last very long in the inner solar system, 10 Ma on average. Every few hundred thousand years, they fission due to YORP effect, loosing ~6% of their mass on every fission. this is why 15% of all NEOs are binaries or multiples. The satellites of NEOs tend to fly away eventually due to gravitational influences of terrestrial planets.
Now we have 8 planets and a few dwarfs. What do you think was the situation early on ? How many planetesimals was there ? 1,000 ? 10,000 ? What happened to them ? The only answer – ejected by gravitational slings, disintegrated by tidal disruptions or merged with other mayor objects, including with the Sun itself. For slinging, you have Centaurs as evidence. None of their orbits is long term stable. for instance, it was found that Chiron has 12% chance of becoming a NEO. Or it may be thrown entirely out of the solar system. The exact outcome is chaotic and thus unpredictable. Same applies to other Centaurs. They are only in transit.
A planet between the Mars and Jupiter actually did form, the dwarf planet Ceres. Everything else in the Main Belt has less mass altogether. Few of the other large Main Belt asteroids are itself protoplanets, but almost all of the small ones are just debris.
Objects in different parts of the solar system have a different istopic composition, as was detected by spectral analysis. This is how we know that Venus collided with a dwarf planet from KB – by the isotopes of Ar in its atmosphere, and by her having excess of nitrogen. You don’t have a crater, because Venus has a young surface. The same is true with Gea/Tea collision. Besides, you can’t make a crater in a ball of liquid. Even today the solid crust on both Earth and Venus is merely skin deep in comparison with the size of these planets.
However, I will point out that the Moon is 6% of Earth’s mass and is made of the same material. YORP fissions typically shed off 6% of material. Moon fissioned either because the angular momentum of Earth became too high after a merger, or because settling of iron into Earth’s core caused it to rotate too fast. This is my unorthodox view. The orthodox view is that the Moon formed out of a ring created by a merger of Gea/Tea. The difference in these views is in the amount of angular momentum.
You mention the Curie temperature. Why do you think that you need a pemanent magnet to create a magnetic field ? You only need a flow of electric current. The copper is not magnetic, yet it produces a magnetic field when a current flows through a copper wire. The currents would flow if there is a conductor available. Iron for instance. Saying that the iron is not in the core is nonsense. There are plenty ofevidence in that regard – the density of our planet, behaviour of seismic waves, natural abundance of iron in space in general, the existence of Earth’s magnetic field, the expected settling of denser elements into the core of a liquid body, the existence of iron meteorites to serve as evidence from other places. What is your evidence against it ?
Finally, you wanted forensics about YD. Well, here we are discussing space issues at large, but nothing about the actual article of Davias and Harris. There is plenty of things that can be discussed there. So, if I am not asking too much, can we please drop for a while the discussion of accretion et al. and go back to topic ? Thank you.
Trent –
“Our sun is a thief. Over four billion years ago, it stole hundreds of frozen mini-planets from a passing star…”
Oh, GAWD, the wandering star (without any evidence) fantasy again…
Like the galaxy doesn’t have NAY organization to it. The spiral arms and the force of gravity don’t have ANYTHING to do with any of it. I dare say that if a star had come that close all of the planets would have REALLY elliptical orbits, plus much more inclined orbits.
The operative words in such garbage science articles it the words “might have”.
Guys, I respect good science as much as the next guy. But when it is bad science, it pisses me off.
Speculation is not science.
Speculation is what existed BEFORE science.
Zoran – “I never said that olivine is created by collisions. It can be excavated. Vesta is an example. It can also be obtained by tidal disruption. Read my last post.”
Your last post was the one about Earth getting close to Jupiter. A lot of that isn’t going to happen the way you say. Not thatit is here nor there, because it isn’t going to happen.
At the point where the acceleration due to gravity is equal, loose stuff will not go anywhere. As Earth gets closer, they would FLOAT off. At the ponint where Jupiter’s gravity is dounle Earth’s 9.81 m/s^2 they would have an equal acceleration toward Jupiter as they do here – 9.81 m/s^2. And at that point none of it would be dismanlting itself, because why would it, when it isn’t being shredded here under that acceleration. Even when it got to be triple the 9.81, 99%of things would be okay, because that is only 2Gs of acceleration. Humans can stand how many Gs? Momentarily humans have survived 50 Gs and more. That is 9.81 x 50 = 490 m/s^2. And they didn’t shred. They were, in fact, okay, except for some injuries – which healed.
ASTM A-36 mild structural steels would need to exceed a tensile force above 66,000 psi before beginning to crack – but the majority of the matter in a steel object would stay together, even if parts broke off. Rocks would need something less, and that would vary a lot. All sorts of things would be fine under 50 Gs of acceleration. Since your “balancing point” of 114,000 km is only about 4 Jupiter radii, most things on Earth would stay intact quite a bit closer to Jupiter than that.
Do not go by comets breaking up. Many of them are at or close to “strengthless bodies”, and tidal forces affect them much more easily. After all, how much force does it take to pull something off a surface if its effective weight is measure in a few grams? Tidal forces applied to loose debris or fluids are not the same things as forces needed to tear apart solids. You are talking MAGNITUDES more force/acceleration. It’s kind of like a thing called “angle of repose“. That is quantified values of angles of the slopes of piles of loose materials, such as coal, gravel, etc. The gravel or coal will flow downhill if the slope exceeds the angle of repose – but the individual particles don’t shred themselves.
Actually, the surface gravity of Jupiter is only 24.79 m/s^2, so that is only about 2.52 Gs. For all intents and purposes, NO SOLID THING on Earth would shred before Earth hit the surface of Jupiter.
Zoran – “I never said that olivine is created by collisions. It can be excavated. Vesta is an example. It can also be obtained by tidal disruption. Read my last post.”
You talk about olivine being excavated. Got it.
But, to EXIST under the surface so that it CAN be excavated, olivine needs a planet 6000 km in diameter. One WITH a core, if I understand the literature correctly. And it needs to be formed ~100 km under the surface. So you’d need a HELL of an impactor just to get the first bits of olivine excavated. Maybe a 10-15 km impactor – easily enough to kill everything on Earth.
You don’t say why Vesta is an example.
Zorqn –
And once you get the olivine excavated out of the Earth, pray tell, how do you get it then INSIDE the rock matrix of the Allende meteorite?
It all came out in one chunk?
But it is as old as Earth.
Also, everything then, in the same neighborhood, was going the same speed, according to you. So such impacts would be impossible, according to you.
See the dilemma? The logic goes around in circles. You need impacts of high velocity to excavate the olivine, but you say you can’t HAVE impacts at high velocity.
Oh, I DO agree that olivine was somehow excavated. Don’t get me wrong on that. But HOW? And when? And just what body did it get excavated from?
…
Let’s say that the escape velocity ratio of Philae-to-67P is true. It isn’t but let’s ballpark it. It came in at 1.0 m/s and went out at 0.38 m/sec. A ratio of 0.38:1.
Let’s say that an impactor excavated the Allende meteorite from the Earth. Earth’s escape velocity is 10.2 km/sec. Let’s then say that Allende as ejecta was going out at 11.0 km/sec. Then the impactor had to have been coming in at about 29 km/sec, delta-V. That is entirely within the realm of known solar system bodies, so such a thing MIGHT be possible, if our approximation was reasonably correct.
Now, at the same time, Allende is the biggest meteorite ever known, so to throw out a chunk that big, the impactor had to be very large.
But it also had to hit AFTER the Earth was already differentiated into lighter materials near the surface and heavier toward the center. That is the when.
But that is not “the earliest stages of the solar system”, as is commonly asserted all over the place in popular science articles about comets and asteroids. The oldest rocks found on Earth are 3.9 billion years old. The Earth is asserted to be 4.6 billion years old. Somewhere in that 700 million years is the time when differentiation was done. We can probably guess that differentiation was finished by about 500 million years – about 4.1 billion years ago. But that is still about 10% after the Earth FORMED in a liquid state. Liquid is the state that geologists claim at 4.6 Bya. And if the Earth were molten then, one would guess that the rest of the materials in the solar system also were.
So, did all of it accrete while it was molten? That is a thought, isn’t it?
One site says, “The heat had been generated by the repeated high speed collisions of much smaller bodies of space rocks that continually clumped together as they collided to form this planet.” http://www.extremescience.com/earth.htm
So, the smaller things were solid rocks, and so was the Earth – until enough rocks hit it. And then, “As the collisions tapered off the earth began to cool, forming a thin crust on its surface.” [same source]
Amazingly, the impacts CAUSED the melting of the Earth ALL THE WAY DOWN TO THE CENTER. Really? Do we see heating of any planets today from impacts? NO. Not even on their surfaces. Nobody else sees ANY problems with any of this?
I GUARANTEE that no impacts were going to CAUSE melting right down to the center of the Earth. Such an idea is ludicrous. Seriously, these materials do not conduct heat that well – silicates and ferrous materials. The heat from a single impact would travel METERS, perhaps, but not kilometers. Especially not thousands of kilometers.
And actual scientists accept this? That is really sad.
Zoran – “I believe you are misunderstanding on how accretion really works. It does not involve 2 by 2 particles sticking together. Rather, it involves a great cloud of particles becoming gravitationally bound and not having enough of relative kinetic energy to escape from each other.”
You really and truly believe that? Calling it a cloud makes it all Goldilocks? And they magically stick together? And what do you base your “not having enough relative kinetic energy” on? Someone told you?
You ARE allowed to not swallow everything whole, if you see reasons why something doesn’t look feasible.
That those dust PARTICLES have enough gravity to hold each other together and migrate toward each other? PLEASE, do one of your gravity calcs on two particles 10 meters apart. 1 gram each. Hell, 1 kg each. I don’t care HOW many there are, combined in cloud, the interactions ARE still one-to-one. You can’t suspend Newton’s gravitational formula by asserting a cloud, dude.
After you’ve done that, figure out the velocity of each at impact and the rebound – at let’s say the 38% of Philae. And then compare that to the escape velocity of one of those 1 kg particles. If Vrebound > Vescape, you got nothing.
Then explain to me where those particles came from. From supernovae? I don’t know about that! I mean, it’s the only possible source anyone has come up with, but with that 10,000 km/sec escape velocity, WOW does that bring up a whole new can of worms. Sans an escape velocity over about 100 km/sec, I would not quibble about it. But 10 THOUSAND km/sec???!!! Yoy!
At http://geology.com/minerals/olivine.shtml I ran across this description:
I was considerably shocked to read on such an orthodox website the bit about “a rocky planet that used to occupy an orbit between Mars and Jupiter”. Tom van Flandern would be pleased.
ALL of the descriptions in this section of the page discuss olivine coming from the mantle – of a planet or of an asteroid. This is exactly what I have pointed out here. They totally understand that the olivine HAD TO come from the same sort of depth of a “differentiated” body of considerable size. Differentiation does not happen until a body has reached a certain point.
Now, what they DO NOT talk about is HOW the olivine got from deep inside a differentiated planet/asteroid and out into space on an Earth-intersecting orbit.
It is patently obvious (to me, anyway) that if olivine-bearing meteors were “removed” from the depths of an asteroid or planet, then OTHER materials from less deep portions of the planet or asteroid must also have been removed in the process.
This was my first exposure to pallasite. I highly recommend a look at https://en.wikipedia.org/wiki/Pallasite. And images of pallasites at https://www.google.com/search?q=pallasite&espv=2&biw=1568&bih=846&site=webhp&tbm=isch&tbo=u&source=univ&sa=X&ei=w_OKVdrRI8eloQSX7ISQCg&ved=0CCgQsAQ
Those things are BEAUTIFUL.
If you look at the matrix in images of pallasites, the bluish material between the crystals is IRON. The cm-sized crystals are the olivine. It makes sense to me for them to surmise that pallasites came from the mantle-core boundary of a differentiated (large) body, because olivine is the first material to crystallize out as a volume of molten magma cools. I.e., olivine crystallizes at a higher temperature than the other materials like gabbro and basalt. The matrix of these pallasites is roughly half iron and half olivine – so thinking it came from the boundary between the mantle and iron core makes plenty of logical sense.
So, if pallasites came from deep within a large differentiated body, then that makes it all the more reasonable that the Allende meteorite did, too. No guarantee, but it seems possible.
All of this seems to confirm my thinking about where the olivine in meteors comes from – that the olivine did NOT form out in space. The corollary to that thinking is to ask seriously how the olivine came to be both removed from deep inside large differentiated bodies AND how the olivine got out into space.
Hahaha – but now I might be talking about pallasites more than about Allende.
CevinQ –
Here is how the http://geology.com/minerals/olivine.shtml page describes the olivine around the young star:
Again, the olivine is interpreted to not have formed in space, but in this space on the surface of the young star.
I would like to ask them how the olivine came to BE on the surface of the star. Olivine crystallizes at about 2000°C, and the surface of even Class M stars (the coldest stars) bottoms out at about 3,000°C. Okay, they talked about “amorphous olivine”, so perhaps they saw that the olivine could not be crystallized yet.
At least in this they propose a mechanism for transporting the olivine out into space. I probably am doubtful, though, of “strong air currents” on the surface of a star, young or old. I hope they come up with a better one. With the gravity that must be present, how HIGH could such “air currents” go, anyway? If the gravity is Earth-like, no air currents are going to lift FeSio2 or MgSi02 blobs up off the surface. Tornado-like winds? One would think that a bit unlikely, and even if it was, what other materials are there? Only pre-crystalline olivine? It would be molten and would shear/SHRED in tornado winds. I would envision prominences as more likely mechanisms, but that is just a wild guess.
Steve; You got me again! I was reading the link about Olivine and when I saw the pics of olivine on a stony meteorite and it looks exactly like the spec on my meteormaybe. I’ve contacted the Adler Planetarium and the Field Museum to see if anyone there might be able to confirm my find. Wish me luck.
Steve,
The Moon has 1.2% of Earth’s mass and it does exert tides on Earth from where it is, even though the gravity acceleration from the Moon here is only 33 µm/s². Jupiter is 25860 times more massive and if the distance to such object is to be set as 1/3 as that to the Moon, tell me what would be the level of tides ? Under a 300,000 times larger tidal stress ? Do you still think that we would be fine ? Right.
The Sun is a cloud of 1.6 million km across. Every particle is for itself on one-on-one interactions., according to you. So how come that it would collapse into an Earth sized white dwarf when the fusion ceased ? The reason is the same that caused a cloud of few light years across, that the Sun once was, to collapse into a star – a tiny object in comparison with the initial size. Gravity.
Vesta has a crater that exposed the mantle. There is a separate class of olivine containing asteroids that are called Vestoids (class V). Because they come from Vesta. Find the picture of Vesta on the internet.
Class J in asteroid classification also comes from Vesta. this one is from the deeper layer than class V and contains particularly lot of olivine and pyroxene minerals.
10,000 km/s is only 17x more than the speed of solar wind, and the solar wind gets stopped at Voyager distance, more or less. Please also note that we are talking here about charged particles. They would not travel in a straight line, but would follow around the magnetic field lines that they encounter on their way until the inevitable collisions with the other particles slow them down, all the way to the level of cosmic background radiation of 3 K (speed is a measure of temperature). This can take a lot of time, but the Universe is patient by default.
>>10,000 km/s is only 17x more than the speed of solar wind, and the solar wind gets
>>stopped at Voyager distance, more or less.
Ahem…KINETIC ENERGY = Mass time velocity {SQUARED}
Mass for mass we are looking at 289 times the kinetic energy, 2.29-ish orders of magnitude.
Order of Magnitude -mean things-.
Game, set, and match to Steve Garcia.
Zoran –
Why are you talking about ocean tides? Fluids with ultra-low shear strengths are not the issue. You had talked about Earth shredding apart if it got within that 114000 km of Jupiter. I pointed out that even on the surface of Jupiter only very weak solid objects on Earth would have a problem, because Jupiter;s surface gravity is less than 3 Gs. Yes, water would flow to Jupiter. So what? If Earth got anywhere near Jupiter all life would be gone anyway, from the cold, if nothing else.
