Kerr Watch

Elapsed time since Richard Kerr failed to inform his Science readers of the confirmation of nanodiamonds at the YDB: 6 years, 3 months, and 7 days

Separated at Birth? Worldwide Dragon Myths and Meteor T(r)ails

 

 

What’s up?

From Hermann Burchard:

George,

here is  a simple model to explain the vapor trail’s observed symmetry:

Partial cloudlets each side, North & South,

have almost identical ones opposite.

 

1.  The Bos’ blowtorch momentum sims and video blow-ups from Steve Garcia’s

posts indicate that the explosive ablations shoot debris ahead in the

direction of motion, both vapors and frags.

2.  The vapors immmediately begin to rise initially as whole cloudlets.

3.  By the time the main body of the meteoroid catches up with a cloudlet,

this will have risen a bit, so its bottom is hit off-center.

4.  The meteoroid pierces the cloudlet at its bottom leaving clear air

behind, creating the impression that there are two parts.

5,  Indeed, there appears to be a top part connecting North and South.

 

  • Steve Garcia

    Okay, I am in a bitchy mood today, guys.

    That Science Daily article starts out,

    “A new look at conditions after a Manhattan-sized asteroid slammed into a region of Mexico in the dinosaur days …”

    What does “Manhattan-sized” mean? Egocentricity? Diameter equal to the length of Manhattan? The width? The mass? If mass, how much depth do they include? Does it include the buildings?

    Or are they just pandering to the NYC market? (Naw, that couldn’t happen. No one has ever done that!)

    /snarc

  • Steve Garcia

    Sorry, but one more here:

    New Evidence Ancient Asteroid Caused Global Firestorm On Earth Mar. 27, 2013

    A new look at conditions after a Manhattan-sized asteroid slammed into a region of Mexico in the dinosaur days indicates the event could have triggered a global firestorm that would have burned every twig, bush and tree on Earth and led to the extinction of 80 percent of all Earth’s species, says a new University of Colorado Boulder study.

    Led by Douglas Robertson of the Cooperative Institute for Research in Environmental Sciences, or CIRES, the team used models that show the collision would have vaporized huge amounts of rock that were then blown high above Earth’s atmosphere.

    IT’S A MODEL. It is not real. It is based on THEIR assumptions, which could throw the results off by magnitudes and magnitudes – and even give it the wrong sign. (Trust me – it has happened…)

    There is no more evidence in a model than in a Bugs Bunny cartoon.

    UNLESS…

    Unless it is in a scientific area that has been well-verified by real-world experience and ALL equations – and limitations – are known. For example, a model of a building you can trust, because all the factors have been worked out long ago.

    But scientific areas in which variables have to be guessed at – no one should even SLIGHTLY accept the results. Every guess has huge uncertainties in its input values – many times much larger than the guess itself. As to PROCESSES, Katy Bar The Door, because each researcher has his idea of what the processes were/are.

    Seriously, un-aligned observers are only just now waking up to the fact that the dozens of climate models that the UN IPCC bases its forecasts on to the year 2100 – NONE of those models is worth a dime, in terms of how it replicates nature. I won’t go into the known fudges the modelers input, but some of them are single-value guesses representing very complex processes. In fact, the processes are so complex no one can model the individual processes, much less incorporate the processes into the bigger GCM models.

    In other words, if you can’t verify a model’s outputs/results, in order to TEST the model, then don’t trust the model. It is, after all, just a program, one that can have wrong inputs, wrong formulae, and wrong coding.

    They DO make pretty pictures, though. Mostly, anyway.

  • Hermann Burchard

    [Steve Garcia March 23, 2013 at 6:29 pm:]

    Trent – I am SO doubtful about the 500kt number you can’t believe. If it DOES happen to be true, it was all released along its trail, from radiant point to final disintegration (that most people call its air burst), which, by itself had the immensely, gigundous, tremendous power to (WOW!) blow out windows and knock down a building that was likely going to collapse in the next two snow seasons. A 500kt nuke at that height would have offed thousands of Chelyabinskians.

    True! But just imagine tilting that long vapor trail to a steeper angle, the exploding double tubular structure incoming at a 20 degree angle, and make it nearly vertical, the blow torch forward momentum flame thrower likely would have been in effect to wipe out a city, except it would have been Korkino or Roza across the pit mine.

