Scientists Locate Likely Origin For the Dinosaur-Killing Asteroid (space.com) 71
The asteroid credited with the extinction of the dinosaurs 66 million years ago is likely to have originated from the outer half of the solar system's main asteroid belt, according to new research by Southwest Research Institute (SwRI). Space.com reports: Known as the Chicxulub impactor, this large object has an estimated width of 6 miles (9.6 kilometers) and produced a crater in Mexico's Yucatan peninsula that spans 90 miles (145 kilometers). After its sudden contact with Earth, the asteroid wiped out not only the dinosaurs, but around 75 percent of the planet's animal species. It is widely accepted that this explosive force created was responsible for the mass extinction that ended the Mesozoic era. Researchers used computer models to analyse how asteroids are pulled from their orbit in different areas of the asteroid belt and drawn towards planets. The observations of 130,000 model asteroids, along with data and behaviour seen in other known impactors, found that objects are 10 times more likely to reach Earth from the outer asteroid belt than previously thought.
Prior to crashing into Earth, the extinction-causing asteroid orbited the sun with others, in the main asteroid belt. This concentrated band lies between planets Mars and Jupiter, with its contents usually kept in place by the forces of gravity. Before this study was released, scientists thought that very few of Earth's impactors escaped from the belt's outer half. But, researchers at SwRI discovered that "escape hatches" could be created by thermal forces, which pull more distant asteroids out of orbit and in the direction of Earth. The objects found in these outermost parts of the asteroid belt include many carbonaceous chondrite impactors. These are dark, porous and carbon-containing rocks which can also be found on Earth. Leading up to this research, other scientists have attempted to learn more about the object that doomed the dinosaurs. This included examinations of 66-million-year-old rocks. By doing this, geologists discovered that the Chicxulub asteroid had a similar composition to today's carbonaceous chondrites. By looking at wide timescales of the Chicxulub asteroid, the scientists could predict that a 6-mile asteroid is likely to come into contact with Earth once every 250 million years. Their model showed almost 50 percent of these significant impactors to be of the same carbonaceous chondrite composition. Details of the new study will be published in the November 2021 issue of the journal Icarus.
Prior to crashing into Earth, the extinction-causing asteroid orbited the sun with others, in the main asteroid belt. This concentrated band lies between planets Mars and Jupiter, with its contents usually kept in place by the forces of gravity. Before this study was released, scientists thought that very few of Earth's impactors escaped from the belt's outer half. But, researchers at SwRI discovered that "escape hatches" could be created by thermal forces, which pull more distant asteroids out of orbit and in the direction of Earth. The objects found in these outermost parts of the asteroid belt include many carbonaceous chondrite impactors. These are dark, porous and carbon-containing rocks which can also be found on Earth. Leading up to this research, other scientists have attempted to learn more about the object that doomed the dinosaurs. This included examinations of 66-million-year-old rocks. By doing this, geologists discovered that the Chicxulub asteroid had a similar composition to today's carbonaceous chondrites. By looking at wide timescales of the Chicxulub asteroid, the scientists could predict that a 6-mile asteroid is likely to come into contact with Earth once every 250 million years. Their model showed almost 50 percent of these significant impactors to be of the same carbonaceous chondrite composition. Details of the new study will be published in the November 2021 issue of the journal Icarus.
Way off (Score:3, Funny)
Re:Way off (Score:4, Interesting)
I still blame Klendathu.
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Or Marco Inaros ...
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Source: Gary Larson
Let me guess... (Score:4, Informative)
Probability for intelligent life (Score:5, Interesting)
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That does rather assume that no intelligent life would ever have arisen from the dinosaurs. High intelligence is a specific solution to a specific problem and how often that particular situations arises is anyones guess. If the asteroid hadn't hit dinosaurs might have gone to the moon only a few million years later. Or they may have continued just living in their ecological niches and breeding.
And tbh , intelligent as we are , we did nothing much for half a million years until agriculture and cities came al
Re:Probability for intelligent life (Score:4, Interesting)
Exactly, life is very old, it had billions of years to evolve an intelligent life and it didn't, instead an unlikely chain of periodical planet reformatting was required.
None of the life forms which existed for hundreds of millions (or even billions) of years wasn't even remotely close to the early hominids, but humans did it in merely a few hundred thousand years.
Re:Probability for intelligent life (Score:4, Interesting)
We suddenly arose from fairly dim chimp like creatures in a million years after apes had been around for a very long time and mammals for > 70 million years. There's no reason therapod dinosaurs couldn't have followed a similar path. Nothing was inevitable about our evolution.
Re:Probability for intelligent life (Score:4, Informative)
There are definitely birds (who do descend from dinosaurs) that rival plenty of similarly-sized mammals in intelligence - who knows what could hypothetically evolve from them given the right evolutionary pressures.
But the exact circumstances that allowed a specific line of mammal to go as far as we have must be rare, since no other branches of life here seem to have.
