Exploring abrupt climate change induced by comets and asteroids during human history

Zolfagharifard and The Mail: A comet DID wipe out first North American prehistoric humans: Ice core data suggests a cosmic impact killed off Clovis people

Tusk Crush?

  • A comet DID wipe out first North American prehistoric humans: Ice core data suggests a cosmic impact killed off Clovis people
  • Evidence found in an ice core has been dated back to the ‘Big Freeze’
  • The freeze is linked to the demise of the North American Clovis people
  • The evidence suggests that a cosmic impact caused planet’s colder phase


Link to The Mail article

Comments still coming

A cosmic impact 12,900 years ago could have led to the demise of the ‘Clovis’ people of North America, researchers claim.

A layer of platinum from an ice core taken in Greenland has been dated back to the time of a known abrupt climate transition, known as the ‘Big Freeze’.

The freeze has been previously been linked to the demise of the Clovis people, the prehistoric hunter gatherers who were the first to occupy North America.

According to researchers at Harvard University, this provides evidence that a comet tipped the world into its colder phase, making dozens of species extinct.

A layer of platinum from an ice core taken from Greenland has been dated back to the time of a known abrupt climate transition. According to researchers, this provides evidence that a comet led to the demise of the Clovis people, the prehistoric hunter gatherers who were the first to occupy the North America

Researcher Michail Petaev and Harvard colleagues, writing in the journal Proceedings of the National Academy of Sciences, found a 100-fold increase in platinum concentration in ice that is around 12,890 years old.

This is the same period for which oxygen isotope measurements show rapid cooling of the climate- a period known as the ‘Younger Dryas’.

The Younger Dryas, or the ‘Big Freeze’, saw a rapid return to glacial conditions in the higher latitudes of the Northern Hemisphere between 12,900–11,500 years.

The Big Freeze is associated with the extinction of large mammals, such as the mammoth, and the demise of the North American Clovis people
Some scientists believe that the Clovis people chose to discard spears (pictured) and were not wiped out by a comet

Researchers claim that debris thrown into the atmosphere in an impact may have tipped the Earth into global cooling, wiping out native cultures such as the Clovis people.

As evidence for the rapid Clovis depopulation, comet theorists had previously pointed out that very few Clovis archaeological sites show evidence of human occupation after they died out.

At the few sites that do, Clovis and post-Clovis artifacts are separated by archaeologically sterile layers of sediments, indicating a time gap between the civilisations.

They believe that the sediment is a ‘dead zone’ in the human archaeological record in North America, beginning with the comet impact and lasting about 500 years.

But others argue that a lack of later human occupation at Clovis sites is no reason to assume a population collapse.

U.S. archaeologists Vance Holliday pointed out that short-term occupation Paleoindian sites—Clovis or post-Clovis—are the norm.

‘That’s because many Paleoindian sites are hunting kill sites, and it would be highly unlikely for kills to be made repeatedly in the exact same spot,’ he said.

‘So there is nothing surprising about a Clovis occupation with no other Paleoindian zone above it, and it is no reason to infer a disaster.’

Read more: http://www.dailymail.co.uk/sciencetech/article-2383733/A-comet-DID-wipe-North-American-prehistoric-humans-Ice-core-data-suggests-cosmic-impact-killed-Clovis-people.html#ixzz2b9KmdcZR
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21 Responses

  1. I just found this —


    “Any new and radical idea should not expect to be suddenly accepted by everyone and it wasn’t. In the years after 2007, multiple papers in high-profile journals by well-known scientists came out criticizing the conclusions of Firestone. Some said that they couldn’t find the spherules and other reported that there were other possible explanations for the presence spherules, nanodiamonds, plant ash and iridium. Today, there is still much disagreement in the scientific community about the what caused the YDB line, how much the climate changed, and what was the cause of the extinction of many species at this time. What is NOT of any debate is that there is a boundary line found all over the world in sediments of this age, that the age of this line is the same everywhere and that the last known appearance of many lineages of large animals is right below this line. These are the facts of the case, it is the interpretation of the facts that are debated.

