Collision in Asteroid belt may have condemned dinosaurs

MeteorWayne · Sep 6, 2007

BBC link SDC link Space pile-up 'condemned dinos' The collision would have occurred in the asteroid belt. A colossal collision in space 160 million years ago set the dinosaurs on the path to extinction, a study claims. An asteroid pile-up sent debris swirling around the Solar System, including a chunk that later smashed into Earth wiping out the great beasts. Other fragments crashed into the Moon, Venus and Mars, gouging out some of their most dominant impact craters, a US-Czech research team believes. The analysis shows, the team says, that one large shard from the break-up probably created the 85km-wide Tycho impact crater on the Moon 108 million years ago. Its study, based on computer modelling, is reported in the journal Nature. The results, published in the Sept. 6 issue of the journal Nature, rely on a series of computer models and do not represent a firm conclusion, though they are supported by information collected from the Chicxulub crater by past researchers. "There are an awful lot of models that are required in order to come to the conclusion," said Jay Melosh of the Lunar and Planetary Laboratory at the University of Arizona in Tucson, who was not involved in the current study. "I don't find any of them implausible and the conclusion seems to be plausible." He added, "I don't have any problems with the models, but they are models." Edited typo in thread title. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

yevaud · Sep 6, 2007

I see. So they've backtracked using modeling, and believe a larger body once existed, fragmented due to a collision, and that the calved fragments were responsible for Chixlub, Tycho, and a few other prominent craters? Sure, why not. It's possible, though I am always moderately suspect of models during a theory's initial stages. <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

3488 · Sep 6, 2007

True it is a model, a very highly plausible one. Worth following up. I always thought it quite strange that the Chicxulube Crater in Mexico & Tycho on the Moon being of similar ages. What about craters on Mars & Mercury too? Thanks MeteorWayne. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

MeteorWayne · Sep 6, 2007

I agree, that's why I copied the disclaimer over from the one article to create my post. However, if there are indeed ways to tie this asteroid family together chemically with Chixalub, it would strengthen the case. I'll be sitting by the mailbox waiting for Nature this week <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

MeteorWayne · Sep 6, 2007

Once I read the article, I'll let you know how that question is addressed. It's pretty useless to try and extract too much detail from news reports <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

hlbuz · Sep 6, 2007

The main question for me, is how long before the impact was the actual collision of the asteroids? Did the rubble orbit the sun for a couple hundred years before hitting us or was it just a matter of days? Can the model provide a clue? Thx

MeteorWayne · Sep 6, 2007

The proposed impact occurred ~160 million years ago. The Tycho crater on the moon was formed ~ 100 million years ago Chixalub on earth occurred ~ 65 million years ago. So this material took between 60 and 100 million years to intersect the earth-moon system, and if I read it right, there still could be asteroids from this collision with our name on it; though we haven't discovered any yet. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

MeteorWayne · Sep 6, 2007

Newtonian and Keplarian mathematics. With the increase in computing power over the last decade, you can now run very precise models of the movevment of solar system objects. Both forward and backward in time. If it gets chaotic, then you know the prediction can't be trusted as accurate, but if it stays stable for hundreds of millions of years, then you know the solution is robust (unlikely to be much different that the precise prediction) It is really very simple math, if you can do it accurately and fast enough to be useful. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

MeteorWayne · Sep 6, 2007

Sorry, anvel, I don't think that's true. If the effects of the collison are stable orbits (backtracked in time), then 100,000 years makes no difference on millions of year timescales. I suspect they are not saying that obect 547B impacted earth on March 14th, 65,132,437 BC. They are suggesting that due to the evolution of orbits over tens of millions of years. (and the key is such objects getting into resonant orbits with Jupiter), that the likelyhood was very high that objects from this collision could have impacted the earth and moon during this period. Otherwise, such impacts are quite unlikely. The asteroid belt is surprisingly stable. Further evidence could come from Mars, Venus and Mercury as well, now that they have suggested something to look for. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

jaxtraw · Sep 6, 2007

I'm just wondering how the cue ball got in that crazy orbit in the first place... <img src="/images/icons/smile.gif" />

MeteorWayne · Sep 6, 2007

Well, again, I'm basing this on the news reports, which is no substitute for the actual research, but IIRC it was suggested the impactor had a very high inclination. Striking the main belt asteroid from above, well out of the plane of the main solar system. (Solar equator, 8 planets, dwarf planets, asteroid belt, Plutinos, Kuiper belt) This would make the most likely culprit an object from the Oort cloud; either a large comet, or possibly something in the asteroid/dwarf planet class. I have to wait for the mail so I can read the article <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

jaxtraw · Sep 6, 2007

Well, catastrophism is "in" at the moment and it seems there's quite a lot of enthusiasm for tying one's hypothesis, however speculatively, into some kind of headliner (e.g. "this ancient civilisation collapsed due to environmental degradation/climate change" or "this caused the death of the dinosaurs".) We can only hope that science will go through a bit of a paradigm shift and retreat back into a more cautious approach once global warming goes into the Oops Bin along with eugenics and land bridges.