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"who do descend from" should have been spelled "are"....
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Some people find the distinction useful.
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(When did I last edit my .sig ? Probably about the turn of the millennium.)
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Agreed. Though even intelligence won't necessarily ensure your survival long term as the neanderthals and other hominids demonstrate.
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The various hominids probably occupied roughly the same niche in their ecosystems, and may have disappeared mainly due to the arrival of new competition, being assimilated, displaced or straight out killed by other groups, rather than simply failing on their own. More of a cup than a race, then. Doesn't mean the other contenders could never have gotten anywhere.
Most cultures have stories of weird humanoids lurking in the woods. Usually portrayed as extremely dangerous and our natural enemies. Makes sense th
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Yeah. The neighbours. Everyone hates and fears the neighbours - the more similar to us they are, the more they compete for the resources we need.
Your country's sports authorities doesn't award cups for single races then? Weird.
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Your country's sports authorities doesn't award cups for single races then?
Yes, but I'm also used to "cup" as shorthand for the "knockout tournament" competition form, as several of the most famous ones have "cup" in their name.
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life is very old, it had billions of years to evolve an intelligent life and it didn't, instead an unlikely chain of periodical planet reformatting was required.
You literally can not know that, because the sample size is 1, and there's no control Earth. It's also possible that an intelligent life would have evolved simply to compete with the dinos, and we don't know how much longer that would have taken if at all. But even assuming it would take longer because of the competition, that doesn't prove that it wouldn't happen.
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Humans haven't changed significantly for hundreds of thousands of years, and our tools didn't vary greatly from several million years ago until a few hundred centuries ago. And of course, we appear to be heading towards a mass extinction event of our own making!
Compare that with what went before. We have fossils of animals (including dinosaurs) which
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Since we get to define what intelligence means, all we are really saying is that animals like humans probably weren't around back then.
Define intelligence so I can agree with you.
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Unlikely, their brains were too small. Most were barely large enough to manage their bodies, especially the big herbivores who appear to have farmed out a lot of functions to secondary regions like the solar plexus. IIRC the exceptions were the bird-related therapods, which may have been as intelligent as a blue jay.
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While they were definitely smaller than mammalian brains for a similar body size (yes, it varies among mammals), how well that maps onto "intelligence" (whatever that means) is a much more open question because we also know that some of the closest extant members of the dinosaur clade - birds - are considerably more intelligent than mammals of a comparable body size. Or brain size.
Clearly, there are at least two, significantly different, ways of achieving whatever we
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None of the life forms which existed for hundreds of millions (or even billions) of years wasn't even remotely close to the early hominids...
We don't know that, and have no way of of knowing either.
It is entirely possible that tool making intelligences have arisen multiple times and never got beyond the stone age before becoming extinct.
If that happened 200 million years ago what traces would they have left?
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An unpredictable chain of events happened. Whether it was required is a distinct question. We'd need at least a couple of counter examples (of about 4Gyr of evolution, but with fewer major extinction events, and no (or less) evidence of intelligence) to have any degree of the confidence you imply.
Unless, of course, you have access to infor
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Seeming that 70% of the worlds oil comes from the Mesozoic age my guess is that even if they were intelligent they would have struggled to get past the building small cities phase and definitely wouldn't have been able to forge steel without oil, coal etc
Re:Probability for intelligent life (Score:4, Funny)
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Yes, but AFAIK most coal comes from the cambrian era and it was coal that started the industrial revolution, not oil.
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I'm still having a problem envisioning a tyrannosaurus rex swinging a hammer with those little hands and arms.
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I've drilled oil deposits of Miocene, Eocene, Palaeocene, Cretaceous, Jurassic, Permian, Carboniferous, and Cambrian age. The oil-forming process has been going on for as long as there have been accumulations of organic matter for it to act on. There have been tracer molecules (most easily formed from thermally decomposing chlorophyll molecules) found in Archean sediments, sugg
Re: Probability for intelligent life (Score:2)
Re: Probability for intelligent life (Score:2)
10K+ years until someone could forge steel well enough to make a steam engine out of
Ahm, maybe, but it took the dinosaurs and their extinction for the guy who forged the steam engine to actually have the coal to... you know... drive it :-)
You could reply that coal can (and in fact was, at times, made from live wood). But (1) that's nowhere near the energy density that fossil fuels have. Gasoline and diesel even more so. And (2), here we are: essentially having burned through two biospheres (ours and the dinosaurs), and then some (the 65 mio years of high-pressure rotting), and only now hav
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Uh, I believe most of the oil was from plants. If it was dinosaurs, there would have to have been a lot more of them.
Re: Probability for intelligent life (Score:2)
That's semantics.
Strictly speaking, most dinosaurs didn't die in the fireball. They died because they ran out of plants, then the rest died because they ran out of prey.
Doesn't change the fact that we wouldn't be "us" were it not for that mass extinction event.