    [Am off-Tusk on rush projects for a while.]

  • Steve Garcia

    I might be wrong, but it seems they gauged the 500kt solely on its mass and didn’t consider the low inclination and the energy losses.

    I agree, Hermann, that a steeper slope would have been a different story. But its not like they predicted the 500kt before the fact. They all came up with that number after the fact.

    If THAT puny bang was 500kt, what were we so worried about during the Cold War?

    BTW, I haven’t been able to find out the infrasound data used to make determinations about its kt.

    Anybody?

  • From Space Daily regarding the dinosaur extinction event 66M/65M ybp
    “CU study provides new evidence ancient asteroid caused global firestorm on Earth”

    http://www.spacedaily.com/reports/CU_study_provides_new_evidence_ancient_asteroid_caused_global_firestorm_on_Earth_999.html

    Interesting quotes regarding ejecta morphology and heat transport. In the case of Carolina Bays, if a shallow angle impact did take place at the Saginaw trench, the sandstone launched during cratering of that trench is Michael Davias’ proposed source for the sand of the CBays. That shallow angle strike idea does give good causality for lots of terrestrial melt drops being formed (and purified) in “astronomic” volumes during such crater ejecta process, especially if you look at the layer of sandstone that is part of the missing strata of the Saginaw trench. What Mr. Davias is at a loss to explain so far is the particular shape of the bays and their remarkable uniform regional orientation across wide ranging temperate latitudes of vastly varying weather, which is a detractor of the wind/water formative process proposed by Geologists in the Uniformitarian camp of that science I.M.H.O.

    But back to dinosaur extinction…

    “The conditions leading to the global firestorm were set up by the vaporization of rock following the impact, which condensed into sand-grain-sized spheres as they rose above the atmosphere. As the ejected material re-entered Earth’s atmosphere, it dumped enough heat in the upper atmosphere to trigger an infrared “heat pulse” so hot it caused the sky to glow red for several hours, even though part of the radiation was blocked from Earth by the falling material, he said.”

    “But there was enough infrared radiation from the upper atmosphere that reached Earth’s surface to create searing conditions that likely ignited tinder, including dead leaves and pine needles. If a person was on Earth back then, it would have been like sitting in a broiler oven for two or three hours, said Robertson.

    The amount of energy created by the infrared radiation the day of the asteroid-Earth collision is mind-boggling, said Robertson. “It’s likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth.”

    It really does sound eerily like fire and brimstone, as if Humanity really has witnessed such horror at some time(s) in the orally recorded past.

    Also for a violent enough shallow angle strike to excavate the saginaw trench from under the mile or two mile thick Laurentide Ice Sheet would have required an impactor typically larger than that ice thickness dimension. Mr. Davias has isolated the likely epoch of formation of the CBays as between 100k and 200k years before present, so can not directly be the Younger Dryas Lower Boundary impact suspect. All of these impactor issues, however, are related for that very reason.

    Steve G.

    That 500 kTons was spread out over a large horizontal distance and, more importantly I believe, released at substantial altitude. Realize that the energy was delivered into extremely thin atmosphere where the impedance is relatively low to things like passing hypersonic objects, shock waves, spreading fireballs, and convection. Now this is a relative term but I’m talking about far less impedance than anything anywhere near the surface where the atmosphere is exponentially more dense and therefore higher impedance. So on a relative basis….

    Low impedance.

    The shock in the Chelyabinsk case apparently traveled for nearly 1.5 minutes before first detection on the ground near directly underneath (point of first ground contact by shock wave). This is a substantial time to allow for geometric dissipation of shock front intensity. This time delay alone, combined with the tenuous nature of the high altitude medium of delivery, mean that the folks of Chelyabinsk were exceptionally lucky that day.

    Exceptionally lucky. High fry-ability of the component that fire-balled is also responsible for the high altitude cook-off, as is likely the shallow angle approach as well.