Zoran –
Talking about the Sun and each particle there being affected by all the others is true – in close proximity – as long as you disregard distance. But I am not going to let you get away with disregarding distance. The volume of space in a nebula is VASTLY more than within the Sun, even if the Sun is 1.6 x 10^6 km across. Now take a diameter of, say, Jupiter’s orbit at 7.783 x 10^8, and let’s “cram” all the mass of the solar system into that radius – including the Sun’s. Even taking a height of a disk only as tall as the Sun (instead of a sphere), the volume is about 2.65/1.41 million times the volume (1.876 million). And that is only out as far as Jupiter. Now, the Sun is 713.2 times the mass of all of the rest of the Solar system, so the density out there on average is 713.2 x 2.65 / 1.41 times LESS as the Sun = 1.3 BILLION times less than the Sun. And, as I said, that is if we only put the mass inside the orbit of Jupiter.
1.3 billion is a lot. 9 magnitudes.
The particles out there are not helping each other, with each one in a volume 713 billion times greater than inside the Sun. Each particle occupies on average a cube 1100 times bigger on each side. At 1100 times the distance, the gravitational force is about 1.2 million times weaker between any particle and those above it, next to it, or below it. And the HELP each particle gets from the next particles over? 4 times less – about 4.5 million times less help.
And how much would such gravitational diminishing affect particles not standing still, relative to one another?
Zoran –
(Taking these one point at a time…)
And then you want to thin this all out by going out to “a couple of light-years across”?
REALLY? With that same mass?
1 light-year = 9.46053e12 km. Times 2. Versus 7.783e8 km for Jupiter…
Let”s keep it at the same disk height as the Sun – 1.392e6.
The volume then goes to 3.91e32 cubic km.
The density is then 2.77e14 times LESS than inside the Sun. Or 1.5e8 times LESS than the density of all of the solar system’s mass was evenly spread out inside the orbit of Jupiter. 150 million times less.
And you think that in that all-but-total-vacuum one particle is going to help other particles? They are going to be 528 times FARTHER away from each other than even the thinness when all of it was inside Jupiter’s orbit. That means that the NEXT particle is helping with (double the 528)^2, or 1/3.5 millionths as much force as the first on next to any particle.
And you still haven’t addressed how that material came from supernovae at 10,000 km/sec and slowed down to 70 km/sec and less. No braking in space. No friction. A shock wave? Coming from where? And of what is the shock wave comprised? Photons? Yeah, right.
Gimme something solid to go on here, please. Not just parroting of what they told you in Astronomy class.
Zoran –
I am working separately on the Vesta thing. You aren’t going to like what I found.
I didn’t see your comment about the 10,000 km/sec, ntil I’d commented that you hadn’t addressed it. My bad. But on your comment, I gotta respond:
“10,000 km/s is only 17x more than the speed of solar wind, and the solar wind gets stopped at Voyager distance, more or less. Please also note that we are talking here about charged particles. They would not travel in a straight line, but would follow around the magnetic field lines that they encounter on their way until the inevitable collisions with the other particles slow them down, all the way to the level of cosmic background radiation of 3 K (speed is a measure of temperature). This can take a lot of time, but the Universe is patient by default.”
ONLY 17 times more? ONLY??? 1/17th equals 5.88%. What happened to the other 94% of the velocity? And to boot, we aren’t talking about SUN-generated particles, which we know where they come from and why. We are talking about INCOMING particles that have to have slowed down – not to solar wind velocities – but to 70 km/sec and less. And THAT isn’t a 94% reduction in velocity, it is a 99.3% reduction. Stuff that could cross the entire orbit of Neptune in 4 hours – and Neptune takes HOW many years to circle from one side to the other? It takes 82+ YEARS to do that (on an elliptical orbit).
And talking about “magnetic lines” of flux, dude, you invoke stuff that infers other things, and in magically sufficient strengths. There are magnetic lines of force all around me right now, and they aren’t directing many particles at all. Why? They aren’t strong enough.
In addition, to “encounter magnetic fields along their way” there has to BE a magnetic field, and any magnetic field takes electric current flow – as in electrons flowing in an organized way, and from molecule to molecule. That is what electricity is. HERE in the Solar System – before anything is here, you are invoking ELECTRONS?? Moving from WHAT molecules to what molecules? Since no matter was here before the supernovae particles magically got off the bus here, WHAT molecules? Are they magical ones? From another universe, stopped in for a while? Where did they come from?
And “the inevitable collisions with other particles” – again, invoking magical things. Please explain what makes such events inevitable?
“This can take a lot of time, but the Universe is patient by default.” The invocation of the magical “unlimited time” solution to everything that can’t be explained by evidence and logic – just like Christians invoke “It’s God’s will”, or “Who is to know the mind of God?”, or “God is all powerful”. And did you ACTUALLY SAY OUT LOUD, “the Universe is patient by default”?
I will give you a take back on that one…
Trent –
THANK YOU, for putting that up. I was going to mention the velocity squared thing, too, but am GLAD you caught that!
My point exactly – where did all that ENERGY go? Being as they were out in the vacuum space, if they SHED that energy, it had to be radiated as EM. If so, it could account for the heat that is thought to have existed. They all would have heated each other radiantly.
But starting WITH the heat first isn’t science. Science is about explaining proceses. So HOW would they have slowed down so much?
And it is not the speed of solar wind. Bringing that into this was bogus. It is the 70 km/sec (conservatively) versus the 10,000 km/sec.
So it is not 17 squared. It is 10,000^2/70^2 = 20,408 times as much energy before and after. That is FOUR magnitudes.
For the more normal solar system velocity of 30 km/sec, the result is 111,111 times as much energy as before – a FIVE magnitude reduction.
Steve,
Tides affect the crust too, for a few cm – because most of the Earth is not particularly solid (lava).
Particles from SN are what we call cosmic rays – very energetic indeed. The record observed is about 100 N per single particle.These particles were not that fast initially, but were additionally accelerated by magnetic fields that they encountered over time, stellar magnetic fields. Sun has a magnetic field that extends all the way to Voyagers and is proved to be able to influence some (less energetic) cosmic rays. Do you really think that the space is empty ?
The particles from cosmic rays are stopped when they hit matter. You asked where the energy goes ? Energy converts to matter in all high energy particle collisions. You get all sorts of particles as a result, aside from photons. Well, those that you have enough energy to form. However, this is not my area of expertise.
The question is what are the chances for a particle ejected from a SN to hit another particle while it is still within the Galaxy ? Note that the space is not 100% transparent, especially within the plane of Galaxy. Also, take a look at star eta Carinae. Such massive stars often eject several solar masses of their mass in a series of eruptions. The blast of SN would chase and catch that ejected matter, while it still represents a fairly thick slowly expanding wall of matter, surrounding the parent star.So, tell me what is gonna happen there ? Or better yet, tell me where do you think the iron came from, if not from other stars ?
Finally, the sun is 4.5 Ga old. Universe is about 13 Ga. The difference makes a lot of time for ejected particles to be stopped.
Steve,
You said that there is no braking in space, nor friction. This is true for matter, but not for atoms. Atoms can absorb and emit photons, which are abundant in space. Each time when they do that, their momentum is changed significantly.
Further, atoms tend to cool down to the surrounding temperature, which mean that they would emit photons at the expense of their own kinetic energy until they reach the low bottom of cosmic background radiation at 3 K. Then their speed would be only few tens of m/s. If they form molecules, the speed would be even lesser.
Specs of dust, if not already present, might form from magnetic atoms, like Nd, attracting each other from distance. These would have very low velocities when cooled to 3 K. Yes, they would still move around the Galaxy at some great speed, but relative to each other, their speeds would be slow. (On the same way, you are moving around the Sun at 30 km/s, but relative to your computer, very little, depending on how fast you type.)
“Most scientists believe that pallasites were formed at the mantle-core boundary of differentiated asteroidal parent bodies. Nowadays the formation of pallasites is a subject of discussion. Different ideas can be found in papers by Scott, Buseck, Norton, Miyamoto and much more. Because of much work currently is in progress, no firm conclusions could be drawn on the origin of these enigmatic meteorites.”
http://www.geo.tu-freiberg.de/Hauptseminar/2009/Lena_Boeck.pdf
The point of talking about tides and Jupiter is because someone asked about it – how to shred an olivine containing object without shock.
However, even the solid iron would fell apart if big enough. The very reason for this is that the object would be burdened by a fairly static TENSION of weight, not with acceleration pressure, as you hastily assumed. There is a great difference.
When you accelerate an object on Earth it experiences inertia. This is what you discussed, but it is not the point. Better express the gravity acceleration as N/kg and then ask how many kg your object has. Then calculate its weight. The weight on Earth is pressuring everything toward the center. Objects tolerate pressure well. But, in this case, the weight would be stretching the object. TENSION. Big difference.
If you have a solid rotating ball of iron, it would tear at a depth where the tensile strength of iron is exceeded by the weight of the material above (vector of force pointing out of the ball’s center, not in). This issue is what those dreaming about a space elevator have to deal with. Breaking height for Al is 10.6 km, for Ti 5 km, and for iron even less than that. This means that at a depth of ~3 km the ball of iron would tear if burdened with 1 G outward. (OK, one has to calculate the exact load distribution over the volume of a ball to get the clear picture of what would tear and when, but the things would definitely tear if they are tensioned and have a size of many km. Small objects endure, but not the big ones.)
Zoran –
About cosmic rays being the heavy element particles created in supernovae,
[wiki]: “Of primary cosmic rays, which originate outside of Earth’s atmosphere, about 99% are the nuclei (stripped of their electron shells) of well-known atoms, and about 1% are solitary electrons (similar to beta particles). Of the nuclei, about 90% are simple protons, i. e. hydrogen nuclei; 9% are alpha particles, and 1% are the nuclei of heavier elements, called HZE ions.[10] A very small fraction are stable particles of antimatter, such as positrons or antiprotons. The precise nature of this remaining fraction is an area of active research. An active search from Earth orbit for anti-alpha particles has failed to detect them.”
So, what are these HZE ions?
[Wiki]: “HZE ions are the high-energy nuclei component of galactic cosmic rays (GCRs) which have an electric charge greater than +2. HZE ions include the nuclei of all elements heavier than hydrogen (which has a +1 charge) and helium (which has a +2 charge). Each HZE ion consists of a nucleus with no orbiting electrons, meaning that the charge on the ion is the same as the atomic number of the nucleus.
HZE ions are rare compared to protons, for example, composing only 1% of GCRs versus 85% for protons.[1] HZE ions, like other GCRs, travel near the speed of light. Their source is likely to be supernova explosions.[2] The abbreviation “HZE” comes from high (H) atomic number (Z) and energy (E).”
Focus on the bold sentences. The heavy atomic number and energy particles are, indeed, the nuclei of about 1% of the output of supernovae, BUT:
We have an even BIGGER problem if they are traveling near the speed of light than if they are only going 10,000 km/sec, don’t we? Decelerating from nearly 186,000 km/sec is a lot more erengy to lose than from only 10,000 km/sec.
You got some ‘splainin’ to do, Lucy…
Zoran – “The particles from cosmic rays are stopped when they hit matter. You asked where the energy goes ?”
Zoran, you DO know, don’t you, that we are talking about nothing being here, and then the heavy elements (HZE ions if you must) arriving. What matter is here to stop them?
I would seriously object to the concept “are stopped when they hit matter”. In the atom smashers they have them wound up at the highest energy levels they can manage and hit them head on, and still almost never hit – and even then the particles are not stopped, even in their destruction into the galaxy of subatomic particles.
So this “almost never hitting” cannot then be a part of the slowdown, because at 10,000 km.sec the particles are only within the orbit of Neptune for about 4 hours, and then they never come again. And in that four hours, they are supposed to have impacted enough particles here (where did they come from in the first place?) in order to stay here? Or this is supposed to have happened many, many times in this ONE SPOT in the galaxy (plus other spots where other suns appeared)? Isn’t that a bit Goldilocks?
And nothing in that sentence says where the energy goes. At near the speed of light, along with the dilation of time, the mass goes nearly to infinity (according to Relativity), and the energy levels should be far greater than “through the roof”.
You DO realize that there is a growing population of cosmologists and astrophysicists who are throwing up their hands at all of this ideas that they have no possible means of ever proving empirically. The Emperor’s New Clothes and all that. It’s like MS Windows – patches upon patches upon patches, ad infinitum. When someone recognizes a problem with the patched-up gestalt, they just ad hoc another patch and throw it on the pile. The empiricists just shake their heads and walk off, mumbling.
Zoran – “The question is what are the chances for a particle ejected from a SN to hit another particle while it is still within the Galaxy ?”
Yeah, DU-UH.
…..”Note that the space is not 100% transparent, especially within the plane of Galaxy.”
And even in proton colliders, they have focused dense groups of protons that they send around in opposite directions, and the density there many magnitudes higher than “out in space”. And hardly any of those particles actually hit each other. And you are asking us to believe that in four hours (at 10,000 km/s) or less (if nearly 186,000 km/s) the material from supernovae are going to miraculously hit something? You are dreaming.
…..”Also, take a look at star eta Carinae. Such massive stars often eject several solar masses of their mass in a series of eruptions. The blast of SN would chase and catch that ejected matter, while it still represents a fairly thick slowly expanding wall of matter, surrounding the parent star.”
You’ve got to be kidding. The two events are going to coincide? That is a fantasy speculation and nothing more. That is like asking who would win a fight between Superman and Mighty Mouse.
Zoran – …..”You said that there is no braking in space, nor friction. This is true for matter, but not for atoms”
Excuse me, but when did atoms stop being matter?
…..”Atoms can absorb and emit photons, which are abundant in space. Each time when they do that, their momentum is changed significantly.”
Fine, now how many of these photons does it take to slow down atoms/HZE ions from nearly 186,000 km/s to <70 km/s? The momentum loss is about 170,000^2 / 70^2 – about a 6 million-fold reduction – and all of this by photons? If the energy reduction was 50% each collision that would take a whole shebang of collisions FOR EACH ATOM – and it has to happen in those few hours that the HZE ions are crossing the solar system.
BTW, I miscalculated way back, when I said the 10,000 km/sec particles would cross the solar system in about 3 hours and 45 minutes. I'd asked everyone to check my numbers, and hadn't heard back that it was wrong. But now I recalculate and see that it is about ten days. Light will cross in 13.4 hours or so. So the HZE particles would cross in something longer than 13.4 hours – say 15 hours. Compared to the 82 years it takes Neptune to go in its orbit to the other side of its orbit, both are huge decelerations, over 99%. And as Trent pointed out, the momentum is squared, so you've got 99.9 to three decimal places energy reduction – and that energy had to go somewhere. Where?
Zoran –
…..”However, even the solid iron would fell apart if big enough.”
What does “fell apart” mean? Collapse in on itself?
…..”The very reason for this is that the object would be burdened by a fairly static TENSION of weight, not with acceleration pressure, as you hastily assumed. There is a great difference.”
I never talked about “acceleration pressure.” Gravity as measured on the surface of any large body (or in the air or underground, too) is subject to the acceleration of gravity. Between the surface of Earth (1 G = 9.81 m/sec^2) and Jupiter (2.52 Gs = 24.79 m/sec^2) things will only weigh 2.52 times as much. Period. That is WAAAAY to small to shred solid objects.
Take a block of wood that weighs 100 kgs. Put on top of it a weight of 152 kgs. The total weight on the bottom surface of the block of wood is 252 kgs. Now, stand around a wait for the wood to shred. I will see you in a few millennia. Or when the wood decays away.
Do the same thing with a piece of stone of 100 kgs, that won’t rot away. It is going to be there for geologic eons.
No shredding, simply because something got close to Jupiter.