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Very clearly it was. The large majority of oil deposits contain biomarker molecules formed by the decomposition of plant cell walls, less contain biomarkers from animals (or for that matter, fungi). Long-chain fatty acid molecules such as form waterproof coatings on leaves are particularly common.
It's not a 100% : 0% thing - more like 80% : 20%, but it's clear enough to be a predictive tool well proven in exploration work.
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That does rather assume that no intelligent life would ever have arisen from the dinosaurs.
We have not yet seen enough of the solar system to be sure that they didn't:
https://en.wikipedia.org/wiki/... [wikipedia.org]
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I can't stop wondering what an absolutely incredible, impossible chain of random, catastrophic events during it's entire history caused the Earth to produce humans, and yet we are here. It's simply mind boggling.
Multiply an infinitesimal chance by an infinite number of planets, and you still have an infinite number of worlds with intelligent life. Just very far apart.
Our existence is a dead certainty, even if it is almost impossible on any given world. Not that this makes life, or the multiverse, any less awesome.
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And your evidence for a multiverse is what, precisely? You are also assuming the Universe is infinitely large. And multiplying an infinitesimal probability by anything results in an infinitesimal, hence the name "infinitesimal".
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Pick any event you like. The chances of it happening over the 13.6 billion years since the Big One is small. Calling it "The Origin of Life" doesn't make it any more or less probable than any other event.
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Yeah, that idea was still circulating in the late 20s (1920s, not 2020s) as a viable thing. As celestial mechanics (or rather, the ability to do the maths time and again) improved it quietly died through the 1950s, leaving the molecular-cloud origin as pretty much the only optio
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Obviously we didn't start out this way, we've evolved to this through continuous iterations.
The exact evolutionary pressures that got us to an exaggerated level of intelligence, who knows, probably intense competition with each other. What else could we have been evolving to outsmart? At some point, dumb people must have died young. Whatever it is, we're past it, because being more intelligent isn't rewarded with extra slots in the gene pool now. That was our shot. At this point we can talk about how a
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That's one end of the Drake Equation, certainly. https://en.wikipedia.org/wiki/... [wikipedia.org]
Is F-sub-i vanishingly small, or nearly 1.0?
I think the statistical sample we have (earth =1) would suggest that LIFE is ubiquitous. It's everywhere here, and the earth has been repeatedly pounded so brutally that it's nearly wiped away this greasy organic film on its surface several times....but still it flourishes back.
I believe we're certain to find all varieties of fungi, lichens, mosses, even up to prokaryotes throughou
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Either we are alone or we are a part of some grand master plan which does not imply randomness at all.
Re: 6000 years old (Score:2)
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There is this 'creation' museum...
Yeah, we have one close by here in the midwest, you can hear the knuckles dragging when they walk. I asked my future ex-wife "how old is the earth" she said 42, I had to give her credit for studying the problem.
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False. Every one that I've met says that dinosaurs roamed the earth and interacted with humans prior to Noah and the flood, and that Satan altered the bones to mess up carbon dating.
Re: 6000 years old (Score:2)
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Ya, well G-d is a FUNNY god. Burying all those dino bones wasn't easy but He knows a good joke when He sees one.
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Read "Strata" by Terry Pratchett.
https://en.wikipedia.org/wiki/... [wikipedia.org]
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Everyone knows.. (Score:2)
Get me out of here! (Score:2)
Re: Get me out of here! (Score:2)
Ahhhhh! (Score:3)
By looking at wide timescales of the Chicxulub asteroid, the scientists could predict that a 6-mile asteroid is likely to come into contact with Earth once every 250 million years.
(Checking the calendar) That's tomorrow!
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One of the tiny problems with that is that there are at least TWO astroblemes from ~6km impactors known within the last 250Myr. And with well over half of the Earth's surface being subducted in that period, you can expect at least two more undetected / undetectable impacts of the same sort of size.
Oh my god, how old am I? (Score:2)
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FTFYThese days the uncertainty is down to +/- 1Myr - things are improving. But we still don't know with any confidence if the impactor happened before, during, or after the Deccan Traps volcanic eruptions - which themselves took around 1 Myr to start, have two peaks of intensity, then finish.
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Let's Get Over Models (Score:2)
One only needs to look at storm tracking models to see how widely results can come in. https://www.cyclocane.com/spag... [cyclocane.com]
Yes, they can be helpful, but are frequently WAY off. Garbage in/Garbage out
The article is a joke (Score:2)
So I follow their lead.
How did the cavemen survive the asteroid that killed all the dinosaurs?
Social distancing, they stayed 56 million years apart.
A guy and his friend are sitting on a sofa having a few beers. Guy #1 - “What would you do if we found out an asteroid was going to hit the earth in one hour?”
Guy #2 - “I would fuck the first thing that moved. What would you do?”
Guy #1 - “I’d sit very fucking still for the next hour!”
Why was Jupiter banned from competing
An interesting thought: (Score:2)
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