    I said that some scientists initially reported in publications that they could not find the spherules reported by Firestone in 2007. That no longer seems to be the case as at least 8 independent researchers have now been able to identify similar spherules in the the YDB at some of the same locations that Firestone examined and at other locations that Firestone had never seen. Prior to this publication, I would still characterize the general palaeoclimate/geological community to be skeptical of the YDB impact hypothesis but this new PNAS paper should go a long way to causing some to reassess their thinking. The data appear quite compelling to me albeit I am not an expert in this area. However, even if Firestone and colleagues (there are 30 of them representing professional scientists around the world) aren’t exactly right about how this event occurred, it does seem that they have a valid hypothesis that must be taken seriously going forward. Clearly some significant event is recorded for us in these sediments and that event must have been extremely unusual. It isn’t as if no one thinks that nothing exception happened at this point in history. Another hypotheses to explain extinctions and this break in the geology is that there was a close supernova that hit the northern hemisphere centered on North America and fried most of the life there and caused massive wildfires. That theory is older than the YDB meteor theory but has not gained any favor because supporting evidence in additional research was found wanting.

    What we see here is science in action. Ideas (hypotheses) are proposed to explain some observations, other critique that idea. Over time more evidence is gathered and it will either continue to support the impact thesis or suggest that it has little merit.”

  2. Knowledge of the platinum spike paper is now spreading through the science community.


    New evidence that cosmic impact caused Younger Dryas extinctions
    16 hours ago by Marcia Malory


    Text from the link below —

    (Phys.org) —A period of rapid, intense cooling, known as the Younger Dryas, took place about 13,000 years ago. Scientists think this sudden change in climate caused the extinction of many large mammals, such as the mammoth, and was the reason for the disappearance of North America’s Clovis people. According to one hypothesis, a cosmic impact caused the climate to cool. Using data from the Greenland ice core, Michail Petaev and his colleagues at Harvard University have found what appears to be evidence of this impact. Their research appears in the Proceedings of the National Academy of Sciences.

    Measurements of oxygen isotopes in the Greenland ice core show that around 13,000 years ago an episode of rapid cooling, which lasted only about 1,000 years, occurred. During this time, many megafauna became extinct and evidence of the Clovis people, one of the earliest human societies to inhabit the Americas, disappeared from the archeological record.

    According to one hypothesis, a cometary airburst triggered massive wildfires, which caused the climate to cool. Many scientists have rejected this hypothesis, citing lack of sufficient evidence, in favor of others. The most widely accepted one says that during the deglaciation process, fresh water from the proglacial lake Agassiz discharged into the Arctic Ocean, altering ocean currents.

    However, Petaev’s team says that geomorphological and chronological data do not support this. They claim that evidence for another hypothesis, that the eruption of the Laacher See volcano caused a volcanic winter in the northern hemisphere, is also lacking.

    Now, the researchers claim to have uncovered evidence of a cosmic impact at the Younger Dryas boundary. When examining samples from Greenland Ice Sheet Project 2 (GISP2), they found that platinum concentration increased by about 100 times approximately 12,900 years ago.

    Platinum/iridium and platinum/aluminum ratios were very high, indicating that the platinum probably did not have a terrestrial source. While most volcanic rocks have high Pt/Ir ratios, their Pt/Al ratios are low. Mantle rocks have low levels of aluminum, but their Pt/Ir ratios are much lower than that measured in the ice core.

    On the other hand, Pt/Ir and Pt/Al ratios in magmatic iron meteorites are very high, suggesting that the platinum found in the ice core came from a meteor.

    Debris from a cosmic impact would have caused the climate to cool so quickly that species would have been unable to adapt, leading to their extinction. The Clovis people would not have been able to cope with the catastrophic changes to their environment.

    The research lends support to recent claims that a sedimentary layer containing iridium grains and glass-like carbon with nanodiamonds, found at many northern hemisphere sites around the Younger Dryas boundary, is evidence of a meteor impact.

    Petaev and his colleagues caution that future researchers must locate an impact site in order to confirm this hypothesis.

  3. Thanks, Tommy, we are working on it. What did you note different? The banner I bet, which is messed up until the morning.