    The infrasound detection technique uses long wave acoustic energy waves to estimate energy at the source assuming some known distance. Infrasound is just sonic instead of RF spectrum, very low low low in the sonic range. A sensor array at the detection station gives a direction, which they compare to other stations. Then the triangulated distance estimate is used to estimate the yield or energy released by the event. It does rely on mechanical models to use in the computation, but the models are well correlated to known events. Because as we know, if the model is garbage so are the results. Likewise even with a good model (well calibrated or correlated), garbage in will still give garbage out. My degree is basically in modeling of mechanical systems, so I’m very familiar with the garbage model concept. Pitfall of endless manpower and resource. Always beware the model. And as a practicing dynamicst on a developmental flight test program for the V-22 Tiltrotor, I was always one to trust measured values above all others, be those others calculated, implied, inferred by management or specification, or whatever their source. Measure and compare. 7th grade shop. 4th grade science.

    The distance is estimated by triangulation from a number of detectors. In the Chelyabinsk case many stations detected the event, w/ the nearest detection station apparently Alaska, some 6k miles from the event. At this great range, the dispersion of various wave lengths within a wave packet from an impulsive event (weather is be a focused explosion or one released briefly over a distance as in our hypersonic Chelyabinsk case) will tend to make the energy values similar in either case. What is different is the actual shape of the wave (more properly the “wave train”), which probably explain the scatter in the actual triangulation estimations shown in some of the graphics presented after detection of that event. I have an idea of this because I’m a dynamicist by training and by profession, and I’ve studied these type systems both in school and in many different cases at work on both Spacecraft and Aircraft. (FYI S.G.)

  • Hermann Burchard

    And further, due to the low atmospheric pressure ~~ .0001 to .01 Atm along the luminous trail’s varying altitude of 300,000 feet down to 80,000 feet at the point of maximum energy output and radiative brightness, effects are almost as if it exploded in vacuum outside air ocean, half lost to space as EM radiation, much of it in the IR spectrum.

    Most of the energy of 440 kilotons, according to Wikipedia (revised), was absorbed by the air, as seems plausible (more correctly, half lost to space).

    And, at the distance of more than 15 miles, would not a 440 kiloton explosion at a height of 2500 feet (or so) have been survivable by people on the ground?

    BTW, as I just verified on my calculator, the 440 kilotons or .44 Megaton TNT estimated energy equate to

    .44 Mt = 1.8×10^9 kilojoules,

    and this is the exact kinetic energy of the space rock, 11,000 tons moving at 18 km/s.

    For the definition of Mt unit = 1 Megaton of TNT, see here:

    http://www.unc.edu/~rowlett/units/

    Not stated there, apparently the nuke physicists (sneaky guys) have defined
    somewhat arbitrarily

    1 Mt of TNT = 10^12 Cal,

    where 1 Cal is the “large” or kilo calorie used by dieters.

    In other units:

    1 Mt of TNT = 1.00 x 10^12 Cal
    = 4.18 x 10^12 kilojoules
    = 1.16 x 10^9 kwh
    = 3.97 10^12 Btu

    [Better check these figures for yourself, as this is a sleepy mathematical philosopher.]

  • I’m guessing the CU folks used the proposed energy delivered by the bolide divided by the area of Earth and got that megaton per square mile number.

    Infrasound detection of Chelyabinsk event, shows data in the form of strip chart traces

    http://www.space.com/19860-russia-meteor-explosion-largest-detected.html

  • Oops Space dot com has more goodies on Chelyabinsk, published early after the event?

    http://www.space.com/19829-russian-fireball-meteor-blast-infographic.html

  • Steve Garcia

    TH –

    Yes, I saw those strip chart traces. Amazing that anyone uses those anymore. 1940s technology updated to the 2010’s? Just for public consumption?

    The 2nd link is a real pap for the masses PR department effort to put out some eye candy and look like they are on top of things.

    They certainly do NOT have the final path aligned correctly.

    I may not know all the technical things, but I DO want to know it, and you can see I am not afraid of asking questions that might show my lack of knowledge. But I also don’t want to be insulted.

    When will any science institution realize that not everyone is a 4th grader? It would be awfully nice to see them produce something with some beef in it. You can almost see them patting us all on the head and saying, “Run along Sonny, nothing to see here.”