MeteorWayne · Sep 6, 2007

If you do the math, there's no reason to be incredulous. I realize that you can't do me math (nor can I) without the help of supercomputers There are a half dozen asteroid families that have been derived from impacts within the asteroid belt. The results are very strong. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

3488 · Sep 6, 2007

Computer problems are fixed. Blooming virus, not a faulty connection. Anyway, I have reading this thread with great interest. I can understand the scepticsm, but I think this is based on good science. Granted, the majority of the asteroid belt is stable. What we are forgetting with the possible exception of MeteorWayne are these points. 1). The giant asteroid 2 Pallas is inclined by approx 34 degrees & 48' to the plane of the asteroid belt & is in a highly eccentric orbit of 0.23. Why is such a giant asteroid in such a highly inclined, eccentric orbit? 2). As pointed out already, asteroid 4 Vesta has been walloped hard, sporting a gigantic south polar crater, complete with a 13,000 metre / 42,600 foot tall central mountain. 3). A great many asteroids are rotating on their sides, like the planet Uranus, some examples: 2 Pallas, 7 Iris, 8 Flora, 16 Psyche, 21 Lutietia, 22 Kalliope, 45 Eugenia, 433 Eros, 511 Davida & 951 Gaspra. 4). There are asteroid families, where asteroids share common orbital characteristics & even spectral types, such as the Koronis Family, which asteroid 158 Koronis is thought to be the parent & 243 Ida is thought to be a member. What created the asteroid families? Collisions!!!! 5). Our Sun orbit's the centre of the Milky Way, once every 225 million years, taking the planets, etc with it. At times, there will be close approaches of other stars, which will cause disturbances, particularly further out from the Sun, where the Sun's pull is weaker. 6). Worth bearing in mind that something appeared to cause the Jupiter moon Ganymede to leave a circular orbit into a more elliptical one, thus reheating the interior temporarily, about 1GYA. What caused that? 7). Many KBOs are in steeply inclined orbits. Pluto by about 17 degrees, Eris even more so @ 44 degr <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

jaxtraw · Sep 6, 2007

I'm not sceptical about the collision, but I am sceptical about the headline-grabbing linkage to the world's most famous impact crater. It seems to me inherently dubious for scientists to link a possible collission in the asteroid belt to an impact 100 Mya later which just happens to be the exciting dinosaur-killer one. It smacks really of sensationalism. I'll admit that it's an issue for me; I'm concerned at the degradation of science as scientists scramble over one another to the press to grab headlines over studies that, when one reads them thoroughly, are rarely anywere near as conclusive as the press release declares. The medical community for instance are particularly bad with this, with headlines blaring that e.g. eating brussels sprouts prevents dropsy of the liver; then if you look at the paper it's a weak statistical inference that is probably due to chance; the awful triumph of the (RR 1.2, CL95%) brigade. Sorry, I'm ranting. What we have here is a computer model that shows a collision may have occurred in the asteroid belt 160Mya ago; all well and good. "May be the dinosaur killer" isn't science at all, just wild speculation. But hey, it looks good as a headline, please give us another grant and we'll tune our model a bit, etc, etc...

3488 · Sep 6, 2007

Hi jaxtraw, Do not get me wrong. I agree with you 100% about the media hyping up stuff. I have a medical condition, quite serious in some ways, that caused me nothing but endless difficulties in my childhood. Another conditionI have has at times made me feel like ending my life. How do you think I felt when the media, due to flawed information from a headline seeking doctor, made mothers not have their children immunised. The media was on & on about this for months. There are vested interests in all of the sciences, so Astronomy is not immune from that. I had to stick up for MeteorWayne, because he is an authority on this sort of thing & if he thought this was crap, he would have made that quite plain or not even bothered. Unfortunately anything surrounding the most famous impact site on Earth, will be headline grabbing. What would be most useful, would be if actual samples from the impactor could be found. Than to see if impact material could be identified from the old Surveyor 7 images / data, near Tycho on the Moon & see if comparisons can be made. Below: Surveyor 7 view, just north of Tycho. Is this landscape, related to the same event that killed the dinosaurs???????? NASA / AMES. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