    I am personally looking forward to the Wiki Tusk!


  4. Great link, Trent. I read it again and again, and would have posted — but it is a arguably a spawn of a biblically guided blog, and thus verboten — which is not my way.

    But thanks for tossing it in the mix.

  5. It is unbelievable that the forensic evidence on the impact has proven so ridiculously not believed.

    Blinders, blinders, blinders – and vicious attacks when those attacking KNEW their questioning was inferior and pathetic.

    Is science also to be swallowed up in the bling bling of modern show biz that only when a pretty face comes along and signs on that the world begins to accept it? If so, science is in the saddest state since before Galileo, or at least since the days of eugenics.

    Forensics don’t lie – unless the researchers cherry pick and exclude evidence they don’t like. WHAT in the YDB Team’s evidence was even REMOTELY seen to be inadequate by the Daulton Gang? — who we all have to think should never be allowed guns with actual bullets in them. Maybe they couldn’t be allowed spades and trowels, either – because they can’t shoot straight with them.

    So, The Daulton Gang is going down in flames.

    Actually, what we all know they are doing is flailing around trying to find SOME smidgen of weakness in the several recent papers – ANYTHING they can bite into without pulling out their dental plates.

    As before, we can be certain they will point to FIRESTONE 2007 and pretend that no research has been done since 2007, trying to beat what they think is a dead horse (but which actually came frightfully close to the right conclusion right off the bat).

    The most ridiculous part was not even the insect poop thing, when you come down to it. The saddest part was that they HAD to know they were sampling in a specifically bogus (and obvious) way – and thinking they could get away with it. Like the YDB Team couldn’t rebut the hell out of their sampling and protocol failures?

    What were they THINKING?

    And after they did that, what was Bos thinking, siding with them? Is he that sloppy a scientist that he didn’t even READ their papers? Or is he such a bad physicist/scientist that he didn’t understand what they wrote?

  6. Steve Garcia,

    The “Dalton Gang” did what climate scientists are doing.

    The difference between AGW and it critics compared to the YDB hypothosis and its “Dalton Gang” critics is that there is less scam money on the Dalton Gang side and more contrary hard science infavor of the YDB hypothosis.

    And note, anthropology has been far worse in terms of hoaxes and generational suppression of data than even climate science.

  7. Trent –

    The only two global warming skeptics who have had any effect are Anthony Watts (meteorologist) and Steve McIntyre (statistical auditor), both retired and who don’t take a dime from anyone, industry or not. The amount of money going into the global warming is 90% going to the “warmist” side. ONE guy on the skeptical side – Willie Soon of Harvard – accepted grant money made available from oil interests a long time ago, and that money was donated to the university (MIT), not to him directly. You should hear him yell and scream when those accusations are made. Compare that to the billions of dollars going to the non-skeptical side – including money from oil interests who play both sides of the game, just in case – but mostly government money, none of which has gone to skeptics.

    I believe it is “Daulton, not “Dalton.”

    I do not accuse the Daulton Gang of accepting any money, just that their science is sloppy science. The Wittke and Harvard papers both chewed them up and spit them out. Actually, so did Israde.

    I totally agree that anthropology/archaeology have done some nasty suppression of evidence. I would point anyone to the Valsequillo site and Calico site.

    I do not understand what you mean when you say data is suppressed in climate science. I know of some, but I don’t know if you are pointing at the same ones I know of.

  8. Trent, if I missed which side you were arguing about global warming, my apologies.

  9. Hi Trent; All

    I believe the event was global. It was a result of the impact of a cloud of countless fragments of a comet, where the earth passed. Similar to how meteor showers occur ………

    I in particular (as well as many others) is enough to walk in that direction, I believe in cosmogenic hypothesis. When I started (2009) the study of cosmogenic hypothesis for paleo ponds, where often megafalna are found, in northeastern Brazil, from impactites I collected onsite and studies by archaeologists and geologists (2004) it was possible infer the cosmogenic origin for field ponds to 12,900 years.

    It was not an exclusivity of the northern hemisphere.