    Three more levels would be nice – one for high school grads, one for general college folks/grads, and one for people in the sciences and engineering. Them talking down to EVERYONE and assuming no one can understand any of it above “See Moon; See Moon orbit” level is pathetic.

  • Trent Telenko

    >“[S]cientists from NASA’s Lunar Science Institute (NLSI) in Moffett Field, Calif.,
    >discovered that the same population of high-speed projectiles that impacted our
    >lunar neighbor four billion years ago, also hit the giant asteroid Vesta and
    >perhaps other large asteroids.”
    >
    >You’ve GOT to be kidding.
    >
    >Some agency actually paid (non-Monopoly) MONEY for this study?
    >
    >I don’t even know how to express the ridiculousness of studying something that is
    >so patently obvious. What did they think impacted the Moon? Bubbles from Mars?

    Steve,

    Confirming the blindingly obvious with hard data is also part of the scientific method…plus it lets them get paid to eat regular and sleep indoors.

  • Trent Telenko

    >What the hell does THAT mean?! Every four miles vertically? E-W? N-S? E-W AND N-S?
    >Every 4 SQUARE miles?
    >
    >Talk about geeks that can’t communicate, WOW. If it is the journalist, the dude
    >aught to get a job flipping burgers. He’s almost as bad at that as Bos is at air
    >bursts (as opposed to ‘Marlboro Man’ posing).

    This was likely the Science Daily editorial staff butchering the press release hand out.

    My wife did technical writing in a former job and twits the S.D. writers work to me regularly.

  • Actually, the late lunar heavy bombardment has been an outstanding mystery and controversy for some time, and insight into this phenomenon was gained through the giant gas planet migration by looking at both extrasolar systems and the scattered disk of trans-Neptunians and Kuiper belt objects, in addition to simulations which are able to reproduce some aspects of the asteroid belt. By looking at the cratering and dark thin organic layer at the surface of Vesta, a large and relatively pristine object in the asteroid belt, some confirmation of the models were thus obtained. There were a lot of other competing hypotheses that didn’t pan out at the end of this.

  • Trent Telenko

    >IT’S A MODEL. It is not real. It is based on THEIR assumptions, which could throw
    >the results off by magnitudes and magnitudes – and even give it the wrong sign.
    >(Trust me – it has happened…)
    >
    >There is no more evidence in a model than in a Bugs Bunny cartoon.

    Why are you surprised by this.

    Any successful scam — UN Climate change modeling for instance — breed’s imitators.

  • Trent Telenko

    Thomas Harris said —

    >Infrasound is just sonic instead of RF spectrum, very low low low in the sonic
    >range. A sensor array at the detection station gives a direction, which they
    >compare to other stations. Then the triangulated distance estimate is used to
    >estimate the yield or energy released by the event. It does rely on mechanical
    >models to use in the computation, but the models are well correlated to known
    >events. Because as we know, if the model is garbage so are the results. Likewise
    >even with a good model (well calibrated or correlated), garbage in will still give
    >garbage out.

    This gets us back to the point that atmospheric disturbance infrasound models of nuclear detonations are “well correlated to known events.”

    The atmospheric disturbance(s) from a “High fry-ability object” breakibng up upon impact in on our atmopshere are not “well correlated to known events.”

    You need 20 of anything to even begin a statistical analysis.

    How many 100 KT plus energy release atmospheric impacts of extraterrestrial objects have these infrasound detectors measured?

  • Models and the computers that run them are ‘analytical tools’. You guys need to try and wrap your minds around the concept of ‘multiple lines of evidence’ and ’empirical observations’ and well as ‘mathematical theory’ and ‘unviable hypotheses’. You may now return to your wild speculations and conspiracy theories.

  • Barry Weathersby
  • Steve Garcia

    Trent –

    I had posted this:
    “[S]cientists from NASA’s Lunar Science Institute (NLSI) in Moffett Field, Calif.,
    >discovered that the same population of high-speed projectiles that impacted our
    >lunar neighbor four billion years ago, also hit the giant asteroid Vesta and
    >perhaps other large asteroids.”

    Actually, the real deal with that is this:

    If the both the asteroid belt and the Moon were pelted by that population of projectiles, then so was the Earth.

    Duh.