thebigcat · Sep 7, 2007

3488: How do you think I felt when the media, due to flawed information from a headline seeking doctor, made mothers not have their children immunised. Me: And I noticed a headline today. Apparently teen suicides are up markedly and they are placing the fault on earlier headlines linking teen suicides with antidipressants. It seems that so many parents read the earlier headlines and took their kids off the antidipressants. Simple math, really. With the antidipressants you kid has a 1 in 100,000 chance of suicide, without them he has a 1 in 1000. The numbers are made up to illustrate the point, of course, but yeah...silly press. [/threadjack] Now back to the topic. I was under the impression that all of the Earth-Crossers, and this includes the K-T asteriod, are generally held to be the debris from the impact which created the moon. The greatest proof of this is the crystaline structure of the iron-nickel of which most solid asteroids are composed. The structure shows that it was cooled in the heat-sink of space but it could never have accumulated into such a high concentration unless it had originally formed in the gravity well of a planet. When we get out to the asteroids beyond Mars orbit and can do some actual surveying of the structures, if we find that the vast majority of the asteroids out there are accretion bodies it will almost certainly confirm this theory of the origin if the ECOs. <div class="Discussion_UserSignature"> </div>

MeteorWayne · Sep 7, 2007

AFAIK, your impression is incorrect. Most current earth crossing asteroids do in fact result from collisions within the asteroid belt. I found more about this story from NEO news. "The Baptistina asteroid shower continues to threaten the Earth. It produced at least 1,000 smaller asteroids at least 1km in diameter, and between a fifth and a third of the near-Earth objects that cross our planet's orbit. A strike from a 1km object would cause devastation on a continental stage and threaten the survival of civilisation, while another 10km impact would have the same effect it did 65 million years ago. Such an event remains very unlikely. Though the Baptistina break-up is thought to have doubled the rate at which large asteroids strike the Earth, only one 10km object collides with the planet every 350 million years. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

MeteorWayne · Sep 7, 2007

Well, as I understand it, that connection was indeed part of the Nature article, but will have to hold of judgement until I actually read it. Nature usually comes on Friday for me, so I'm hopeful it will arrive today <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

alokmohan · Sep 7, 2007

This one from astronomy magazine may help.he impactor believed to have wiped out the dinosaurs and other life forms on Earth some 65 million years ago has been traced back to a breakup event in the main asteroid belt. A joint U.S.-Czech team from Southwest Research Institute (SwRI) and Charles University in Prague suggests that the parent object of asteroid (298) Baptistina disrupted when it was hit by another large asteroid, creating numerous large fragments that would later create the Chicxulub crater on the Yucatan Peninsula as well as the prominent Tycho crater found on the Moon. The team of researchers, including Dr. William Bottke (SwRI), Dr. David Vokrouhlicky (Charles University, Prague) and Dr. David Nesvorny (SwRI), combined observations with several different numerical simulations to investigate the Baptistina disruption event and its aftermath. A particular focus of their work was how Baptistina fragments affected the Earth and Moon. At approximately 170 kilometers in diameter and having characteristics similar to carbonaceous chondrite meteorites, the Baptistina parent body resided in the innermost region of the asteroid belt when it was hit by another asteroid estimated to be 60 kilometers in diameter. This catastrophic impact produced what is now known as the Baptistina asteroid family, a cluster of asteroid fragments with similar orbits. According to the team's modeling work, this family originally included approximately 300 bodies larger than 10 kilometers and 140,000 bodies larger than 1 kilometer. Once created, the newly formed fragments' orbits began to slowly evolve due to thermal forces produced when they absorbed sunlight and re-radiated the energy away as heat. According to Bottke, "By carefully modeling these effects and the distance traveled by different-sized fragments from the location of the original collision, we determined that the Baptistina breakup took place 160 million years ago, give or take 20

MeteorWayne · Sep 7, 2007

Thanx for the repeat of what we've been talking about, though since you copied the whole article at astronomy, it did add some detail. Where is the link? Again, this is all second hand information until I have Nature beneath my reading glasses. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

alokmohan · Sep 7, 2007

http://list.astronomy.com/UM/T.asp?A33.171.170.1.13491072

MeteorWayne · Sep 7, 2007

Thank you. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

3488 · Sep 7, 2007

A little bit about the offending asteroid. Asteroid 298 Baptistina, is thought to be the largest fragment of the original 170 KM / 110 mile diameter asteroid. Asteroid 298 Baptistina is approx 30 KM / 19 miles across. It is a type C (Carbonaceous) asteroid. Perihelion: 2.04 AU. Semimajor: 2.26 AU. Aphelion: 2.48 AU. Orbital period: 3 years & 149 days. Orbital Inclination. 6 deg 16'. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

MeteorWayne · Sep 7, 2007

Thanx for researching that Andrew. I'm tied up with a Peresids presentation at the NJAA tonight, so haven't had time to do it. Gracias, my friend. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

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