  10. Daulton? Is the u silent?

    Evidence of a celestial strike and subsequent findings are all well and good, but I do agree with Steve. This proves that a celestial body collided with the earth. Change of climate? This is where things get a little more murky.

    To suggest that Clovis man were wiped out because it got cold is akin to suggesting that turkeys drown when left out in a rainstorm because they can’t stop looking up. As well documented in all studies I have ever seen, paleo to modern day, people that get cold tend to put more clothes on.

    If, a very big if, Clovis people were little more intelligent than the average animal, this might be plausible. They obviously were more intelligent being able to utilize stone implements of their own making. This would suggest that making extra clothes including the use of furs wouldn’t have been a far fetched hypothesis.

    Yes I used hypothesis sarcastically. I just went there.

    While possible, again, I agree with Steve. Scientific bling.

  11. Trent –

    In your AUG 7 comment last year, the pasted-in article, one line stands out to me:

    “Scientists think this sudden change in climate caused the extinction of many large mammals, such as the mammoth, and was the reason for the disappearance of North America’s Clovis people.

    To me, that about the CLovis people SHOULD do one of two things:

    1. Convince people that Clovis was a VICTIM, not the serial killers athrnopologists have made them out to be, or

    2. Make someone go out and prove that Clovis did NOT die out then.

    To me, the Clovis die out was both the most surprising thing to me and also obvious proof that they did not do the Overkill. ANY CULTURE that would and could kill and eat all that meat should have been the most prosperous culture in the history of humankind up to that time. If it was climate, then whatever happened SHOULD have been a piece of cake for the Clovis people, as Jeff says: All they’d have had to do in a climate change was to put on a few more furs. (This is besides the fact that the mammoths, too, had made it through the all of the Pleistocene ice ages…)

    And, Jeff, Clovis had the same sized brain we have, and the same opposed thumb. His main problem was his infrastructure, or lack thereof. He was smart enough to make Clovis points, the most beautiful and elegant points of any of the Paleo-Indians (many of which may have been effective, but they were butt ugly). Those points are NOT an obvious thing to make from chert and the other stone materials. Someone had to put some serious thought into those, and then had to gain some terrific skills to accomplish even ONE Clovis point. Making them was a multi-step process, and any craftsman of any recent century would have been proud to make them.

    In my mind, Clovis points are the CNC parts of their time – bordering on perfection.

  12. I am going to post this ion this ice core thread, since it deals with ice cores:

    This is a comment I made at WattsUpWithThat.com, re a post about the flawed thinking about ice cores and CO2 records. I make different points than the post’s author did, but I DO agree with where the post’s author was going.

    IMHO my criticism applies to O18 as well, in fact all “trapped” gases in ice core layers.

    My comment:

    Steve Garcia January 27, 2015 at 9:57 am
    My own take on this comes from my design experience with 16-position hot runner plastic multiple-layer co-injection blow-molding machines, working in R&D in dealing with laminar flows. (Note the term “hot runner”; this is FAR different from 90% of all plastics, which have COLD runners (or passages).)

    When fluid materials with whatever viscosity (from runny to thick ooze) flows “laminarly” within or on solid surfaces, the fluid does not all flow at the same rate. Laminar flow is slow enough so that their is no turbulence, so that the layers STAY in layers. Mixing layers in our case was a VERY undesirable condition.

    The fluid right up against the solid surface has friction WITH that surface, and that friction make the flow slower than for the fluid farthest from the surface. The fluid in contact with the wall and for a very short distance away from the all is called the “boundary layer”. In between the boundary layer and the farthest fluid layer there is a flow gradient. In multi-layer plastics, the velocities of these layers is critical to getting each and every layer to arrive inside the plastic molds at the proper time. (This is necessary because the plastic bakes while in the heated passages, changing its properties, which is not good at all. So it is imperative to have equal time for all the layers in the passages/runners.)

    So I have experience dealing with layers within laminar fluid flows.

    One thing to be aware of is that in laminar flow the layers do NOT all flow the same speed. For glaciers, this is all important. But it does not ever seem to be taken into account in ice cores.