I’ve worked with many solid materials, some weak, some strong. Even the weak ones would not shred in Jupiter’s gravity. Except maybe balsa wood, styrene, and styrofoam. And maybe cork. Elastomers would all creep (technical term), yes (at different rates. Other factors (temps, pressures, cosmic rays, etc.) would affect the results. But you wouldn’t SEE things shredding, except really WEAK and pliable materials. In general, the internal shearing you envision simply isn’t true. They all have levels that have to be exceeded, and a 2.52 factor isn’t enough.
Zoran –
“If you have a solid rotating ball of iron, it would tear at a depth where the tensile strength of iron is exceeded by the weight of the material above (vector of force pointing out of the ball’s center, not in).”
You need to take a course in mechanical engineering, Zoran. You have a distorted picture of what unit stresses (technical term) are all about.
I think the 9/11 conspiracy guys would love you.
Zoran –
“This issue is what those dreaming about a space elevator have to deal with. Breaking height for Al is 10.6 km, for Ti 5 km, and for iron even less than that.”
WHOAH, DUDE!
You are saying that AL is stronger than FE and TI????????????
Pardon me, but you are simply wrong on this.
I have my own reasons for telling those space elevator people they don’t know what the hell they are talking about, but you are on the right track. You just either misstated your numbers or got some bad info.
Even if everything else went right, when they went to attach the elevator to the satellite, the mass of the satellite changes to include the weight HANGING from the satellite. AND: The center 50% of the elevator is going at the same angular velocity as the satellite, but not enough to be in stationary orbit at that height itself.
In addition, EVERY mass that they tried to move up the elevator would unbalance the entire mechanism – in both gravity and angular momentum.
In addition, how could they string the elevator up that high? They’d need a construction superstructure to stabilize it ALL THE WAY UP. If the elevator is cables upon which a creeper elevator rolls up, then while being built the thing has NO capacity to support itself or brace itself. The radius of gyration (technical term) of the thing would get completely out of whack in the first mile or less. And remember, that when you thrust DOWN to lift a mass UP, the down force has to be greater than the mass – otherwise the mass doesn’t rise. And that mass is going to pull DOWN on the satellite. And the satellite – which is finely balanced in place – has no PURCHASE on anything – no way to “dig in” to resist (technical term) the downward pull. Every mass lifted up would be an arithmetic additive lowering of the satellite.
And when it lowers its altitude – even a little bit – it will increase its ground speed! NOT GOOD!!!!!
Add in all of the atmospheric forces – winds primarily.
The FLOPPINESS of a thing that long and un-braced (technical term) – which is what the radius of gyration is all about would make Galloping Gertie look like the Rock of Gibraltar. https://www.youtube.com/watch?v=CsKKDLKYsVU
. . . Stopping HZE particles with photons would be like trying to stop a runaway freight train with a feather. Too much kinetic energy and far, far, FAR too feeble of a tool to do the job. Way out of proportion with what photons can do. Remember this: Photons hit US all the time, and we don’t even FEEL them. Feather. Freight train. Feather. Freight train. Doesn’t work.
Steve,
HZE ions are fully ionized. They cannot emit any photons because they have no electrons. No electrons – no photons. They are not slowed by radiation.
“that energy had to go somewhere. Where?”
HZE particles can only be stopped by a collision with another particle, most likely a lone proton of a hydrogen atom somewhere in space. When they do, all the kinetic energy of their almost speed of light motion turns into a shower of exotic particles, first pions, which immediately decay into muons (after travelling merely few meters). Muons last enough to go for several km, before they decay too. At the end, you end up with protons, electrons, neutrinos and gamma ray photons. You are left with less than 1 electron’s mass worth of kinetic energy at the end. Kinetic energy turns into particles, plain and simple.
I don’t know why do you keep saying that a collision has to happen within the solar system. They could do it anywhere in the Galaxy, at at any time. The point is that over 8 billion years since the Big Bang, enough of them has done that in the small area from which the solar system begun, that 0.17% of the Sun is made of atoms heavier than boron. That small area used to be several light years before the gas collapsed to form the Sun et al..
Regarding eta Carinae: “You’ve got to be kidding. The two events are going to coincide?”
Yes. Eta Carinae recently erupted. It is going to erupt over and over again, until it sheds off 60 to 80 solar masses in total out of the initial 100 (or 120, whatever it was). Then it would explode, ejecting the last 10 ro 20 solar masses. This would happen within the next 100 ka or so. It could happen tomorow, too. nobody can tell with certainty. The star is completely enshrouded in its own debris and is not clearly visible. These clouds of debris would not go very far in 100 ka, as they are not moving very fast. Maybe only few light years. The SN blast would catch them quickly. This is the normal behaviour for these heavy stars. Estimated total lifetime for eta Carinae is only 4 million years. How many such stars there have been during the life of the Galaxy ? Hundreds of millions.
Steve,
“Take a block of wood that weighs 100 kgs. Put on top of it a weight of 152 kgs. The total weight on the bottom surface of the block of wood is 252 kgs.” “You need to take a course in mechanical engineering, Zoran. You have a distorted picture of what unit stresses (technical term) are all about.”
No. This is pressure, not tension. You apparently don’t even know what a ‘tension’, nor tensile strength is. Maybe you need to take a course in mechanical engineering. Tension is what a rope experiences when something is attached to hang upon it. If you have 3 ropes (tethers), of Al, of Ti and of Fe, how long do you think a rope can be before it snaps due to its own weight. Fe is about twice stronger, if I recall it correctly,but 4 times denser than Al. Therefore, breaking height (length of a tether that bears only its own weight while it hangs) would be shorter for Fe than for Al. Google down ‘breaking height’ for these materials, if you don’t believe me. Or google ‘high performance tethers’, like ‘Spectra 2000’ or ‘kevlar’. Or you can google out ‘tidal disruption’.
The only way that you can prove or disprove whether the Jupiter can shred an iron planetoid is that you calculate a distribution of forces for all points in the volume. If significant tension or shear appears anywhere within the volume of a ball (instead of pressure), it is game over. There are only 3 forces in the system to take care off: two gravitational attractions, variable by distance, and the centrifugal force, variable by radius. Their combination stresses the material. Calculate these stress diagrams for a planetoid of pure iron and prove me wrong, if you can.
Zoran says: “stress diagrams for a planetoid of pure iron and prove me wrong, if you can.”
I believe Zoran has suggested tidal forces as a mechanism to break a large body into small pieces, thus providing a means to expose material 100s km deep within the body. Zoran has certainly not proved plausibility for his hypothetical scenario, and doesn’t appear to feel any need to do so.
Zoran –
I keep talking about the solar system because THIS is where the heavy elements ended up – at least the ones that comprise that portion of the solar system bodies. WHY would I talk about particles elsewhere? That would make no sense.
And you talk about “At the end, you end up with protons, electrons, neutrinos and gamma ray photons.” That is in NO WAY talking about heavy elements. You are talking about free protons, individual protons. If that is what happened to the heavy elements, then the heavy elements got dismembered and are no longer heavy elements. So you haven’t solved ANYTHING, only UNDONE the creation of the heavy elements back in the supernova. How is that supposed to explain heavy elements WITHIN THE SOLAR SYSTEM? You go around in circles – and end up with FREE PROTONS????
That is no solution. Either you are explaining it wrong, or you don’t understand the question (which more and more seems to be the case), or you are running around, grabbing at straws.
The question is this: HZE particles, traveling at some ungodly percentage of C, the speed of light, somehow slowed down and ended up inside the claimed planetary nebula – within this particular solar system – having slowed down by some more equally godly removal of excess kinetic energy, by SOME mechanism, and the question is, “What was that mechanism that removed that kinetic energy?”
Impingements with occasional hydrogen atoms is a mechanism far to occasional and far too weak to have accomplished this. You invoke billions of years, as if that is IN ITSELF an explanation – the magic wand of nearly unlimited time.
But time is not a mechanism. Give me a mechanism.
Literally, invoking is no less miraculous than “The Moving Finger writes, and – having writ – moves on,” of Christian dogma. I.e,. the Hand of God. Or, “Since God can do ANYTHING, when God does something, who are we little humans to fathom the mind of God?” I reject THEIR miracle, and I reject science’s miracle.
Substituting TIME for GOD – NOT science. Why can’t you just come out ans say, “I/we don’t know?” instead of all this speculating about mechanisms, and then invoking lots of time, when nothing else works?
David –
What Zoran isn’t telling you is that tidal forces don’t apply to SOLIDS. Tidal forces only apply to LOW SHEAR fluids.
Solids have stronger bonds, and especially crsytalline materials – like metals and rocks – have very strong bonds. Those very strong bonds are like you waving a feather – or another bar – near a steel bar and thinking that that is going to make the steel flow like a fluid. That simply doesn’t happen.
Anyone who knows about metallurgy or crystals or materials science knows this. I don’t pretend to be an expert at either, but I know enough to know that Zoran is speculating about things he doesn’t know about.
Zoran believes that forces only 1/4 of a magnitude greater than the surface gravity on Earth will cause EVERYTHING solid on Earth to flow like melted butter when it comes close to Jupiter. That idea is SO WRONG. On a smart scale of 1 to 10, that is a 1. All you have to do is look at numbers.
PROPORTION………
Proportion is something some scientists don’t appreciate. A rock sitting next to a rock does not merge with the other rock. That regolith sitting on 67P may have sat there for millions of years, and it is never going to flow into and become part of the solid body, unless something else happens, like a helluva lot of heating, at the minimum). A bullet going 2200 meters/sec cannot merge with the target materials it hits. Instead it tears them apart, making a hole or blasting the material to smithereens. 2200 meters/sec (2.2 km/s) in terms of motion within the solar system is VERY SLOW. Bodies right now, only going at 20-30 km/s, when they HIT, they destroy. They don’t merge.
Zoran pretends that he knows what the relative velocities were back 10 to 4.6 billions of years ago. He tells you what the orthodox thinking is. But he doesn’t know. No one else, does, either. If the relative velocities then were what they are now, then they have a problem, because impacting particles and bodies would have smashed each other to smithereens – then, as they do now. But Zoran is explaining that somehow the same laws of physics that we see now didn’t apply then, or that he can make up conditions – out of his imagination – in which such events could happen and not violate the laws of physics. He pops in some ad hoc explanations and expects us to accept them as real.
HZE particles that end up as free protons are supposed to become heavy elements? NOPE. The ONLY hypotheses that exist about the creation of heavy elements are that they were created deep within supernovae. He can’t just make up his own. I accept that that is where heavy elements came from – from inside supernovae. What I have a problem with is that somehow those slowed down here – specifically HERE – down from near light-speed (or 10,000 km/sec, take your pick).
Zoran questions why I ask about slowing down within the solar system, and my answer is because the planets Mercury through Neptune are here. What happened elsewhere in the galaxy or in other galaxies are only peripherally part of the discussion.
Zoran –
Your schtick on eta Carinae sounds good, but if I go looking at papers on that star, I will bet dollars to donuts that all of what you’ve stated as fact is not fact at all but interpretations. Ones filled with caveats (“might have”, maybe”, could have”, “we think that”, “we suggest that”, “perhaps”, etc…)
You say yourself that, “The star is completely enshrouded in its own debris and is not clearly visible.” How many extra layers of guesswork does that “not clearly visible” create?
Seriously. You are talking to an engineer and talking about not even being able to SEE the thing you’ve ascribed all this history to. And then telling us it only lives for 4 million years – about the time since the first proto-humans. When you present something that is only hypothesis or the best understanding so far, will please you stop presenting it as FACT? Interpretation is not fact. If it was, then epicycles would still be taught in astronomy classes. PLEASE, tell us point by point, which assertions you’ve made are known to be solid and irrefutable fact?
Trust me, there are empirical astrophysicists who don’t accept a good deal of what you’ve asserted.
Zoran – “You apparently don’t even know what a ‘tension’, nor tensile strength is. ”
If you look at the passage you referred to, I did not talk about “tension”. I talked about “unit stress” – which apparently you did not look up and don’t know about.
As an aside, though:
All bonds within solids (and, I believe in fluids, too), are essentially tensile – regardless of the geometry of the forces applied. Shear and compression are simply special cases. In shear stress, the forces applied are lateral – normally considered to be applied at right angles. In compressive stress the forces applied are in line with but toward each other. And in all of them the bonds to overcome are tensile – cohesively between atoms and molecules. THAT is the unit stress – more exactly the “maximum unit stress” of a material, when one is talking about failure of the material. And this is what in engineering is normally what is to be avoided.
As to tensile strength, I have actually, on several occasions, been required to use Instron brand tensile and compression testing equipment in R&D, for experiments I was running for my PhD bosses, so, yes sir, I do know something about tensile and compression and shear, etc. In addition, I’ve designed scores of structures based on all of theses strengths/stresses – and none of them has fallen down yet. Including BRIDGES. You haven’t seen any of my designs on YouTube, failing, have you? I would be MORE than embarrassed if you did! While I have also designed parts of buildings, I can’t claim authority there, because in my states only architects and Structural Engineers (technical term) are allowed to claim such things.
…
Your “breaking height” google assignment ended in failure, because your term brings up only breaking height of waves on a shore.
However, a bit more searching and I was able to find “breaking LENGTH”, which seems to be what you were going for.
And that you won’t like. We will gow tih Wik for the moment, under “Secific strength”:
“Another way to describe specific strength is breaking length, also known as self support length: the maximum length of a vertical column of the material (assuming a fixed cross-section) that could suspend its own weight when supported only at the top.”
The table shows three metals, but is unclear about two of them.
“Aluminium Alloy” is given as 21.8 km. [FYI: Density = 2.80]
Titanium is given as 29.4 km. [Density = 4.51]
Steel is not listed.
Stainless steel is given as 25.9. [Density = 7.86]
Complicating this are two things. First, “normally (alloyed) steel isn’t given, and stainless steel is nominally stronger. Secondly, is that term “alloy”. The term alloy can mean any one of SEVERAL – or DOZENS – of various metals, all of which would come under the main heading, but which can vary a LOT in terms of strengths. Alloying materials are almost ALWAYS included to improve the yield strength (tested in terms of tensile strength), and almost always mean a stronger metal is included. Aluminum alloys are especially true in this regard. NOBODY uses aluminum BY ITSELF, unalloyed.
Aluminum alloys – three main ones in the USA are 2024, 60601, and 7075. Each has sub-alloys. The strongest of these is 7075 (used in aircraft) – and that is probably the only one worth considering… The other two are rather generic and weaker. But 7075 also has up to 0.5% IRON in it. As well as up to 2.9% magnesium, 2.4% nickel, and 0.28% chromium. These are all metals stronger than AL. So, in saying “aluminum is better”, you’ve fallen into a trap of your own making, in that there IS no such thing as straight aluminum sold out there for building anything out of. Whatever aluminum is strong is strong for reasons other than the aluminum within it.
And even with this, the “aluminium alloy” shows less breaking length than the stainless steel and less than the titanium, too.
So, you are busted on that one.
The bottom line, though, is not whether any of those can hold up their own weight for 20 or 30 km of length. Not when the stationary orbit is 36,000 miles. None of them can be considered an option, and neither can any carbon nano-tubes or “colossal carbon tubes”. Carbon nano-tubes only have a breaking length of 4716 km, and colossal carbon tubes go up to 6066 km. (And none of that even includes the weight of the cargo or cargo containers or elevator box/drive mechanism…)
On that alone, the idea of an elevator to a satellite is busted. Even if one is to think in terms of suspending half the weight from the satellite, none of those gets even halfway. But the weight hanging down would also pull down the satellite – partly because at ALL heights less than the satellite stationary orbit the mass is no longer in stationary orbit. AKKKK! Does it pull the satellite backward? Or forward? Hahaha I haven’t even looked at that, and don’t need to – The thing fails long before even addressing that.
The single STUPIDEST part of the elevator is that in order to string it, there needs to be some anchoring, some support for it – and WTF kind of support can one have at any but the bottom 1 km or so? Ever heard of construction site collapses? When the rigging fails to support the unfinished weight of the structure, people DIE. So such concerns are IMPORTANT.