    Oh, excuse me, GOD protects the Earth. God and the Uniformitarians who say (…altogether now, class…) “It can’t happen here!”

  • Steve Garcia

    TH –

    Models are not viable “lines of evidence.” Models are not evidence. Models are not empirical. Models are guesses, guesses with pretty pictures. Models are not real.

    I say all that in re research. Models for engineering are SOLID and are replicatable – and ARE.

    Models for research are – in this area especially – figments of the imagination. And don’t say they are based on “the best information possible,” because the history of science is rife with the skeletons of “reasonable” guesses that empircally were proven wrong. Reasonable is not science. Reasonable is still guesses.

    These are the best minds, so their reasonable guesses are more than just reasonable guesses? Watch Richard Feynman’s lecture on the scientific method on YouTube.

    No. Until backed up by empirical evidence, models are only guesses. Guesses accompanied by cartoons.

    Ask ANY climate modeler to reproduce the last 40 years, even the last 20 years. In fact, ask ALL of them to do so. If you ask 15 of them, you will get AT LEAST 15 different hindcasts – and NONE of them will agree with actual climate records.

    All of those models are based on “reasonable” assumptions – and all of them fail Feynman’s test of “comparing to experience.”

    So don’t be bringing models in here and claiming they are “lines of EVIDENCE.” They are lines of assumptions.

    In fact, an argument can be made that models themsleves are “unviable hypotheses” and “speculations and conspiracy theories.”

    Sorry if that steps on your modeler’s toes, but models can only reflect (at best) the assumptions that go into them. And HOW does that make them anything more than guesses?

    I side with Robert Hooke, who insisted (but lost) the argument with Newton that only empirical evidence should be allowed in the Royal Society confabs. Models are not empirical, no matter how much you may think so.

    On of the big problems with the global warming thing is that modelers have come to confuse their models with reality – and take an entire science and almost took the world’s policymakers with them, down a Yellow Brick Road of imaginary science.

    Guesses are the first step toward scientific understanding. But without the REAL lines of evidence – experience and experiment – they are no better than what reasonable guesses come out of our heads. And in areas where experiments cannot be done, models need to be considered VERY carefully, because, like in global warming, they can lead people down imaginary alarmist blind alleys.

    And considering that impact is ALSO an alarmist direction, we HERE need to be especially wary of what we can “prove” with models.

    Look at Boslough, for example… Then compare to Chebarkul. Where was the downward blast? Somewhere he got his model wrong. Pretty cartoons, though.

  • Steve Garcia

    Maybe we can consider models to be Beta versions of reality – mostly correct, but you never know when the results will be something not necessarily correct.

    Again, I give you climate models. There are a LOT of people who actually believe models that can’t hindcast worth a damn or predict climate for the next year or five or ten are capable of telling us – within 0.1°C – what the climate will be in the year 2100.

    One can forgive the people like policymakers who depend on scientists to advise them on such things. After all, what do they know?

    But the scientists themselves – the climate modelers in particular – how can they look themselves in the mirror, knowing they are bullshi**ing the world?

    TH – I DO believe that SOME DAY models of such complex things as impacts and climate will be understood enough that the models will give reliable results. You and I both know that in those areas that day is not today. Too many unknowns. To many assumptions. Too many uncertainties.

    Chebarkul should increase our knowns. That is a good thing, and it should make our models better – but only if the knowns are really knowns. Again, I bring up the Columbians’ impossible Apollo asteroid orbit. If that is allowed to stand, models will have an error included in them. And nobody is even aware there is a problem.

    I am still communicating with the two guys working over at Tallbloke’s page about that. They are getting closer and closer – using a model – to showing that there is SOME reason to think that DA14 and the Russian object were part of a shower of sorts. Using the models they have – which I take with a grain of sand – they show this – and it goes more or less 90° from what the Columbians show. But they at least tie the radiant point and heading to the orbit they propose. There is nothing in the available non-paywalled literature about the Columbian’s orbit that shows how the orbit and the radiant and heading are connected.

    Are the two correct? Not yet. But I think there is enough known about orbits that a model is worth looking at. In THAT regard, this is a model based on much known material, basically at an engineering level.