    Ice in glaciers – according to the experts – also is a laminar flow. Those layers are all moving at different speeds, down the mountain valley. The top surface is traveling at one speed, and each layer down moves a little slower – or perhaps faster in some cases, because of the water at the basal ice (that I think doesn’t always exist).

    The ice does not flow monolithically.

    This is actually known, that the ice moves in layers that are in shear – sliding over each other.

    So, how does this affect ice cores? The mere existence of these shearing layers means that an ice core is NOT measuring the ice laid down at that point throughout the history of the drilled ice core. If the layers are going different speeds, then as we look down an ice core, we need to understand the time element in the different flow rates. But I have never seen this discussed – ever.

    Example: If the ice 10 meters down traveled slower/faster than the ice at the bottom of the FIRN, then the history shown in the ice core at -10 meters is from a different time than the ice that was under that drilling location 10 years earlier. That ice may have been 2 meters or 20 meters up or downhill 10 years earlier.

    So, the ice core is reading ice laid down at MANY locations, all of which just HAPPEN to be in that vertical column at the time the drilling is done. The layers SEEN just happen to line up that way because the drilling was done THEN. If done a year later, the ice layers will be all different.

    NOW, add in this:

    The shearing of the layers screws up the supposedly “trapped” gases, churning them all the time. ALL THE TIME. One layer sliding over the other one carries material from the bottom of one over the next layer down. What effect does this have on the gases? One thing is certain: It does not leave those gases unaffected.

    Now, add in this, too:

    No two glaciers move at the same speed, nor over identical ground. Therefore the shearing internally between the layers in one glacier will be different from other glaciers.

    All of this is terrifically complicating the simplistic idea of the ice cores as a record of the past atmospheric gases.

    The simplistic idea cannot be correct.

    Until they have a way of quantifying and empirically testing the variables – and then keep on verifying that those variables are known and included – the entire trapped gases principle cannot do what they say it does. They can’t even tell if the ice in a layer was laid down at the same location as the layers above it. LITERALLY, the ice in any layer may have come from 1 or 2 or 3 km away from the top ice. Perhaps more.

    Basically, the trapped gas in any layer is ASSUMED to be pristine and pure and unaffected by anything.

    In March, 2004, Polish Professor Zbigniew Jawaworski argued here (http://www.john-daly.com/zjiceco2.htm) before the US Senate that the very act of extracting ice cores releases many of the gases that are studied as if they ARE pristine and pure, but he says that this is wrong. Those gases go both into the drilling fluid and into the atmosphere, he says.

    WUWT is interested in the CO2. I am interested also in the O18, which is the gases we see when we see the Greenland GISP and GRIP ice core traces.

    I think MY complicating factors – which are not taken into account – would make the Greenland ice cores not show necessarily what they appear to show.

    IOW, those severe ups and downs in Greenland’s “climate history” may not really BE there in the Greenland ice history at all. Yes, as measured, there seem to be up to 14°C ups and downs – but did they actually HAPPEN?

    When the ice 13,000 years ago which shows up hundreds of meters below the GISP or GRIP or GRIP2 drilling sites may have come from elsewhere (not directly below) because the ice flows move each layer differently, they not only represent another location, but also the compressed gases have had to deal with shear between one layer and another. What effect did this shearing have? And if that layer is from somewhere ELSE, then how much can we trust that that layer is really THAT old? Or that the gases haven’t been churned with gases from other layers as the layers slid over one another?

    I do not know the answers to this. I only know that i have these concerns that to me create doubts. Doubts as to what has actually been measured.

    The Vostok ice cores show much milder and more gradual swings. Which is right? Or neither?

  13. Steve; Just one question. I can see the ice movement idea as being significant but does the Greenland ice sheet which is almost totally encircled by mountains really move much at all in comparison to Alpine Glaciers? I too had wondered about the contamination of gasses during the drilling process.

  14. Jim –

    You hit on one of my points. The coastal mountain slopes and their glaciers are NOT the same as the almost totally mountain-locked interior ice sheets.

    Most of the ice cores in Greenland are on glaciers (a REALLY wrong idea, since the internal shearing means that ice at depth may have begun MILES from the surface where the drilled hole begins).