Steve:
You appear to have made an interesting point, that the pallisite meteorites can’t be explained under the conventional solar system formation theory.
But, you go off on all these pointless and incredibly verbose tangents rather than staying on the central question.
Rather than going on about space elevators and other distractions, why not research the issue in the scientific journals and summarize what you find?
David –
I didn’t bring in the space elevator. Sorry. Won’t discuss it again. I agree with you on that.
As to pallasites, I happen to have just been reading n them in the only part of a paper I could access, and in none of it is there conclusive evidence AT ALL that the pallasites or HED meteorites came from Vesta, whose actual name now seems to be 4 Vesta. Though these are asserted to have come from 4 Vesta, the one paper from March this year says,
That’s where my access ends, but it is enough, I think.
What does it say? Without going off on pointless and verbose tangents, let’s see…
They are confused, because they expected to see olivine in that crater that is 100 km deep. Why do they expect to see it there? Because differentiation means a core, a mantle and a crust. And because they assume 4 Vesta is differentiated, and they can see 100 km deep into it but still can only see crust materials. 4 Vesta is 525 km across, or 275 km radius. It’s amazing and fortunate that there IS this one place on any large asteroid with such a deep look inside. So, they can see 36% of the way to the center of the asteroid, but still no mantle material – olivine. That is a big problem for their view of things.
So far, it doesn’t even occur to them that perhaps 4 Vesta is not even differentiated at all. I don’t know whether it is or not, but at this point the ACTUAL evidence seems to say NO.
What does that lack of olivine in that crater mean, in this Vesta-pallasite-HED discussion?
If the olivine is not found deep inside Vesta, then the claim that pallasite and HED meteorites came from 4 Vesta is wrong. In that case, HEDs and pallasite must have come from somewhere else. That is why the researchers are “confounded”.
But in the bigger picture, it argues even against the assumption of the differentiation of asteroids altogether. If 4 Vesta is not shown to be differentiated, and if it is one of the very largest asteroids, then it would suggest that perhaps NONE of the asteroids are differentiated.
But isn’t there olivine on the surface of 4 Vesta? Shouldn’t that tell us that there is a mantle on 4 Vesta?
It might, but it also could just be a thin coating spread over the surface from impacts of meteors. It is not clear one way or the other. They look at the surfaces of bodies through telescopes and spectroscopes and see what is on the surface. But just like on Earth, what is on the surface is not necessarily what is underneath. On asteroids they have to INFER what is underneath – until they can go and excavate.
But they can’t excavate 100 km on 4 Vesta. Heck, they can’t even do that on Earth.
The one paper I’ve alluded to several times talks about how big a planetoid needs to be to be differentiated – based primarily on the forces required to form olivine. This paper was about actual lab tests. What was the conclusion? A body has to be 3,000 km in radius to make olivine. 6,000 km big. MARS is only 3389 km across. The Moon is only 1737 km. 4 Vesta is only 550.
So this all means what? That if their lab numbers are right, then even Mars and the Moon may not be differentiated. That is a BIG deal, to their ideas about the formation of planets.
But bigger than that is that olivine that is certainly found in meteorites could not possibly have come from asteroids or small planets – meaning that the meteorites themselves also did not and must have come from a larger body.
And the corollary to that is that if the olivine in meteorites comes from a larger body, then the meteorites – and perhaps the asteroids and comets – themselves are NOT remnants of the early solar system at ALL.
The evidence seems to point that way. And further, their confoundedness is rooted in their not having understood this correctly. And each bit of evidence seems to show their misinterpretation more and more, but they can’t grasp how wrong they are, so instead of abandoning their ideas, they have had to manufacture explanations, such as that “orthopyroxine” is masking the olivine.
Bottom line:
1. The evidence so far does not support that HEDs or pallasites actually came from 4 Vesta and weakens that interpretation.
2. If no evidence to support it is found, then the hypothesis that differentiated asteroids exist cannot be supported.
3. And if no actual evidence shows clearly that such differentiation occurred, then a major part of the current planetary formation theory is based on only words and ideas, not evidence. They are LOOKING for this evidence, right where it SHOULD BE, and it isn’t there. So far. This is a problem for them.
This is NOT the only paper I’ve seen that shows how weak this olivine-Vesta-HED-pallasite connection is.
Misc –
The number in front of asteroids is the sequence of discovery. Ceres is more properly written as 1 Ceres as it was the first one to be discovered. Vesta was fourth. I think the list is up to around 140,000 including the newly discovered moons of the Pluto – Charon system.
Rosetta has observed sinkholes on 67P. Mechanism appears to be sublimation of ice spewing dust from layers. The layers collapse in what look like circular sinkholes. Fun stuff.
http://phys.org/news/2015-07-rosetta-spacecraft-sinkholes-comet.html
Final bit of news is a planet being caught in the midst of forming a mere 335 LY away. We keep seeing more and more of the process.
http://phys.org/news/2015-07-birth-planet.html
Final observation is if olivine and pallasites have been found on meteors / material though to be from Vesta and if they have been observed on and in crater walls, then by definition they can be formed inside a body less than a 3,000 km radius. So there must be another mechanism. Cheers –
http://www.hou.usra.edu/meetings/lpsc2015/pdf/1107.pdf
agimarc –
Thanks for the stuff on 67P. Sinkholes means one more thing for them to crowbar into their ideas.
Not quite, on the Vesta olivine “on and in crater walls” point. It seems that the one place they NEEDED to see olivine in a crater is the one place they did NOT see it – in the big crater at the south pole, Rheasilvia. They’ve only seen olivine on the surface of Vesta, and predominantly in the northern regions. One paper is even entitled “Exploring Exogenic Sources for the Olivine on Asteroid (4) Vesta” – http://arxiv.org/ftp/arxiv/papers/1502/1502.03189.pdf
AHA! It seems that is the same paper as the one you gave a different link to. Good find, both of us!
It seems that in general olivine is quite rare in meteorites, and in asteroids, too. One source said only about 7 out of 1000 meteors shows any olivine. It all has developed into what they refer to as “the missing olivine problem“. The problem is at least in part due to the iron-nickel meteorites and asteroids. Those are all thought to be the remains of the cores of differentiated asteroids (ones with crust-mantle-core layers), after the crusts and mantles had been scoured away by erosive impacts. Where olivine comes into the problem is that they believe that mantles should be around 75% of the mass of differentiated asteroids, so if the crusts and mantles were stripped to leave the iron-nickel cores, they would have had to remove the mantle material – which is predominantly olivine. But only those rare meteorites have olivine.
In fact, it seems (correct me if I am wrong) that the main reason they focused the attention on Vesta in the first place is that it was the only place they were seeing olivine. And they made all of these constructs about how olviine everywhere came from Vesta – because they’d seen olivine on the surface of Vesta. And in the process, they jumped to the premature assumption that the olivine was down in the mantle of Vesat. This is one thing specific>/b> that the Dawn mission was looking for inside Rheasilvia – to confirme all of those conclusions.
But then Dawn didn’t FIND the olivine.
Egg on their faces? Not yet, and they are trying to figure out what is going on.
So, the planetoid/asteroid guys are hung up on just about the same thing that I am, though this hang-up is not readily apparent to the general public. If the olivine is truly not inside Vesta – and I am betting that it isn’t (as you all know) – then they have a BIG problem. In fact several.
For one thing, they will have to UNCLAIM the name “Vestoids” for the meteorites that have olivine, because the reason for that assignation was because everyone said Vesta has the only olivine around.
As to the missing olivine relative to those iron cores, this one http://arxiv.org/ftp/arxiv/papers/1502/1502.03189.pdf “IRON AND STONY-IRON METEORITES AND THE MISSING MANTLE METEORITES AND ASTEROIDS” has this:
So, much of this is very uncertain. But they ARE fully recognizing that olivine HAD to come from the interiors of differentiated bodies. And they are trying to figure out HOW it got out from the interior mantle layers. That was exactly my original point when I found out about the olivine in the Allende meteorite. They talk in terms of long pulverization processes, and that may be true. But in doing so, they run headlong into a wall – a wall of “WHERE IS ALL THE OLIVINE? It should be out there somewhere?”
So, agimarc, not to be difficult, but I won’t agree that this is correct: “by definition they can be formed inside a body less than a 3,000 km radius“. I DO stand by that paper, “Pressure-Temperature phase diagram for the Allende meteorite” at http://onlinelibrary.wiley.com/doi/10.1029/95JB00049/abstract.
There is ONE possible solution that CAN be larger than 3,000 km radius and which is NOT an asteroid or space dust. “Another mechanism“? Yes. An exploded planet, as per all of the reasons given, page after page, by the late Tom van Flandern.
I don’t expect anyone to sign onto that idea, but it seems more plausible to me now, than before.
Sorry David, if this was too long-winded…
Damn typo on the formatting there……
IMHO, it is an absolute certainty that pallasites came from the core-mantle boundaries of some differentiated bodies. That iron melted around the olivine silicate crystals…
Therefore, somewhere BEFORE (at least SOME of) the asteroids/meteoroids existed, a large body differentiated into crust-mantle-core. And the pulverization did not reduce all the materials above the cores to dust. (Otherwise no one would have any clues…)
Hi
………..pebbles and dust can still be falling on our heads………..
http://news.sciencemag.org/2015/07/astronomers-spot-pebbles-turn-planets?utm_source=facebook&utm_medium=social&utm_campaign=facebook
Steve – Good discussion on Vesta. At some level we are doing our version of the blind men and elephant – seeing the same thing and coming up with different descriptions / explanations.
OTOH, I will consider exploding planet if you will consider pallasites / olivine in forming in smaller, differentiated bodies.
Interesting they didn’t find any looking at Rheasilvia but do find some in crater walls.
Several explanations present themselves (and we are into the realm of arm waving) –
– It was introduced from off world
– It was created by the impact event itself
– Some other mechanism creates it during accretion, and that mechanism operates better the larger body you have. Small body like Vesta, not much. Larger bodies, more.
As usual, the more you find out the more you find out you don’t know. Fun stuff. Cheers –
agimarc –
FYI, I am not WEDDED to the exploding planet hypothesis. But for the likes of me, I can’t figure out why it is not even among the possibles being considered – EVER. It seems to me that there should be two camps, fighting like dogs and cats. But everyone was swept to one side of the aisle 200 years ago and if someone mentions the XP, everyone else slides to the far end of the bench. My copy of can Flandern’s book is 2000 travel miles away from me; otherwise I would list a few of his arguments. I am certainly OPEN to his cause, and I consider it along with the orthodox, and when I disagree with either I have the annoying habit of voicing it…LOL
I will consider pallasites or olivine requiring more pressure than can exist in self-gravitated small bodies. In all likelihood theses formed in some process that isn’t being considered now, by you or me or anybody out there. Whatever it is, I am blind to it.
Yesterday I read this, in the 2006 book “Meteorites and the Early Solar System II”, by Loretta & McSween:
“Most meteorites are fairly strong rocks (no doubt with selection effect due to survival of atmospheric entry). Measured porosities of chondrites are typically less than 10%, with little correlation of porosity with metamorphic grade. This result suggests that lithification was not simply due to heating within parent bodies, but involved pressure as well. [My exact starting argument in all of this…] However, lithostatic pressures within asteroid-sized parent bodies are not sufficient for compression and lithification. [ditto] The mean internal pressure in a body of density (d) and radius r due to self-gravity (half the maximum value) is pi x G x d^2 x r^2 / 3, or ~1 MPa (10 bars) within a body with radius 100 km. This is comparable to pressures a few tens of meters below Earth’s surface; much higher pressures are involved in lithification of sediments.”
When they say “much higher pressures” they aren’t kidding. On Earth such pressures only exist down below ~80 km deep – not “a few tens of meters” or so. And that is with EARTH’s mass. Vesta’s mass is 2.6e20 kg, about 1/23,000ths of Earth‘s 6.046e24 kg. Other people might think that is sufficient mass and self-gravitation; I don’t. I simply can’t. And if they do, I’d like to hear their arguments and see their numbers.
But, let’s say for argument’s sake that Vesta is on the edge of such pressure (which I don’t think is true at ALL). And let’s say that that makes Vesta “hard as a rock”. Meaning it successfully would have been able to lithify. But then how do we explain the smaller rocks called asteroids? If even a 100 km radius body doesn’t have the pressures to lithify, how do we explain millions of little solid rocks whizzing all around the solar system?
…
The olivine they found on crater walls was light-colored surface materials in various locations around the asteroid – plus in craters (Arruntia and Bellicia) on the northern half of Vesta. They realize that they have a problem: The olivine is lying on the surface, but certainly did not appear to come from the deepest crater.
The one paper I linked to is already suggesting that the olivine is exogenic (off-world).
Out of the three possibilities that you listed, the last two are worth general consideration, of course, but do not seem to be true so far. The impact of Rheasilvia simply does not show olivine – and everyone was LOOKING for it, specifically. If it was there, it would have been found. Kind of like the WMDs in Iraq back in 2003.
The “some other mechanism” possibility exists, but whatever it is is still a mystery and can only be put down as a dark horse, at present.
…
The “missing olivine problem” is a doozy for the astronomers, because, according to extrapolating earth processes out to the solar system (which they should do, IMO), mantle material – mainly olivine – should be about 3/4 of the meteoritic and asteroidal material out there. Yet it is not common at ALL, so far. But even the KNOWN olivine still has no explanation, either.
My assessment of the situation about olivine and the orthodox accretion theory has to be that they are groping in the dark and fumbling with speculations – that come from scientists and so are given respect, but still are only speculations.
Where I came from, trying to draw conclusions before the facts are in was seen as not good science. In fact, it was SERIOUSLY discouraged. All that can do is to make people look dumb. And it gets the science itself exactly NOWHERE.
Gentlemen; Pierson’s link to the article on DG Tauri says that gravity will eventually cause the dust and pebbles to coalesce into a proto planet. Again the question remains: What gravity? WHERE DOES IT COME FROM? None of the pebbles have any appreciable gravity of their own to bind and hold other pebbles together. Once there is a body large enough to attract and hold other smaller pieces together I can see that happening but—What starts the process????
Jim,
Gravity is irrespective of the quantity of mass. Any mass, no matter how small, has a gravitational field, and all gravitational fields interact with each other.
The smallest grain attract each other into larger and larger grains, and the larger grains coalesce into even larger grains. Until the collective gravitational field is strong enough to apply enough pressure for the later heating and compression.
Now remember that the proto planetary disc is still very hot from the ignition of the parent star. In a recent published paper, it was found that in a undifferentiated disc, the temperature at 50AU out from the young star is greater than 600 deg. C, so fifty times farther away than we are from our sun the disc is more than 600deg. C. of just the dust cloud.
And in another recent study of a super nova nebulae, the temps of the gas and dust cloud is more than a million deg C. at several light years out from the super nova itself.
Jim and CevinQ –
CevinQ – first of all, your opening line is so utterly wrong I don’t know where to begin. OF COURSE gravity is not “irrespective of the quantity of mass”. Holy crap, you never heard of Newton? F = G x m1 x m2 / r^2? m1 and m2 don’t COUNT????? Oy vey…
BUT, gravitational attraction has only SO much to do with masses and more to do with distance. In fact, the attraction is the inverse square of the distance, so distance is a much more important factor than the masses. Yes, “all gravitational fields interact with each other”. But discussing them without considering distances and motion relative to each other is leaving out two factors far greater in magnitude than their individual “gravity wells”. It’s like talking about ice cream and not mentioning that it is cold.
If you take two particle bodies of the same diameter and touch them against each other, then D = 1 diameter. Separate them by only ONE diameter between them and the gravitational attraction is reduced 4-fold, down 75% – D = 0.25. Double that c/c distance and the attraction is now 16-fold less, or D = 0.0625 versus when they were touching. Now put them out in space, where distances aren’t measured in body diameters but in even only tens of meters apart, and the attraction is so close to zero that the the two bodies’ attraction is essentially zero.