    And if two models disagree? Obviously one of them would be wrong. It is almost certainly the tow over at Tallbloke’s who are wrong. But so far their model can put the object on the right heading at the radiant. At the same time, I freely admit that it is HIGHLY likely that I am overlooking something, and that the Columbians are correct. But dammit if I can tell what it is.

    hahah – the model in my head says the Columbians are wrong, and the other model (at Tallbloke’s) not only agrees with me, but it places the object exactly where I think it should be. Of all the places where their model could have said the object came from, it is remarkable that they put it there. So, am I agreeing with them just because their model agrees with me? Nope. But I think it opens up the possibility that I my brain model is right. And they are using a known, well-proven model as far as I know.

    So, do I only agree with models when they agree with my conclusions? No. I agree with engineering models – which includes NASA orbital models, which have been proven out in the real world. The farther from the real engineering world a model is, I simply think the more we should be wary of its output. In those cases, they are reasonable guesses, but reasonable guesses have enough of a history of being wrong that we should use them with caution.

    TH – You have never done a model that used assumptions that proved to be wrong? You never had to tweak your models, based on results not agreeing with experience or experiment? You always had it dead nuts? If so, I would posit that everything you worked on was at an engineering level.

  • I would like to ask a question. Approximately when was the mexico impact supposed to have happened? I’m new to this concept of impacts and it’s intrigueing.

  • Trent Telenko

    Steve G said —

    >If the both the asteroid belt and the Moon were pelted by that population of projectiles, then
    >so was the Earth.
    >
    >Duh.
    >
    >Oh, excuse me, GOD protects the Earth. God and the Uniformitarians who say (…altogether now,
    >class…) “It can’t happen here!”

    It is more like God erases the evidence of craters — air and water don’t form long lived craters and they both keep the ones on land from lasting through geologic time — while delusion and tenure protects the Uniformitarians from reality…and lets them persecute those who say “The Emperor has no cloths” out of academia.

  • Hermann Burchard

    Jim Coyle:
    Delighted to get you started — 65 million years ago, end-Cretacious.
    And so was Mumbai-Seychelles, a much larger event, 500 km crater
    off Mumbai. See under “Shiva” in Wikipedia. The Uniformitarians do
    not want to hear about it, so they label it “controversial.”

  • Thanks, Herman. A bloger, Big Al, Mnetioned seeing bay type structure while on a flight from Minneapolis to Denver. He thought they were over western Nebraska. These bays were aligned SE- NW not the alignment for a Saginaw impact bay. I first thought possibbly it might be from a Yellowstone volcanic blast but I don’t think vulcanism would produce that sort of impressions. The age you give is most likely too old for that to be the causation. So back to the drawing board. Have to keep looking Seatle to the Gulf coast. SDomeone must have lost an asteroid somewhere in that area. Jim

  • Hermann Burchard

    Jim Coyle,

    maybe you meant more recent event, 12.9 K BP at Lake Cuitzeo in central Mexico (20N,101W), YDR impact related. Details in article by Israde-Alcántara et al:

    http://www.pnas.org/cgi/doi/10.1073/pnas.1110614109

    Also, ashfall dated to 10 M BP, in NE Nebraska killed rhinos, “Ashfall Fossil Beds,” Wikipedia. Caused by explosion of Yellowstone hotspot in SW Idaho at Bruneau-Yarbidge caldera. The hotspot from 16 M BP impact, Modoc Plateau, NE California, “Chalk Mountain,” see 40.994,-121.809 on Google terrain map for central uplift. Also origin of Columbia River Basalt Plateau, LIP, Large Igneous Province. But pro geologists do not recognize impact volcanism, responsible for the numerous LIPs. For this, need impact through thin oceanic crust penetrate into mantle. Modoc Plateau was coastal.

  • E.P. Grondine

    “BTW, I haven’t been able to find out the infrasound data used to make determinations about its kt.”

    “Anybody?…”

    No s**t, Sherlock.

    BTW, the number is 540 KT, at ca. 22 kilometers altitude. More precise numbers will be publihsed in the future.

    Next, a quick comment about all the BS here about uniformatarianism versus catastrophism. That is not the problem. It is impact hazard estimates, and specifically those regarding cometary impact.