    In fact, I’d bet big money that if they tried to drill down in the same hole 5 years later they would get completely different ice at nearly all levels.

    But the famous ice cores on Greenland – GISP, GISP2, and GRIP – are all at the summit. THOSE I would respect much more. But I STILL think there is some ice shearing inside, so that the results should be read with some extra uncertainty.

    Adding to that, I would argue that the 2-km altitude forces MOST weather systems into weird directions, veering off course, so that what weather happens on the roof of Greenland could NOT reflect normal weather in the N hemisphere. Only certain weather systems make it over the top of the ice sheet. And also, since I LIVE at 2 km, I can tell you that we only get the REMAINS of some weather systems. The coastal ranges divert most of them in some way or another. So, using the weather HERE is apples and oranges to the weather on the coasts. But vis-a-vis Greenland, they read those summit ice cores as if they represent the entire hemisphere – and beyond THAT, to representing the entire globe.

    This is, I think, INACCURATE in its basic assumptions.

    A general rule in engineering (and in many other things) is that “The devil is in the details.” Simple, un-complex ideas may sound good at first reading, but when the real inquiry starts, the complexities should start showing up quite soon. Thus, the simple formulas of Newton will, at some point, run into some complexities that were not foreseen – such as the velocities out on the fringes of galaxies that have caused people to come up with the idea of Dark Matter. I DO recall that ONE astronomer had gone in a different direction from Dark Matter and suggested that what was really needed was a change in the value of the Gravitational Constant. But I never heard another thing about that idea. His idea was that, “Supposing Newton didn’t quite get it right?” A brilliant idea, actually. Why should we assume that Newton, with few tools at his disposal, would have gotten right the first time around?

    My rule of thumb has become:

    If a hypothesis is simple and straightforward, it is probably wrong, or at best incomplete. And if it is incomplete, it may be monumentally incomplete.

    A corollary to that is:
    When attempting to solve a problem of any complexity, first look to find the most difficult problem within the larger one. That will add the first additional level of complexity – if not several. In other words, look for where it can be WRONG or can FAIL.

  15. One more thing on the ice cores…

    I do not say that the ice cores do not represent the world’s climate. But I do say that there are serious reasons to doubt that this can be true – now or in the distant past.

    We all hear how the Arctic is warming up so much. But in OUR neighborhoods, no such thing is happening. (Yes, we all think we have anecdotal stories about the weather, how it is different from when we were younger. But many of them are wrong to begin with. We didn’t pay attention to the ups and downs of local temperatures when we were 12 or 22, and all we have are very spotty memories of what was happening then.)

    If Greenland is warming up NOW, more than the rest of the world, then what basis do we have for thinking it warmed – or cooled – the same as the rest of the world at times in the past?

    And if the degree of change in Greenland exists now, compared to the rest of the world, how would we know that that degree of change would hold true in the past? Perhaps it was more. Perhaps it was less. And if so, by how much? And if it changed ratios since then, then when we see a temperature graph of then, how do we know how much to reduce temps to represent global temps then?

    Long story short: We don’t.

    So, then, in the GISP2 graph does a 9°C downward spike at the YDB mean a 9°C downward spike for the whole world? Or an 8°C change? Or 7°C? Or 3°C?

    Add to that the Vostok core which shows much less change. NOW what answer do we come up with? With only one or three or five data points available – and all of them in the arctic regions – what can we really extrapolate and understand of what happened at the YDB, climate-wise?

    Don’t expect a real answer, and when someone asserts a definitive answer, don’t believe that person – because he doesn’t know either, and is just blowing it out of his bum.

  16. Steve; I’ve read a couple of articles on Malaga Bay about ice core drilling and they all mentioned that there were times when they came back to a bore hole to redrill a site they found the ice under surface had indeed moved to a point where they had to drill a complete new hole to get to the bottom of the ice. There was also a picture of a drill camp that was located inside the ice on the Greenland ice cap. They had excavated into the ice and put a cover over the camp. Within 2yrs the camp had to be abandoned because the moving ice had crushed it beyond use. The same thing had been reported in Antarctica at drill sites. I’m willing to bet if coring was done at the outer edges of the Greenland ice cap one would find that the ice was indeed moving up the inward sides of the coastal mountain ranges.