This rapid diminishing with distance is NOT unimportant. Instead it is EVERYTHING. In a pile of particles, only the closest layers around a particle has any real effect on it. Particles only 4 or 5 layers away have next to NO effect.
Do the numbers; I have.
NOW put them in relative motion. One whizzes by the other at some distance away. The gravitational attraction goes from near zero to some value a bit higher, and then as the distance increases again, the force drops to near zero again – and THEN keeps on shrinking as it gets farther and farther away – by the inverse square law. At what point in that whizzing was one particle supposed to grab onto the other one?
It is completely proper to have them in relative motion, because in a nebula the particles are not in the same plane, but instead start out in a cloud, and it takes TIME for the cloud to draw down to the same plane, into a flattened disk. In doing so, the particles would overshoot the disk plane and then zig-zag up and down above and below the disk plane. They all do NOT achieve the same velocities as all of this happens. So far EVERY model of attraction in the disk plane that I’ve seen (I went looking) talks about laminar flow, but this is invalid, because laminar flow would not happen.
What is laminar flow? Smooth flow. Non-turbulent flow. Turbulence comes from particles traveling at different velocities and in different directions. In laminar flow, particles move smoothly together, in the same direction and at the same velocities. Such as state would not have occurred. Even NOW there is no laminar flow in the solar system, and there certainly wasn’t in the beginning of the planetary disk. If there wasn’t any laminar flow at the beginning and not now, there is NO reason to think that there ever was, at any time in between.
One book discusses this thus:
[from “Meteorites and the Early Solar System II”, Laretto and McSween (2006), pg 475]
Note that all of this is discussed in terms of PRE-SOLAR – before the Sun was “ignited”. Therefore we cannot be talking about 600°C at 50 AU, because the Sun hasn’t lit up yet.
So, what these authors are discussing is that particles moving around together in lock-step could not have been possible. The particles were all moving relative to each other – whizzing past each other. That means collisions, not gently sidling up to each other and shaking hands in a sedate gravitational “howdy-do”.
Jim – the gravity comes from the masses of each particle, attracting every other particle.
Steve,
I wasn’t talking about the force a gravitational field puts on another object, I was talking about the fact that gravity is a property spacetime. All masses generate a gravitational field regardless of their size. The smallest grain of interstellar dust will attract gravitate towards the nearest mass.
Yes the force of gravity drops off with the square of the distance. But even though the forces in the macroscopic world are very small, they are still there , gravity goes down to the quantum level.
Using your logic a star could never ingnite, because those random H atoms would never coalesce
Test post – I think something is wrong with the ability to respond to comments. Cheers –
Apparently not……
Steve –
The problem I have with XP’s are threefold:
1. We have never observed one or its aftermath (that I know of). That list includes nearly 2,000 planetary systems.
2. I have a hard time figuring out where the explosive impulse comes from, other than an impact event with a large caliber body.
3. Where does all the out of plane material go? Better yet, why aren’t we seeing any of it?
Pressures and temperatures of olivine formation don’t bother me a lot as there are no time variables that I can find in the process. This means (at least to me) that olivines can be formed via atmospheric deceleration or via impact events.
But for olivines on Vesta, I would note that it moves us smartly into chicken and egg land. In other words, which comes first? And if the olivines were introduced from elsewhere, where did they first originate?
Finally, the early clumping of dust into balls was observed on ISS via weightless experiments. I believe the attractive mechanism is electrostatic. An no, I not an electric universe kind of guy. Cheers –
Here’s another try with the ISS clumping experiments. Cheers –
http://www.psrd.hawaii.edu/CosmoSparks/July14/electrostatic-particle-aggregation.html
agimarc –
(Crap! I lost this whole thing when it was 90% done and have to do it again…)
XPs – my responses:
1. “We have never observed one or its aftermath (that I know of). That list includes nearly 2,000 planetary systems.”
That depends. Seeing one happen in an exoplanet system? How long have we even known about exoplanets? Since 1992, 23 years. Not even an eyeblink. When we see a star being formed what we see is a VERY slow-motion event – so the event lasts long enough for us to observe a tiny, tiny bit of its birth. An exploding planet or destruction of a planet by impact is an instantaneous event – perhaps lasting only minutes or hours. The odds of us looking in one of those few exoplanet systems within the very small time frame of such an event is nearly zero. We could look right at one for centuries and never see anything happen. And if there are multiple planets in a system, and one of them explodes, are we looking at the right one at the right time – or one of the others? DO NOT FORGET that we are looking for planets mainly in the Goldilocks zone. If the asteroid progenitor existed, it is FAR outside the goldilocks zone.
Had you discussed exoplanets in, say, 1985 you would not have been laughed off the podium, but you wouldn’t have gotten too much cred, either. We looked for them for HOW long before finding them? So, saying that in the 23 years we’ve been looking at exoplanets we haven’t seen a planet explode, that is not enough time to see ANYTHING. 2,000? How long have most of them been known? And average of maybe 6 years? I assume the discovery curve is exponential, so 6 years seems like it may be close to the average. If 23 years is less than an eyeblink, then 6 years is kind of like time on the atomic scale.
2. “I have a hard time figuring out where the explosive impulse comes from, other than an impact event with a large caliber body.”
I don’t disagree with your point. I have not had a good answer in the past. But then, I’ve had to put it on a back burner for along while dealing with other things, intending to come back to it. An impact to me also seemed like the most obvious mechanism. After all, if small bodies have impacted since the beginning of the solar system (orthodox view), AND if large bodies accreted into the resonant zones dictated by Kepler’s Law, then is it so hard to believe that two large bodies might try to occupy the same space at the same time? And if at impact velocities similar to those we KNOW happen now, two big ass bodies would BOTH self-destruct from a good head-on collision.
But you got me thinking also about other possible mechanisms, and perhaps there IS one. The hat in the Earth’s core is supposed to be at least in part from the uranium that “sank” to the bottom and into the core. Uranium is rare on the surface because most of it went to the core and kept going. Now, what could cause Uranium to go “nukular”, as George W Bush would say? All you need is a critical mass. Hell, you don’t even need pressure. And critical mass is NOT contingent upon an overall percentage, either. It has only to do with the amount of MASS and purity – the concentration of uranium, as it were. We honestly don’t really KNOW the percentage of uranium in the core, but most of it is seen as being in the inner core. The percentage is calculated based on assumptions having to do with the overall Earth density. They especially are only recently beginning to come up with better evidence about the inner core, and I assure you from my reading that it is ALL based on assumptions about the interpretations of the data that they have. Most of the overall core is iron, but some portion of it is uranium. All of it is contained by the mantle. So, if a mass of uranium in the core goes critical, what happens? In a volume close by, the pressure spikes. The viscosity of the molten iron is high, so the conductance of the pressure spike should reach father than if it were under less initial pressure. The shock wave COULD conceivably cause OTHER uranium pockets to fission explosively, too. The contained explosions could conceivably create enough pressure to fusion the iron, or something else in the core. This containment of a fission explosion triggering fusion is exactly what is done in an H-Bomb, a fusion bomb.
Now, the H-Bomb is called that because it is hydrogen that fuses. Could hydrogen exist in the core? Or any other light element? I don’t THINK so. But I do know about something called “hydrogen in metals“. You don’t know about it? Of course you don’t. Almost no one who is not a metallurgist does. But among them hydrogen in metals is a BIG DEAL. Hydrogen in metals causes crystalline fractures and metal failure in cases where the metal should not fail. It is such a big problem for metallurgists that there are THOUSANDS of papers on the subject. Now, this problem is currently only studied in “cold” crystalline metals, and is thought to occur because the hydrogen migrates in GREAT quantities into the spaces/planes in the lattices of the crystalline structure. Hydrogen has a great affinity for such places – between the metal molecules. And the affinity is so great that the hydrogen just keep on accumulating within the lattices, building up pressures that are nearly high enough – BY ITSELF – to fuse hydrogen. I had reason to look into this myself, in 1989, at the time of the Pons and Fleischman “cold fusion” uproar. And it was metallurgists who pointed me to it, telling my boss that the physicists don’t know about this stuff, and that the physicists were exactly the wrong people to look into Pons’ and Fleischman’s work BECAUSE they know nothing about hydrogen in metals. I found a bland statement in a paper back then describing how high the pressures could get. Converting from Gpa to PSI, which my brain needed to do back then, it came out that the pressures discussed reached 10 million PSI – right at the level that is needed for fusion. And the paper author didn’t even seem to realize that that pressure IN THE LATTICE was fusion-level pressure. But my metallurgist cohorts pretty much said as much, when they laughed at the physicists checking out Pons and Fleischman. They ALSO pointed out that only SOME palladium will give such high pressures, and they laughed, saying that the physicists who didn’t know this would probably use the wrong crystalline palladium and see nothing, but that SOME would use the right palladium and replicate Pons and Fleischman. And that is exactly what happened, at least on the surface. The nay-sayers yelled loudest and got all the press, but the ones who DID replicate this were drowned out in all the scathing remarks about how stupid Pons and Fleischman were.
But can hydrogen in MOLTEN iron act the same way? I don’t know. Probably mnot, but it may be worth looking into. Not by me – I don’t have any ultra-high pressure anvils laying around, nor any high-temp kilns. But, first of all, looking at SOME numbers, the pressures down there are in the 30 Gpa range and up, and increasing with depth. The lower mantle is at 26 Gpa and more. 30 Gpa is about 4.4 million PSI – almost half the pressure to fusion. And it being contained by the mantle above, any explosion/rapid expansion by a fission explosion would increase the pressure significantly. It is all closed in and has nowhere to go. IF – and I do stress the “IF” – there IS any hydrogen down there, with the iron, then that hydrogen would be at risk of fusing.
Enough to blow up a planet? Probably not, but maybe close enough in theory to do something more than my back-of-the-envelope look at it.
All of that is off the top of my head. It probably has SOME errors in numbers or reasoning. Maybe all of it. It’s the first time I’ve put thought into it.
3. “3. Where does all the out of plane material go? Better yet, why aren’t we seeing any of it?”
Hahaha.. This one I had fun with. To begin with, we ARE “seeing any of it”. Take a look at this graph of the inclinations of the asteroids – extending from within the orbit of Earth to the empty space just inside Jupiter – but also including the Jovian Trojans. http://www.nature.com/nature/journal/v505/n7485/fig_tab/nature12908_F1.html
See those inclinations? They go up and beyond 60° inclination. That is 2/3 of the way to the system poles.
The planets’ inclinations max out with Mercury’s 7°, and with Venus at 3.39°. Notice on the graph that perhaps 2/3 or 3/4 of the asteroids are OUTSIDE that 7° range. (The 7° is on both sides of the plane of the planets, so the total range would be 14°.) Probably 90% of the asteroids are outside Venus’ inclination. I frankly was amazed when I saw that graph. I had NO idea that the asteroids were not lying peacefully along the plane of the planets. Instead their mean inclination is probably in the range of about 9 or 10°. Clearly outside the inclinations of the planets. Clearly many thousands of them are outside the range of the planets.
One is led to ask HOW those asteroids could possibly be out there. First of all, the accretion theory says that the material should – of its own accord – all gravitate down to the plane of the planets. Secondly, if THOSE are out there in that rarefied zone, then impacts should have become very rare things, and even the idea that impacts cause accretion (which I highly dispute) – HOW do solid objects form out there? Nothing solid should be out there. Why did those not gravitate to the plane of the planets 4 billion years ago, along with everything else? (Papers I’ve read state that this flattening out happened within a few million years, if not a few thousand – a surprise to me, that was.) If anything those should all be strengthless bodies – according to the thinking within the orthodoxy. Are those objects out there friable snowballs? Hale-Bopp comet, which came “over the top”, has an inclination of 89.4° – about as high of an inclination as is possible. It had a density of about 1/7th that of water, a weak body at best. But it had a LOT of material. Its nucleus was estimated variously at 30 km up to 80 km. That is damned near a planetesimal. Honestly, that is a LOT of accretion for an object on an 89.4° inclination, where almost its entire orbit is where you say there isn’t any material.
One of the interesting things is how high so many of the Jovian Trojans are inclined – even though they are in the zone within which Jupiter has done such an effective sweeping-up job.
“Pressures and temperatures of olivine formation don’t bother me a lot as there are no time variables that I can find in the process. This means (at least to me) that olivines can be formed via atmospheric deceleration or via impact events.”
Nope, on this one I am sure you are not correct. There is a HUGE difference between a sustained/contained pressure and a momentary impact pressure spike. Yes, they are both big, which can mislead in the case of olivine. Impact pressures are shock pressures, and they deliver specific evidence, such as impact cones and shocked quartz. Olivine needs a specific range of steady pressure. If the pressure is too low, the Magnesium silicate form orthopyroxine. At about 14 Gpa (about 2 million PSI) olivine does a solid-solid phase change and becomes other forms of magnesium silicate altogether – perovskite and magnesiowüstite. So, olivine is in a pressure niche, and that pressure has to be steady.
As to atmospheric deceleration, no to that one, too. Don’t forget that the atmospheric deceleration/braking is due to the resistance of the viscous fluid that is the atmosphere. The results are melting and vaporization – ablation. The vaporized materials are cooled (as they slow enough) to become individual grains of DUST – NOT crystals. If I had to characterize them, I’d guess that they re like ash or very small bits of slag-type material. But that is just a guess.
Steve:
The authors of this paper:
http://www.higp.hawaii.edu/~escott/Yang%20ea%20pallasites%202010.pdf
feel that the pallasite meteorites originated from a single body. You feel that the size of the body must be large, to produce the crystalline minerals observed, what data are you going by to make your size and pressure calculation?
I don’t FEEL that the size of the body has to be large. Materials don’t just miraculously appear out of nothing. They can only be formed by solid, physical, REAL-WORLD processes. Some crystalline materials can form without pressure or heat. Olivine simply is not one of those.
Several times I ave posted a link to the paper I base this thinking on. The authors did laboratory tests on the olivine in the Allende meteorite, which I’ve talked bout at great length. They determined – forensically, in my viewpoint = the pressures and temperatures required. They tested it to find out what range of pressures and temperatures were required. Then they turned that evidence into depths required – and that into a minimum diameter for such a body.
That paper was essentially what brought this entire topic up: how do materials requiring such pressures end up in outer space INSIDE rocks flying around?
The data/results are in that original paper. “Pressure-temperature phase diagram for the Allende meteor”. Google it. Warning: It it dense stuff.
In addition, my recent reading has turned up papers which acknowledge this requirement for processes deep within planets and which try to explain how mantle materials end up in space. They also point out about 60 different iron bodies have given us unique chemistry from what they see as 60 different differentiated bodies which have had their crusts and mantles removed. They propose that impacts have cratered the bodies until nothing was left but the iron cores. This is addressing the same lines I am, but I don’t see such massive erosion as being possible. In addition, they ask, if so much mantle material (olivine) has been removed, then where is it all, because it doesn’t show up in the meteorite history or spectrographic evidence of asteroids and comets? This is known as “The missing olivine problem”. Olivine DOES show up in some meteorites, but not nearly as many as their erosive process would produce. But that it shows up AT ALL is a problem that needs to be explained.
Thus, SOME astronomers acknowledge the problem of olivine
Steve:
I don’t feel that feel is a bad term for what we’re talking about. You could say the authors “conclude” or “speculate” or “know” or “prove”, but “feel” is concise and neutral.
Yeah, I haven’t read the whole thread, thanks for the link.
So the basis for the conclusion that the pallasites formed deep within a differentiated body is actual high pressure lab work.
And you are pointing out that no one has ever produced a computer model of an event that could “excavate” these materials from their formation depth within such a body?
David –
Yeah, it was lab work, and solid measured values about REAL physical processes. At least in ranges that they worked on, they now have real data. They then reasoned – without having to construct a model – that the pressure ranges and temperature ranges TELL them what can be. No model is necessary – only straightforward thinking.