    Finally, a note about climate models and responding to any AGW hazard. If you look at the per capita CO2 numbers, if China and India industrialize the same way the US has and put out the same per capita CO2, we’re baked.

    But there are places to discuss those models adn workable responses. That being the case, the Tusk should not duplicate them, IMO.

  • E.P. Grondine

    Hi TH

    “How does one expect a complete plasma spawned by an irregularly shaped and disintegrating meteor to retain a directional momentum into a denser gas or solid over tens of kilometers, when minus those intense magnetic and gravitational forces, it can expand elsewhere?”

    Yeah.

    B.’s model also ignores what is known about the Tunguska meteoroid and its entry path.
    For that matter, B. is trying to with away the Chelyabinsk point explosion.

    While his interest in this field is laudable, it is clear to me that B. is trying to play way out of his league.

    In asm uch as typing away on the internet daily whould not be confused with meningful work, I hope you will forgive me, but I have some things that needed to be done yesterday.

  • Mr Burchard; I did some checking into the Lake Cuitzeo impact and it just might be the cause for the Bay structures in Western Nebraaska. I wasn’t able to locate any info on the entry trajectory of the object. If the entry was from a generally E-W or vice versa the butterfly ejecta pattern would fit and the time frame seems right. Thanks for your time in answering my ?s Jim C

  • Trent Telenko

    See–

    Glenn Reynold’s latest on asteroid defense and the lack of same from NASA.

    http://www.usatoday.com/story/opinion/2013/04/08/killer-asteroids-nasa-column/2061419/

  • Trent Telenko

    E.P. Grondine and Steve Garcia are going to have some real fun with this Science Daily article and the “SCEIENCE” article it is trying to quote —

    http://www.sciencedaily.com/releases/2013/04/130425144654.htm

    NASA Probe Observes Meteors Colliding With Saturn’s Rings

    Apr. 25, 2013 — NASA’s Cassini spacecraft has provided the first direct evidence of small meteoroids breaking into streams of rubble and crashing into Saturn’s rings

    These observations make Saturn’s rings the only location besides Earth, the moon and Jupiter where scientists and amateur astronomers have been able to observe impacts as they occur. Studying the impact rate of meteoroids from outside the Saturnian system helps scientists understand how different planet systems in our solar system formed.

    The solar system is full of small, speeding objects. These objects frequently pummel planetary bodies. The meteoroids at Saturn are estimated to range from about one-half inch to several yards (1 centimeter to several meters) in size. It took scientists years to distinguish tracks left by nine meteoroids in 2005, 2009 and 2012.

    Details of the observations appear in a paper in the Thursday, April 25 edition of Science.

    Results from Cassini have already shown Saturn’s rings act as very effective detectors of many kinds of surrounding phenomena, including the interior structure of the planet and the orbits of its moons. For example, a subtle but extensive corrugation that ripples 12,000 miles (19,000 kilometers) across the innermost rings tells of a very large meteoroid impact in 1983.

    “These new results imply the current-day impact rates for small particles at Saturn are about the same as those at Earth — two very different neighborhoods in our solar system — and this is exciting to see,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “It took Saturn’s rings acting like a giant meteoroid detector — 100 times the surface area of the Earth — and Cassini’s long-term tour of the Saturn system to address this question.”

    >Snip 1/2 of the article<

    Journal Reference:
    Matthew S. Tiscareno, Colin J. Mitchell, Carl D. Murray, Daiana Di Nino, Matthew M. Hedman, Jürgen Schmidt, Joseph A. Burns, Jeffrey N. Cuzzi, Carolyn C. Porco, Kevin Beurle, and Michael W. Evans. Observations of Ejecta Clouds Produced by Impacts onto Saturn’s Rings. Science, 2013; 340 (6131): 460-464 DOI: 10.1126/science.1233524

    That Saturn has the same impact rates as Earth, despite the orbital and mass differences, will be good grounds for a lot of impact rate threat re-evaluation.

  • E.P. Grondine

    What is needed is a grand accretion model for our solar system, and that will require a whole lot more data and analysis.

    I intend to confine my efforts to what I can now do, small aspects of Earth’s recent impact history, and leave this big issue for others to work on.