  17. Jim – This link should show that your Drake Passage is not a unreasonable conjecture > http://phys.org/news/2015-01-amazing-impact-crater-triple-asteroid.html#nRlv

    This shows that not only are crater chains out there but that they can happen on low gravity planets.

    I say that last because SOMETHING has to break the object apart, and that something isn’t always the gravity of Jupiter. If these three objects hit so close together – in space AND time – then IMHO the fragmentation must have been in the later stages of its approach to Mars. Otherwise the fragments would have been stretched out in a string of pearls over some hours..

    Rough calculations:
    With fragments traveling at ~30 km/sec and Mars also traveling at 24 km/sec, those three impacts had to be VERY close together in time and close together in space, too. After all, this is hitting a bullet (the planet Mars) with not just ONE bullet but THREE (if it is truly three). And they all were able to hit within a few km of each other. In other words, they were likely almost still connected at the moment of impact.

    The scientists states,

    “The ejecta blanket appears to be uniform around the triple-crater showing no signs of burial or overlapping ejecta from overprinting craters,” write scientists Eric Pilles, Livio Tornabene, Ryan Hopkins, and Kayle Hansen on the HiRISE website. “The crater rims are significantly stunted where the craters overlap.”
    This oblong-shaped crater could have been created from a triple asteroid, or it could have been a binary asteroid, and one broke apart, creating the three overlapping craters. The team says the two larger craters must have been produced by asteroids of approximately the same size, probably on the order of a few hundred meters across.
    “The northern crater might have been created by a smaller asteroid, which was orbiting the larger binary pair, or when one of the binary asteroids broke up upon entering the atmosphere,” the team explained. “The shape of the triple-crater is oblong, suggesting an oblique impact; therefore, another alternative would be that the asteroid split upon impact and ricocheted across the surface, creating additional craters.”

    Read more at: http://phys.org/news/2015-01-amazing-impact-crater-triple-asteroid.html#jCp

    Alternatively, like comet Itokawa, the impact pattern may have been created by a single peanut-shaped object – not likely, but with Mars’ thin atmosphere perhaps not impossible. That idea is perhaps as likely as the idea that it was from three fragments hitting so close together.

    If it WAS 3, then Elysium Planitia is only 3°N of Mars’ equator, so its rotational velocity is very close to Mars’ equatorial rotational velocity of 433.3 km/Earth hour (or 0.12 km/sec) – about the speed of the latest mag-lev high-speed trains. Add that to the velocity through space. So for every 8 seconds the first impact location would have moved 1 km “eastward”, just on the rotation. The 24 km/sec through space is the biggie. If it was a broadside impact those three impacts wouldn’t be likely to be made by three separate objects. But that is precisely why if it WAS three, they must have been VERY close to each other.

    THAT implies a very late breakup – likely within the atmosphere of Mars, as thin as that atmosphere is. From http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html we find that the atmosphere is “Surface pressure: 6.36 mb at mean radius (variable from 4.0 to 8.7 mb depending on season) /// [6.9 mb to 9 mb (Viking 1 Lander site)]” Earth’s surface pressure from the Earth fact Sheet is 1014 mb.

    The 6.36 mb at Mars “sea level” is equivalent to 35.5 km altitude on Earth. According to at least one paper, Borovicka et al 2013*, the Chelyabinsk meteor entered Earth’s atmosphere at 95 km and exploded at 17.2 km. These easily bracket the 35.5 km Earth altitude equal to Mars’ surface pressure. Chelyabinsk’s airburst at 17.2 km would seem to make it seem quite possible that the Mars meteor could have airburst just before surface impact.

    Could a similar atmospheric break-up also have happened then at the Drake Passage? While the above doesn’t cover all the bases, it seems worth further consideration.