You don’t need a model about 2 + 2 = 4. From past learning you know that putting the 2’s together gives you 4. In a lab, material X needs pressure P and temperature T to be in a certain range. When these conditions exist, the resultant is olivine. It is just cause and effect, not a complex system. Not everything is systems. Some things are straight cause and effect. A certain peak in a spectrographic readout tells you that hydrogen is present, and another that carbon is. It doesn’t MATTER what the system is. These peaks can exist in various systems.
With the olivine, instead of peaks of elements being present, the tell-tales are pressure and temperature, acting on a certain material, magnesium silicate. That is all the complexity, no more.
That in itself doesn’t answer everything, though. The system DOES matter, and olivine is PART of it. But within that system, the olivine manufacture cannot violate the basic straightforward individual process. Systems are collections>/b> of processes. But within the systems, the included individual processes must EACH flow according to its own “rules”, and must stay within its own limitations. The system thus is built according to those processes and according to the materials staying within their limitations. THESE are the “parts” to study to see how the system CAN work, and they DEFINE the system.
Especially in reductionist science, the parts all taken together are the whole. This is standard scientific investigation in our present time – to discover those parts. Without understanding how the straightforward parts work themselves, any attempt to describe the SYSTEM is, frankly, stupid and very premature.
And when a system is proposed without CLEAR and FULL understanding of ALL of those parts and groups of parts and processes and strings of processes – without knowing them all fully, the system proposed has to fail. No one can see the whole system without knowing how the individual parts and processes exist, are limited, and how they contribute to the system.
Deductive science is having a view of the whole and then letting that understanding guide our thinking of how the parts contribute to the system – projecting downward from the macro toward the micro. But that can only happen when the whole system is REALLY known. Such knowledge cannot exist YET about the system that is the planets/solar system/galaxy/universe. We have IDEAS but not genuine knowledge. We have what amounts to partial observations, and most of those are disconnected – meaning that the ideas about the whole are disjointed and cannot yet be counted on to be real.
When astronomers tell us that they already HAVE an understanding of the system, then the proof is in the pudding: They should NOT be wrong when they tell us that, for example, Vesta has a mantle and tits mantle is made up of olivine. BUT THEY WERE WRONG.
Oops! I didn’t double-check my formatting. Sorry about that.
Continuing but changing the focus…
Amazingly and mendaciously, NASA seems to me to have SPUN the Dawn Mission’s evidence about Vesta to say that the results proved them correct. But as I see it, that was a lie. I almost spewed when I heard them spin it. I can SEE clearly WHY they would spin a failure of theory and claim victory about the olivine on Vesta. The findings gave NO support for the Vesta-olivine-HED meteorite connection. No as in ZERO. In fact, the evidence now strongly suggests that all of that connection was a premature speculation and is no shown to be utterly WRONG. And here we are, four years later, and they are still talking about that Vesta-olivine-HED connection as if nothing had happened.
The Dawn mission was tasked with finding the olivine on Vesta. Outside mapping the asteroid and measuring other certain things about it, the olivine connection seems to have been the main reason for going to Vesta. But the mission showed NONE of the evidence that they expected to find.
That is a failure of theory. Paraphrasing Richard Feynmon on the Scientific Method, when the results your hypothesis predicts are not in agreement, THE HYPOTHESIS IS WRONG.
Someone’s head should have rolled. Someone should have fallen on his sword or jumped under the train/bus.
NASA cannot at this political juncture be found to be wrong. If they have a failure, Congress’ STRONG tendency is to give them less funding and rub their noses in it. So, they MUST make it look like they had it right all along, even when they are 180° off target on their predictions. Their very careers, individually and organization-wise, depend on putting a positive spin on all of it.
When the Philae probe to comet 67P almost flew off into space after the first landing attempt, but then eventually landed on its side and gave them only about 3-5% of the data they’d been hoping for, and only for a very few days, the Philae probe was a FAILURE. It sat giving zero results for MONTHS. And, miraculously, Philae “woke up”, a few days before perihelion.
I am going to put on my tin foil hat and say that I smell a rat. Did Philae REALLY wake up? I am going to suspect some chicanery and spell out my suspicions that perhaps Philae never woke up at all, but some people conspired to make it LOOK like Philae woke up. There is all the incentive in the world to fake it: A failure after all those months and years is “NASA wasting money”, which NASA has dealt with in the past. And what was the result in the past? Severely reduced NASA budgets.
It seriously would NOT be so difficult to fake the data coming in after Philae “woke up”. It’s all electronically transmitted from sensors, in principle. Substituting fake data – is this even a possibility? I actually think so. In my experience from 25 years ago in R&D I learned how data is produced. And I learned how WRONG data can be produced, by having sensors in the wrong places, having the sensors adjusted wrong, etc. If such factors are not seen right away, wrong data can cause people to choose wrong directions for their next tests and experiments.
Computer capabilities and the savviness of programmers are both VASTLY beyond what I dealt with in about 1990. After Philae ended up on its side and looked like it was a dead rat, then if someone was tasked by supervisors with making it look like Philae woke up, I am sure that NASA has people who could do that. NASA is in control over what sensors are used, how they are adjusted, where they are placed, etc. As such, they can introduce false sensor readings into the mix – AND NO ONE WOULD BE THE WISER. The individual(s) may not WANT to, but I am sure they could do it. If they DID, then they would deliver results that would fall into line very cleanly with the PRIOR expectations of people on the project. If the Philae data DO align closely with prior expectations, that would be, IMO, at least suspicious.
The public spin put on the Dawn Vesta observations is so utterly opposite of what was actually accomplished and discovered that I have to wonder how much truth is in things NASA tells the public about either mission.
I DO NOT WANT TO BE RIGHT ON THIS. I want them to succeed, but I want them to succeed legitimately. Anything that looks like success – real or fake – WILL allow Congress to “feel good” about the NASA programs and about keeping current funding or even raising NASA funding. Failure will put a very bad taste in Congress’ collective mouth. When I SEE them lying about Vesta and its discoveries, how can I trust them when miraculously Philae “wakes up” – just when it can give some good results? Something seems crooked in Denmark. That is awfully serendipitous, that success happened right when the failure would show up most clearly – and without any intervention by NASA people. That is the story we have been told. Right now, I don’t have any confidence that the wake-up is real, or that any data since the wake-up is real.
So, Steve has another tin foil hat he wears. (BTW, for the record: I have never ONCE suspected that the Apollo Moon landings were faked.)
Steve; Not the right thread but: A bit of sad news. My meteor-maybe is now a confirmed meteor-no-no. A close call, but no. As was predicted by everyone but me, DOH!
Jim – Don’t feel bad. Nobody would have ever come up with the term “meteorwrongs” if a lot of people hadn’t misread what they had. You aren’t the first, and you won’t be the last.
If it were me looking for meteors, I’d be looking primarily for the “fusion crust”. I don’t think all of them have it, but that is the one thing that would catch my eye.
Live and learn!
The authors who looked at the Vesta south pole overlapping craters and determined that Vesta’s olivine wasn’t in the craters have also concluded that the basic theory of rocky planet formation needs to be overhauled. And their reason is exactly the thing I latched onto in the beginning of all of this. And my conclusion at the very beginning was that they had the whole planetary accretion thing wrong, from the ground up. The group of scientists put out second paper last July titled “Asteroid Vesta to reshape theories of planet formation”. I heartily agree. I think they will all probably focus on the later stages of planetary formation, so I don’t expect them to cover my initial concerns regarding too little gravity, too little pressure, too little heat. http://dx.doi.org/10.1038/nature13499
I am pleased just to know that my thought processes were not crazy.
The authors made a bit of a big deal about there being far too much material removed, compared to the amount accounted for in (I am assuming) asteroids and meteorites. The difference is about 15-fold. But they shouldn’t be. The pyroxene tensile strength is quite high, and when it broke, the energy needed to do that SHOULD have caused the ejecta to exceed the escape velocity of Vesta (0.35 km/sec, or 777 mph – about the speed of sound at sea level on Earth), meaning a whole lot of material would have gone all over the Main asteroid belt, and much of it should have landed on other asteroids – not even COUNTING how much would have spiraled down onto Jupiter.
The diameter-to-depth ratio of the craters Veneneia and Rheasilvia are quite low. To me this indicates two things: A low impact velocity and generally weak and not terribly dense target materials. The former I estimate because gravity is said to not be a factor in impact cratering. I got that from the guy in Europe who did the high-velocity lab tests with the target material held vertically. When materials are sheared or broken via tensile forces, the immediate energy release makes the materials accelerate. F = ma means that the force that is sufficient to break the rocks will STILL be being applied just after the breakage – pushing the ejecta, at a too-high acceleration, so much that most of the materials would NOT have landed back on Vesta. Even with a LOT of target material removed, I predict that when we land on Vesta, we will not find a terrific amount of regolith.
The not real dense target materials I estimate based on the fact that though the craters are over 400 km WIDE (90% of the entire width of Vesta), they are not deep. This suggests that much more of the energy went laterally in comparison to ones on Earth. But also that the impact velocity had to be relatively low. A high-velocity impact would have the same diameter-to-depth ratio as on earth. If 67P was any guide, ejecta velocities would be about 35-40% of the initial impact velocity. To exceed escape velocity, thus, the impact had only to be over about 1-1.2 km/sec. That is NOT a high velocity impact. It is slower than most bullets.
I could be wrong on the low density target materials, but that is my impression after dealing with this for a good while.
The bottom line? Vesta is not the source of the HED meteorites, even if Vesta’s structure is helping shoot down the planetary accretion theory. And all of this is one step closer to finding out if accretion is or isn’t how asteroids (meteoroids) which threaten Earth came to be.
Steve; The thing about the stone was the fact that there was ablation on the faces. A definite rind, but that could be of terrestrial origin. Maybe next time.
Steve –
Per your 3 responses.
1. We have observed a system with what the smart guys describe as having a lot more dust than it ought to have. Story last year was about Beta Pictoris. They are blaming it on cometary collisions. The question is obviously why that system and not others?
http://www.forbes.com/sites/bridaineparnell/2014/03/07/rapid-fire-comet-collisions-create-planetary-system-with-the-potential-for-life/
2. An abundance of uranium may or may not go critical. The trick is how quickly it goes critical. You do know there were at least two natural reactors over the last couple billion years? Both were in the vicinity of Gabon in Africa. A reactor that goes critical essentially self-sustains a reaction. The trick to making it go boom is to slam it together very quickly, which it tough to do inside a solid body. My guess is that the worst an over abundance of uranium would do should it go critical would be to heat up the core. Run away for a while and you simply melt the body. Final problem with this is how does such an overabundance gather in the first place? After all, uranium is formed via supernova explosions. Link to a math workup on how much is required to blow up a planet follows. Looks moderately reasonable.
http://www.ebtx.com/theory/uranium.htm
3. Out of plane stuff is a big deal. Total mass of the entire asteroid belt is round 4% of the total mass of the moon, and the vast majority of that is in-plane. The Jupiter Trojans have been suggested as having equivalent mass, which orbits around the L-points of Jupiter’s orbit. So within the orbit of Neptune, you have say 10% of the total mass of the moon in asteroids and comets. If you blow up a moon-sized body, where is the 90% of that mass that is no longer in plane? Larger bodies produce more mass. A Mars-sized body has about 10x the mass of the moon. Earth has about 10x the mass of Mars. The bigger explosion you have, the more stuff you eject out of plane. Where is it?
All for now. Cheers –
Agimarc –
1. I apologize for being such a tough audience so many times. But the Beta Pictoris article has me cringing. COMETS? They see comets? Comets colliding? No asteroids. Comets. They see carbon monoxide and conclude comets – because WHY, exactly? Sounds like they went down their list of CO possibilities and MIGHT have jumped to a conclusion. Comets? REALLY? Like coming in from the Oort cloud comets? Are they going to write up next week that Beta Pictoris has an Oort cloud, too? NO. Planetary formation – according to the standard solar nebula paradigm has dust clouds going in somewhat circular orbits – not in elongated cometary orbits.
If they called them carbonaceous chondrites (a type of asteroid as you know), collisions would include carbon, yes?
Boy, you come up with stuff that stretches my brain. Hahaha – For that I thank you, but sometimes it HURTS…LOL
Googling “comet ‘carbon monoxide'” pulls up a few things, but mostly it is very recent stuff, Dawn mission and Rosetta mission stuff, angles I’d not had to look ito before. But it SEEMS like the carbon monoxide is a new toy, sort of. Even though the article pointed out that CO only can last about 100 years in the presence of UV (which UV is not spelled out), carbon monoxide was supposed to be part of the “black organic material” on the outside of some comets. That seems contradictory. Any CO would have needed to be INSIDE to be protected from UV. Or, as they ad hoc explain, the CO “must be” being replenished. That is another Goldilocks condition they pull out – and which often end up being accepted without challenge.
With only that 100 year life span out there – ESPECIALLY with comets (again Goldilocks condition) hitting each other and smashing themselves to smithereens.
Honestly, this sounds totally like them sitting around a coffee shop comparing possibles, and then accepting the combination of speculations that make CO readings possible.
I am a tough sell on this one. All I see is guesses mixed with guesses, and because they are the astronomers we are supposed to accept their guess souffles as correct. It all may sound reasonable, but I could go back in science history and point out hundreds of cases of reasonable ideas that were accepted for a long time and which we now laugh at. I was just reading something from the 1880s that all sounded solid at the time, but that I can’t believe they could have thought that such speculations were SCIENCE. Ditto with this.
That is NOT all off the top of my head. I LOOKED at nearly ten papers and articles, and the connection with the Beta Pictoris idea is way too tenuous for me. It is something to consider, but for now it is just hypothesizing, IMHO.
I wish the science mags and popular press woud STOP printing scientists’ speculations as if they are true.
2. From the link: “The basic idea is … If a large concentration of uranium existed at the earth’s core … and it went critical … how much would it take to accelerate 1/2 of the earth’s mass to escape velocity (25,000 miles per hour)?”
WRONG assumption!
It not only takes moving the mass up to escape velocity, but it ALSO MUST break apart the structure of the Earth, exceeding the “maximum unit stress” of the materials within the Earth. The materials are not all sitting there loose!
This assumption will TOTALLY come up with a number FAR too small.
Hell, I’d like to see a smaller number! It would make my thinking that much more likely! But I can’t go with people’s ideas when the people seem to know NOTHING about materials and their “mechanical strengths”.
…The guy got on my bad side there, right off the bat… They came up with ALL that they thought would apply to the problem – but their utter ignorance of materials and their strengths means that the rest of the calculations are GIGO.
Cohesive forces are STRONG in many materials. Even in liquids it is called “viscosity” – the resistance to flow. And in the fluid mantle materials, which are silicates and more.
Then you have to add in FRICTION, of the materials to each other.
Then you have to add in MECHANICAL LOCKING, like when rough surfaces “grab” better than smooth surfaces.
NONE of those THREE extra conditions/characteristics is even quantifiable. Cohesive forces can’t because the pressures and temps are unknown (though guessed at). Friction? Friction to overcome is ALWAYS connected with normal pressure, so if pressure is not known, neither can friction be known – and it is going to vary a LOT based on temps and pressures and viscosity – as well as inclusions, which I assure you DO exist down there. It is why olivine comes out with peridots and garnets in it, when it is extruded as magma. Mechanical locking? Who the hell KNOWS what kind of locking is down there? It is the bane of earthquake geologists, to not know what kind of “grab” exists in different sections of faults.
I haven’t even gotten to his 2nd paragraph…
Critical uranium — I think we may be using the term “critical” in different ways.
There have been 26 critical and super critical accidents at U.S. nuclear facilities – none of which required the uranium to be slammed together. One of the first, at Los Alamos in the 1940s, I knew about long ago, when some hotshot let two halves of a split hemisphere touch. BAD IDEA! He died 9 days later. No slamming was involved, and it only lasted less than 1 second. As I’ve read, most of the other people in the room ended up dying of radiation poisoning.
A China Syndrome melt-down event like at Chernobyl does not require the fuel to be slammed together – but I assure you that the fuel went critical.
From the link: BAD MATH!
“4/3 pi r3 = 1.23 x 1014 or …
r = [1.23 x 10^14 x 3/4 x 3.14159 ]-3 which is … of course …”
NO! MATH ERROR It should be r = [1.23 x 10^14 x 3/4 / 3.14159 ]-3
…When you transpose the PI, it has to go into the numerator…
This gives a value of 3.1×10^4, not 6.6×10^4.
Thus, where he finishes with
“6.6 x 10^4 meters … or …
134 kilometers in diameter … or …
84 miles in diameter”,
It should be
3.1 x 10^4 meters … or …
62 kilometers in diameter … or …
38 miles in diameter.
That is much less uranium than he erroneously calculated.
But with this value, he is way short for the reasons I gave before – the three additional factors he overlooked. And there are probably additional ones that I did not include, either. His 84 miles in diameter may be not far off the mark, because his two errors sort of cancel each other out.
Oops! Muphry’s Law does it again!
“…When you transpose the PI, it has to go into the numerator…”
Should read:
“…When you transpose the PI, it has to go into the divisor…”
3. “Out of plane stuff is a big deal. Total mass of the entire asteroid belt is round 4% of the total mass of the moon, and the vast majority of that is in-plane.”
To the first one, YES, out-of-plane stuff IS a big deal.
To the 2nd, see just below.
To the last, NO. If you look at the graph of the inclinations of the asteroids in the entire solar system, no, they are NOT in-plane, NOT AT ALL. Unless I am reading that graph wrong. I do assume that they took the data for all the known asteroids and plotted out only the orbital radii and the absolute values of the inclinations. I am sure there was no other way to plot them. I am sure that didn’t take much work to do after finding the data. So, I don’t think the graph is wrong.
In-plane? It’s not even the VAST majority. It doesn’t look like a SIMPLE majority of the asteroids are in-plane.
I found this:
“Past theories have suggested that the asteroids are remnants of a planet that was destroyed early in the solar system’s history. However, that theory is no longer held in much regard […yaddah yaddah yaddah…], for if all of the asteroids in the belt were combined, they would form a body less than 1500 km (932 miles) in diameter — less than half the size of Earth’s moon, and so there is not enough material to make a planet.” — http://burro.astr.cwru.edu/stu/asteroid.html
That is from Case Western Reserve University – no slouches there… So I will accept the numbers…
But, at the same time, that is only the ones in the Main Belt, and their mass together would be <1500 km. Let's use 1400 km. The Moon is 3,475 km in diameter.
The 3D ratio is (1400/3475)^3 = 0.065. Close to the 4%, but about 1.625 bigger. But it is also not all of them. Certainly the Trojans of all the planets should be included, plus the Hungarias, the Cybeles, and the Hildas. And should we even consider any of the moons of, say, Jupiter or Saturn? Let's not, to be conservative.
A ballpark figure might be to add another 0.005 – a half percent. Perhaps 7% then of the Moon's mass.
So, how to account for mass, say, the equivalent to the Moon? The Moon is your guess, and we will go with that. I think the planet was possibly bigger, pushing Mars' size. There is no reason to think a planet within Jupiter is going to be way different from the ones that exist now. But let's stay with the Moon, to be conservative.
Where is the other 93%? Right?
As close as it might have been to Jupiter, how much would Jupiter sweep up?
Well, first of all, this is not some Hollywood movie with the planets all lined up for a sweet fly-by – all at closest approach. Jupiter was just as likely to be on the far side of the Sun, yes? Hold that thought for a second…
The Sun is where the Sun is. How much would go toward the Sun? Not half, because 90% of the mass would go out of volume within 20° of the plane. About 1% of the total in-plane fragments would be immediately at risk of going straight into the Sun – or within a few thousand orbits – about, say, 10,000 years.
. . .
But let's stop right there for a moment. If ~90% goes out of plane, and if the missing mass is ~93%, those two numbers suggest that if such a thing happened, then the two numbers don’t disagree by very much. (In that case, the argument is to FIND the mass out there, out-of-plane, yes? One of your questions, but can we come back to it later? I can tell you now, though, that I don’t see a problem…)
…
Whatever is close to in-plane but more tangential gets no easy pass. If they are near in-plane, they will STILL end up in elliptical orbits. Why? Because in one tangential direction the added velocities (additional to their initial orbital velocity) will mean that the tangential ones go into higher orbits, which will mean more elliptical orbits. In the opposite direction, their velocities will be subtractive of their initial orbital velocities. This, too, will mean more elliptical orbits. Lots and LOTS of perihelions and aphelions. Those that aim somewhat more inward will certainly be more elliptical, and those aimed somewhat more outward, same thing.
So, one way or another – due to heading or velocity – you will have all of the fragments of the near-in-plane objects on more elongated/elliptical orbits than the progenitor, yes? And what would that mean? Orbit-crossers. A high incidence of impacts on planets and moons, and in a fairly short time window. The inner planets and moons out to at least Jupiter and perhaps Saturn would be at risk of cratering. And they are NOT all in-plane, ven if they are close. It would be like a shotgun blast – spread out up and down, as well as side-to-side. Even moons on tilted orbits would be targets.
Planets and moons farther out would see less cratering, because the spreading out of the debris would make missing the outer planets more likely. But, I would expect also that when they DID get cratered, the outer ones would be more likely to have the initial fly-by as a one-time event – meaning ONE SIDE cratered and one side much less so. With the larger, longer orbits of the planets and their moons, they would be harder to hit. And with the debris spreading UP and DOWN, too, this makes for a lesser chance of hitting. But there is so much debris, that few targets get missed completely.
Still talking about the ones fairly close to being in-plane – what about the ones that aim more directly away from the Sun? How far OUT would they go? That depends on the velocity imparted by the explosion, wouldn’t it?
I can tell you one thing – the force would be MUCH greater than simply escape velocity. WHY? Because once the pieces fly out, the center of gravity may still be in the the same location, but there is no MASS there anymore. And every second, the void in the center gets more “void-y”. (And the pieces are all flying out of where the explosion took place, not from where the planet was GOING to be in its continuing orbit.) The main force applied would be to BREAK the planet, not to accelerate the fragments. And when the break came, the REMAINDER of the explosive force doing the breaking is THEN applied to the fragments.* THAT would be what the guy at that link and his calculations would be dealing with – the material JUST after it is no longer an integral planet. And that is the RESIDUAL force, after it was resisted by the planet trying to stay together. So, there would have to be MUCH more than his numbers suggested.
* As I said earlier, this is what DOES happen when materials break.
. . .
[An aside…]
In looking up the total mass of the asteroids, I found this:
“Editor’s note: Even with more than one-half million asteroids known (and there are probably many more), they are still much more widely separated than sometimes seen in Hollywood movies: on average, their separation is in excess of 1-3 million km (depending on how one calculates it).” — https://solarsystem.nasa.gov/planets/profile.cfm?Object=Asteroids&Display=OverviewLong
(With the Moon 400,000 km away from Earth, you are talking about the average distance being FIVE times that.)
THAT is a goody factoid. Using Newton’s formula for gravity, then, the average force between any two asteroids is the first mass times the 2nd mass times times G and then divided by 2 billion meters. How much gravity between two asteroids, then on average? Not freaking much. (That goes to my original point about too little gravity. If NOW< after the pieces have had 4.6 billion years to draw together, their distances are 2 million kms, how FAR apart were they originally – and when they were SMALLER? And in the original 3D nebula?) The deciding factor is not the gravitational attraction, but their momentums in skewed directions as they fly past each other – millions of kms apart.
[end of aside]
. . .
So, where IS all of that? Why haven’t wee SEEN it? Well, Ceres and Vesta and Pallas weren’t seen until 1801, 1802 and 1807. And by 1910 we’d only found about 702 asteroids, out of millions. And where were we LOOKING? In-plane.
As of just before this TERRIFIC YouTube video was made in 2012, there were 588,992 asteroids known. https://www.youtube.com/watch?t=41&v=xJsUDcSc6hE
I am GOBSMACKED at that video. WOW. The narrated information is terrific, too. At the same time, I am not SURE from it if the search for asteroids has looked very far up or down from in-plane.
From reading up on the WISE and NEOWISE missions (2010-2014 so far), thus far I can’t find out how much of the out-of-plane regions were looked at for asteroids. So far there doesn’t seem to be much info saying so. Though NEOWISE only looked for NEOs, it necessarily had to have been looking for them in-plane or very near. Out-of-plane ones cannot threaten Earth, due to the 3D movement and the Sun being a focus for their elliptical orbits. Out of plane ones would not come across the ecliptic at our orbit. WISE is said to make a “full sky” map, but almost all of the info seems to talk about features out of the solar system – black holes, brown dwarves, mapping the arms of the Milky Way, etc. Every sky map associated with asteroids seems to only show the ones near the ecliptic. Though they did find many asteroids, so far nothing says how high up the asteroid search went. They DO have 16 images of every part of the sky, at different wavelengths. I can’t find detailed enough info. And every map of asteroids only shows them from up above looking down, in what for all intents and purposes look like 2D maps, even the animated maps.
I am sure the motions of any fragments that went UP would be VERY weird – some kind of pretzel shaped orbits to start. This due to the initial orbital velocity and direction, and then add in a vertical vector, with the Sun being at one of the focii of the resulting (elliptical?) orbits. And if I am not incorrect about the in-plane ones that reached out to near where they think the Oort cloud is, before beginning to head toward the Sun, then those had to get there fighting the direct retardation force of the Sun’s gravity. If the explosion was that powerful, then fragments headed UP or DOWN with an equal initial explosive impulse would have probably gone even farther, since the Sun’s pull would not have been from the back but from the side. At the least the Sun’s pull would have been affected by the cosine factor, reducing the pull. But that SIDE pull initially would have done some weird things to the orbits.
Bottom line? I can’t yet find enough info. I intend to, but am working on other things, and am not sure when I can really get into it.
So, YES, out-of-plane objects need to be found, or the XP idea is a dead fish.
Once again, sorry this is long…
I am averse to adding more to that, but think I should point out that there is a good overlap of comets and asteroids, based on various characteristics, not the least of which is having a tail or not. The idea of comets being “dirty ice balls” is long since a misnomer. 67P, for example is certainly not mostly ice.
I posit the basic idea that comets are essentially the debris that got thrown out away from the Sun – or in toward the Sun and which passed close enough to get slung out very far. SOME of those Sun grazers would have certainly gotten slung UP or DOWN. But most high-inclination comets I think would have been directly exploded up or down.
I also think that calling them comets or asteroids is misnomer. If the planet had water on it, certainly some fragments would retain the water as ice.
Scmitt et al 2015 “COMPOSITION OF COMET 67P/CHURYUMOV-GERASIMENKO REFRACTORY CRUST AS INFERRED FROM VIRTIS-M/ROSETTA SPECTRO-IMAGER” seems to suggest my thinking that comets are not dirty snow balls can at least sometimes be correct:
“The 3.2 µm band: The broad 3.2 µm band can be assigned to OH, CH, H2O, NH/NH2 and NH4+ chemical groups, molecules or ions. The nucleus temperature of 220 K renders negligible a significant contribution from water ice, which is marginally detected in area of the nucleus just emerging from shadow”. http://www.hou.usra.edu/meetings/lpsc2015/pdf/2092.pdf
Perhaps 67P is only called a comet because of its orbital parameters, not its composition. If it hardly has any ice, what is it?
I also think that regolith on asteroids and comets is explained nicely by the XP idea. If chunks and dust are thrown out in the same direction and at the same initial velocity, then it seems that the regolith materials could settle more easily than to be picked up out in space somewhere or migrated from a separate large body going at some random relative velocity, across the bow. Going at the same speed and in the same direction, there would be LOTS of time for the dust to migrate down onto the surface. NOT SO, with passing bodies. There would only be an instant of close approach, before the distance increases and the gravitational pull rapidly declines.
Regolith seems to be fairly ubiquitous – on both comets and asteroids.
I would even posit that regolith has fooled many earth-based spectrographs – as the olivine dust on Vesta did – by showing up the regolith materials instead of the underlying solid body materials. As such, what are comets and asteroids really made of? Did water vapor drift down as snow onto bodies that spent most of their time far out in the solar system and then fool the astronomers?
Probably not! I am probably wrong! But for me it is worth thinking about.
Steve; I bet you had too soak your fingers in ice after that last round of postings. Very interesting stuff.
‘@Steve –
The reason I mentioned Beta Pic was that it was the single system observed with more dust then it should have. That the smart guys suspect comets is as you suggest, it is the newest big thing, as the only CO emissions we have observed are from active comets, ergo comet smash. Proven? Hardly. Best guess? Maybe.
Still, in over 2000 systems with planets in place or forming Beta Pic is the only place with more dust than it ought to have, which lops away at the notion of an XP. Cheers –
Thinking out loud about comets and their outgassing, which is the source of their tails… How strong is the outgassing flow?. . .
Hollywood movies give the impression of this outgassing as being a violent event like pressurized steam coming out of a pipe (another Hollywood convention). What was the movie with guys getting blown out into space? I am thinking that if they have maneuvering jets, the thrust from the jets is very likely many times as powerful as the outgassing.
The first thing that comes to mind is to ask how deep within the comet it is being created. It is, after all, simply warming of water and other “volatiles” that can vaporize. Water, especially, in a vacuum at those temps would likely never go liquid – but would sublimate straight to water vapor. So how deep can the warming penetrate?
Fusion crusts on meteors WITHIN the atmosphere occurs only to a depth of about 3 millimeters. Ablation – melting of the solid rock – only occurs in that same 3 mm, before vaporization that is seen as a glowing, fiery ball and tail.
These are processes that take many hundreds of degrees – about 2000° C or so, if I remember correctly. And still the heat drops off very rapidly within the body of a meteor with strong PRESSURE and TURBULENCE making the heat transfer REALLY high. Contrast that to essentially zero outside pressure and no outside gases to be turbulent. All the comets have is a SLIGHT internal pressure of the volatiles in the cracks and pores – each one of which has to warm up on its own. We are talking of individual small volumes of volatile gases here. Volatiles in big cracks will be outgassing from smaller cracks and pores in the side walls of the large cracks. (And just a little way inside the direct rays of the Sun can’t penetrate, so no outgassing would occur more than a few feet inside the large cracks. Only when the rotation of the comet lines up the crack with the Sun – which only happens for a few seconds or minutes.)
All of this suggests that the heat of sunlight on comets in space can only penetrate a short distance under the surface of a comet. That may not be true, but it seems consistent with observations of the fireballs we call meteors in the atmosphere. Silicate rocks, as 67p/Churyumov–Gerasimenko certainly seems to be, are NOT good conductors of heat, and in fact are fairly good insulators. They warm up slowly and cool off slowly. BAD heat transfer.
I know from my interest in climate that the energy density of sunlight that reaches the top of the Earth’s atmosphere is only 1367 watts per square meter. This translates into about 127 watts per square foot for us Americans – a bit more than the energy of a 100 watt incandescent bulb. This is about 127 joules. So, anything at 1 AU will have the same energy density on its surface. As comets pass the orbit of Earth, then, they are receiving about 127 joules per square foot, and the rotation means that the angle is continually changing (any angle excpet 90° means LESS intensity per square foot). That 1367 is all frequencies of light. At the surface about 53% is infrared, the light energy that heats things up. If we use that 53% value, then the amount available to heat a comet at 1 AU is about 725 watts/sq meter, or 67 watts per sq foot. (A sq meter is about 10.8 sq feet.) So, you can see that the intensity of the energy is pretty damned low.
And if this low intensity of EM energy is impacting the surface of a comet, and it only goes maybe 3 mm deep (1/8″), the intensity of the heating inside the comet is very low, almost zero – even over time (especially because they don’t spend much time at 1 AU or less). I have to think that the warming doesn’t go at all more than an inch or two deep. And the 3 mm is a conservative value, since the vastly greater heat applied during atmospheric entry of a meteor only goes that deep, versus the very low intensity heat applied to the surface of a comet in space at 1 AU. The outgassing, then, would seem to be very superficial. 3mm thick for a spherical comet the size of 67P (4200 meters across) represents only about about 0.0002% of the total volume. We are talking a VERY small total capacity here for outgassing.