  18. Steve; I had earlier calculated that the Drake Passage impact probably came in at a 35-45 degree angle. Now if this is a fragment of a much larger object and the object broke up higher in the atmosphere and at least 3 other main breaks occurred, Would the initial velocity of the main object slow down as it traveled in it’s declining orbit or would it maintain speed or speed up as it shed mass. I believe the calculated impact speed at drake Passage was approx. 75,000mph. What I’m trying figure here is the timing of the impacts. the impacts occurred coming from west to east. Do I subtract the earths speed from the 75,000 or add it to the 75,000? I believe I can get the distances between the strikes from the GPS site so this may not be as difficult as I thought. I have a tendency to overthink problems.

  19. Jim –

    As to the speed ay atmospheric entry and past, the Borovicka et al 2013 paper entitled “The trajectory, structure and origin of the Chelyabinsk asteroidal impactor” has a chart of the velocity of that meteor through its atmospheric flight. The mechanics of that flight should be somewhat representative of in-atmospgere flights, regarding slow-down. That chart showed the velocity as such:
    T*(s)-Lg*(°)-La(°)*-Ht*(km) V*(km/s)
    1.07 64.477 54.454 95.0 19.03
    6.97 62.888 54.664 60.0 19.05
    10.46 61.933 54.780 40.0 19.03
    12.24 61.442 54.837 30.0 18.9
    13.18 61.193 54.864 25.0 18.0
    14.18 60.943 54.892 20.0 14.2
    15.17 60.802 54.907 17.2 6


    This is the caption to the chart, for our education:
    Time zero corresponds to approximately 3:20:20 UT. Coordinates are given in the WGS84 geoid system. Speed is relative to the Earth’s surface. At the beginning, the acceleration due to gravity was larger than deceleration due to atmospheric drag. The beginning speed (19.03+/-0.13 km/s) remained constant to within 0.02 km/s down to an altitude of 35 km. The bolide was recorded in the analysed videos between altitudes of 95.1 and 12.6 km, over a trajectory of total length 272 km. The apparent radiant was changing owing to Earth’s gravity…

    75,000mph = about 21 km/sec. That may or may not be high, depending on the direction of approach.

    Do you subtract or add? THAT totally depends on the direction of approach. If it comes from behind the Earth (in the same direction but overtaking), then you subtract. And if they are more head on, you add. The Earth is going about 30 km/s, so with cometary velocities up to 70 km/s, they can overtake.

    That velocity thing is one MORE reason I shake my head at the 19.05 km/s entry velocity for an Apollo object coming almost directly from behind. As I understand it, asteroids don’t go the necessary ~49 km/sec to overtake with that kind of relative speed on atmospheric impact. (But that is just me…)

    Jim – Just so you know, I think a Drake passage impact is totally possible, but I don’t actually think you’ve got anything on the other impacts being connected. BU-U-U-U-UT – I also think it is worth looking into. So, keep at it, and let’s see where you go…


  20. a second new mexico clovis kill site has been identified.

    “Much of what is known about the Clovis people comes from an archeological site near the town of Clovis in eastern New Mexico. At the Blackwater Draw, the Clovis people killed and butchered several mammoths, leaving evidence of their existence, their hunting skills and their beautiful spear tips in one place.

    This would be the second time Clovis artifacts have been found in conjunction with a mammoth.

    This is the kind of find that intrigues funding entities and Huckell, along with two UNM professors from the Earth and Planetary Sciences Department, Leslie McFadden and Grant Meyer received a National Science Foundation High Risk Research Proposal to excavate the mammoth.

    It’s a wonder the mammoth, which they think is a juvenile, was preserved at all because it fell in a place that was vulnerable to the elements, on a little shelf of land between two deep arroyos.

    “The bones were buried in a very small stream channel, not much bigger than a person could jump across,” Meyer said. “Even more unusual is the channel location: it is perched on the side of a steep canyon. Landslides occurred here sometime during the last episode of Pleistocene ice ages, when mountain glaciers grew in the high Sangre de Cristo Mountains and the climate was colder and wetter in New Mexico.”


    I wonder what the exact dating will be of the find?
    Will it fall into the YDB window, and is there the trace evidence of the enet that there is at Blackwater draw.
    What is a shame that people aren’t looking for the trace evidence of the YD impact event at sites like this.

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