This leads me to wonder how violent the outgassing velocities can possibly be. Certainly nothing like Hollywood depicts. VERY tenuous gases, released rather slowly. 67 watts of infrared is incapable of warming rapidly. Flow is dependent on F = ma. Or a = F/m. But F comes from pressure, and outgassing into a vacuum means that very low pressures can result in outgassing. Therfore, as SOON as the delta-P is enough to push some gas out, it will. It can’t store up pressure until it builds up to go BOOM. it is like a pressure relief valve that is set to WIDE OPEN setting. Pressure can only exist when there is resistance to flow. Low release pressure, low masses of volatile gasses – release of the gases internally is not done all at once, but instead it seeps out of each pore. Yes, the total area of a comet can be large, but for the most part only the sun-side is outgassing at any given time. The outgassing has to come on slowly, as the comet approaches the Sun – ANOTHER reason that the outgassing can only occur slowly. It is a gradual process, not a rapid one. Yes the slope of the curve increases with proximity to the Sun, but from moment to moment the outgassing increase can’t be great. But that “wide open pressure relief valve” means that each pore outgasses at the lowest possible delta-P.
The escape velocity of 67P is about 1 m/sec, or about 3 feet/sec – a walking speed. Exceeding this escape velocity threshhold is not difficult at all and requires VERY little energy. It also produces a very low outgassing pressure – probably on the order of 0.01 psi pressure differential, average. Even at such low pressures, the outgassing is enough for SOME of the gasses to exceed the escape velocity.
agimarc –
“Still, in over 2000 systems with planets in place or forming Beta Pic is the only place with more dust than it ought to have, which lops away at the notion of an XP.”
Not clear what you are saying there… But interested in what you Do mean.
Yeah, they connect the comets only because of the CO – that is the kind of thinking that to me is not scientific but just jumping to conclusions – and then putting it out for the world to see makes it even worse science. We might as well be back in ancient Greece, where they logic-ed out everything and got it all wrong. Earth, air, water, and fire stuff… Aristotle and his thinking messed up thinking for 2000 years.
‘@Steve – ran out of time last night. Second point on uranium.
We are using critical the same way – a sustaining reaction where the products of a fission produce additional fissions. Let it run away and things go boom. Controlled criticality is how you generate heat in reactors. Some (most?) of the accidents have been runaways, which is what you need for and explosion.
Did a back of the envelope calc on total mass of uranium in the earth. Assuming I didn’t completely botch the calc, we end up with a ball around 124 miles (statute) in diameter. If you are only interested in U235, as 238 doesn’t explode, that number decreases to some 38 mi in diameter. Source for the total mass is a paper on using Geo-neutrinos as a measuring device. Link to paper follows: http://arxiv.org/pdf/hep-ph/0501111.pdf
This is a long way of saying that looking at a nuclear trigger for an XP needs a lot more uranium (or thorium or pick your poison) than we have. The fissionable metal needs to be concentrated in the absence of moderation so that a runaway reaction takes place. And if you start postulating exploding interlopers with higher concentrations of heavy metals, we run smartly into the chicken and egg problem. How do you end up with the additional heavy metals in the first place?
Like I said previously, we have seen natural reactors on the earth that went critical but did not run away. http://www.scientificamerican.com/article/ancient-nuclear-reactor/
If you are talking about hydrogen explosions, we already see one of those. Actually there are three examples – Sun, Jupiter and Saturn. Only one of those is actively fusing. The other two give off more heat than they receive from the sun but are not massive enough to sustain a reaction.
Final point, in the event of excess heat on a rocky body, it simply melts and will not fly apart unless it is spun up to the point where it the centrifugal force is greater than its escape velocity at the equator. As angular momentum must be conserved, what spins it up? Cheers –
It may be belaboring the subject of olivine and its window of pressure, but this from Wikipedia about garnets I thought is pretty illustrative of what materials the different pressures under the Earth create (especially since I started the entire subject talking about peridotite (which was present with olivine in the Allende meteorite):
agimarc – I agree with you on the U-235 vs U-238. I had that in my mind and didn’t get around to including it for some reason.
But are you sure about your ratios of U-235 and U-238? The percentage of U-235 in my head is 0.7%. Yep, Wiki gives it as 0.72%. (No, I don’t run around with all those isotope percentages in my head – I am not THAT big of a geek. That was something I’d read several times from my interest in Thorium reactors…) If 124 is the diameter of U-238, then for a volume of .0072 of that, I come up with a radius of 11.97 or a diameter of ~24 miles.
“The fissionable metal needs to be concentrated in the absence of moderation so that a runaway reaction takes place.”
You lost me. A ball of solid uranium 24 or 38 miles in diameter doesn’t constitute concentrating it? Cadmium is a common moderator in nuclear reactors. Is the U-238 considered to be a moderator?
A study last year discussed their discovery of the inner inner core of the Earth (yes, two “inners”). http://www.dailymail.co.uk/sciencetech/article-2946138/Journey-centre-Earth-Scientists-planet-s-inner-core-core-own.html it talked about geomagnetism coming from iron in the inner core aligning differently from the iron in the outer core, but it did not talk about how big the inner core is. It also did not even mention uranium, which makes no sense. But a 2003 article at http://www.spacedaily.com/news/earth-03k.html talks about a 5 mile diameter inner inner core of uranium.
I don’t know where you got your 124 mile ball of uranium (I tried, but everything was directed at uranium in the crust). If there is that and then there is a 5 mile ball inside the other, what could that mean?
Uranium melts at about 2,070°C. The inner core and outer core are said to be at 5700-6000°C. So any uranium in the core is going to be molten – unless the pressure keeps it in some quasi-crystalline state.
According to two sources, the uranium in the MANTLE keeps the outer core melted. If the outer core is melted, then convection is going to drive the U-238 to the inner core, and the U-235 should follow and form a shell around the U-238. I mean, differentiation is all about heavy materials sinking and lighter materials floating upward. That is basic geology’s meme.
If the U-238 and U-235 don’t sink to the bottom/center, can you explain why not? And with a molten mantle, too, any uranium in the mantle is doomed to sink down to the core. The reason uranium is semi-rare on the surface is supposedly because the uranium sank during the differentiation. No? Yes? And I’d like to know why n 4.6 billion years the molten uranium isn’t concentrated at the center. If it is fluid (which the temperatures strongly suggest – and the scientists maintain), then it should have been convecting downward for a very long time.
I am missing something, because how can it sink and still not concentrate the uranium?
Article tying the YD cooling event to an impact is up at WUWT. Let the good times roll. Cheers –
http://wattsupwiththat.com/2015/07/27/younger-dryas-cooling-event-said-to-be-comet-related/
I have started a post…
(Up all night on this on, agimarc. I didn’t see your comment until like 1:00 am, and went right over to WUWT…)
GEORGE –
This comment over there really caught my attention:
“LT” is the guy’s userID.
James P. Kennett, et al. Bayesian chronological analyses consistent with synchronous age of 12,835–12,735 Cal B.P. for Younger Dryas boundary on four continents doi: 10.1073/pnas.1507146112 (Paywall)
http://www.pnas.org/content/early/2015/07/21/1507146112.abstract
Trent –
Just in terms of how much mass is in the steroids, I have to post the question “How many is the mass based on?”
I want to re-post the link to that asteroid discovery video. At the end, I’d like you to VISUALLY see how many of the buggers are there. He points out that each PIXEL is 500,000 km.
https://www.youtube.com/watch?t=41&v=xJsUDcSc6hE
When people talk about the asteroids only comprising X% of the mass of the Moon, I have to ask when they did their numbers, because this is the numbers at different points in time (from the video and I grabbed the last number in each year):
1980 – 9,425
1985 – 12,214
1990 – 15,924
1995 – 26,748
2000 – 123,114
2005 – 343,671
2010 – 548,914
2013 – 588,992
When Tom van Flandern died in 2009, at the end of that year 504,118 were known. Since then the number has increased 16%, adding 84,874. That is 3 times as many ADDED as we knew about in 1995.
So, my thing to you is partially to LOOK at that later portion of that video and see all those flying around, and imagining that MAYBE might they have came from an XP. Don’t agree. Just imagine.
They are NOT all in the same plane, and each pixel may harbor quite a few asteroids. I suspect that they do.
To have THAT many out there for 4.6 billion years and still are surviving, that is amazing. Impossible? If the Oort cloud has comets “bumped” into sunward orbits, with the Oort cloud being 360°x360°, wouldn’t one think that the asteroids would have had most of them bumped sunward and crash into either Jupiter or the Sun by now?
In the video I was struck by how CLOSE so many orbits came to Mars, and how FAR they were from Jupiter. Obviously, Jupiter swept up the ones close and so did Mars. But the ratio of the width of the two spaces, really illustrated to me the difference in gravitational pull. And if these may happen to be one day found out to be the remnants of an XP, this video illustrates how little protection Mars had.
Whenever they were created, some asteroids crossed Mars’ orbit and whacked into it. Some crossed it without collision and managed to stay clear all this time – 4.6 billion years. Or maybe 20 million? Or less? There are definitely panels in a couple of Egyptian temples that show an extra planet. So, maybe 3,000 years ago? Hahaha probably not, but what is that extra planet doing there on those hieroglyphic walls?
Steve Garcia,
I just punched that table of yours into Excel for a bar chart and it is absolutely wild.
The jump between 1990 and 1995 was almost a doubling.
The jump between 1995 and 2000 was almost a tripling
And again between 2005 and 2013 almost another double.
We are living science fiction as science fact.
‘@Steve –
The larger ball came via the paper I linked which estimated total uranium on the entire planet at some 80x10exp15 Metric Tons. They got that estimate looking at what they called geo-neutrinos from fission of uranium and its isotopes.
Screwed up on the smaller ball. You are correct at 23 statute mile diameter sphere on the U235. Larger volume is 124 miles diameter.
The reason it doesn’t concentrate together is due to convection in the outer core and the mantle. Convection is how the internal heat is transferred outwards. It is what drives the mantle currents, plumes and other forms of upwelling. As it is liquid (or if you prefer, plastic) and highly viscous, it cannot concentrate. The inner core started out liquid and transferred its heat outwards, mostly via convection until it got cool enough to solidify.
Explanation as to why the two isotopes don’t separate: Too little difference between the individual masses. Remember these don’t exist as metal. They exist as molecules of rock, further hampering any tendency to separate via mass.
Bottom line is you don’t have enough elements that can concentrate and explode to drive an XP. Cheers –
Observation on non-planetary objects. It continues to amaze that the more we look, the more we find, especially inside the orbit of Neptune.
I would submit that an effort to add up the mass of known KBOs will far outweigh everything inside the orbit of Neptune not attached to a planet. Here’s a good place to start.
http://www2.ess.ucla.edu/~jewitt/kb.html
Would also submit that what is still in the extended Oort Cloud may not be what our sun started out with. The problem is that the solar systems regularly interacts with other stars, some passing well within the supposed boundaries of the Oort Cloud. These sort of close approaches take place in the range of hundreds of thousands of years or so. Approach distances are within a tenth of a LY. If all stars start out with an array of Oort like objects, won’t these get mixed, matched, captured and scattered over multiple encounters during the billions of years? This leads directly back to the Fred Hoyle panspermia suggestions. Cheers –
http://www.iflscience.com/space/star-passed-less-light-year-earth
Trent – Yeah, way cool.
Did you happen to look at the video? I was WOWED by it. SOOOO many… At the pixel resolution of 500,000km/pixel, it looks kind of solid, all the way across the Main Belt.
agimarc –
Just discussing, I guess. . .
“The reason it doesn’t concentrate together is due to convection in the outer core and the mantle. Convection is how the internal heat is transferred outwards. It is what drives the mantle currents, plumes and other forms of upwelling. As it is liquid (or if you prefer, plastic) and highly viscous, it cannot concentrate. The inner core started out liquid and transferred its heat outwards, mostly via convection until it got cool enough to solidify.”
Convection, IMHO, is given a lot of street cred that I don’t think it deserves.
Yes, convection exists. But consider the things convection has going for it and things it had going against it:
FOR:
1. Gravity
2. Density differences
3. Fluids are non-crystalline and therefore can flow
4. The more brownian motion (heat energy) present, the more readily fluids flow
AGAINST:
1. As one fluid rises, it had to replace the lighter fluid above it
2. Viscosity – resistance to flow
3. Pressure – the higher the pressure, the higher the friction (the higher the viscosity)
In a hotter environment viscosity is lower.
In a higher pressure environment viscosity is higher.
So which wins out, in this tug of war? I am not sure.
“Explanation as to why the two isotopes don’t separate: Too little difference between the individual masses. Remember these don’t exist as metal. They exist as molecules of rock, further hampering any tendency to separate via mass.”
Thinking out loud… Cascades of centrifuges are THE method of separating U-235 from U-238, by reason of density. But it is done when the uranium is in gaseous form, as uranium hexafluoride. This lowers the viscosity by a LOT.
Uranium in the core – as is everything there – is a liquid. I do not know if the conditions of ultra-high pressure is sufficient to allow convection of the liquid uranium.
I know that in testing the olivine in the Allende meteorite, they needed a super-high pressure laboratory anvil in order to simulate the pressures, just at the depth of the upper mantle. We have a hard time getting much beyond that pressure (about 22 Gpa – or 3 million PSI.
Something in my head says that when huge pressures exist, materials not only change physical characteristics, but that they do unexpected things. The core pressure is said to be about 360 Gpa – about 16 times as high as the lab anvils.
Even “only” 3 million PSI is so far above pressures and materials strengths that I’ve dealt (about 10 times more) with that I can hardly fathom what happens to materials. 10 million PSI is the target for fusion. But 360 Gpa? That is pushing 50 million PSI. What this does to materials I haven’t a clue. I am thinking of actually stripping electrons and going all plasma, but that probably is really wrong. I DO believe it is enough to add a super lot of temperature. Enough to even cause fusion or fission? Something in me says yes, but I can’t back that up. Pressure creates heat, and pressure alone creates fission. Massive heat causes fusion, if I read everything well enough (probably not). 50 million PSI is a NASTY level of pressure.
I am sure the pressure makes convection even harder. At the same time, there are billions of years for the flow to overcome any high viscosity. Which wins out? CAN convective flow separate U-235 from U-238 in a mostly iron core? Not in ten seconds and not in days or hours or years. But on the scale of ~4 billion years?
I will tell you THIS: It is a CLEAR geological understanding that plumes in the mantle are convection-driven, and the pressure there is well in excess of 3 million PSI, pushing 40 million PSI near the core. If mantle plumes are accepted to exist, saying that U-235 and U-238 – a density difference of 3 protons and 3 neutrons – can not convect, well I don’t think that is a correct assumption. That density difference is about the same as between iron and copper, or hydrogen and helium. I am pretty sure it is more than between warm air and col air.
This was published today,
a confirmation of some of Davias’ and Harris’ work,
“Approximately 790,000 years ago there were multiple cosmic impacts on Earth with global consequences. Geoscientists from Heidelberg University reached this conclusion after dating so-called tektites from various parts of the world. The research group under the direction of Prof. Dr. Mario Trieloff studied several of such rock glasses, which originated during impacts of asteroids or comets. The Heidelberg scientists employed a dating method based on naturally occurring isotopes that allowed them to date the tektites more accurately than ever. Their studies show that the samples from Asia, Australia, Canada and Central America are virtually identical in age, although in some cases their chemistry differs markedly. This points to separate impacts that must have occurred around the same time. The results of their research funded by the Klaus Tschira Foundation were published in the journal Geochimica et Cosmochimica Acta.”
https://www.sciencedaily.com/releases/2016/02/160222111420.htm