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Asteroid Breakup May Have Doomed Dinosaurs
Centauri Dreams ^ | 9/5/07

Posted on 09/05/2007 11:55:02 AM PDT by LibWhacker

It’s a disaster scenario that Hollywood has picked up on (think Deep Impact). An incoming object menaces the Earth. Scientists try to destroy it with nuclear weapons, but the horrified populace soon discovers that the blast has simply broken the object into pieces, each with the potential to wreak havoc planet-wide. Now we learn that an impact between two asteroids causing a similar crack-up may have resulted in the cataclysmic event some 65 million years ago that destroyed the dinosaurs.

Researchers from Southwest Research Institute and Charles University (Prague) have been studying the asteroid (298) Baptistina, combining their observations with numerical simulations to model the impact event. As the theory goes, Baptistina’s parent body, some 170 kilometers in diameter, was hit by another asteroid approximately 60 kilometers wide. The result: The Baptistina asteroid family, a cluster of fragments in similar orbits that once included 300 bodies larger than 10 kilometers and 140,000 bodies larger than one kilometer.

Asteroid strike on Earth

With all the characteristics of a carbonaceous chondrite meteorite, the Baptistina parent asteroid makes a nice match for the impactor that created the Chicxulub crater in the Yucatan. Sediment samples show that it, too, had a carbonaceous chondrite composition, and the team’s simulations produced a ninety percent probability that it was indeed a member of the Baptistina family. Moreover, the simulations indicate that the lunar crater Tycho may also have been produced by an impactor with a Baptistina pedigree.

The original breakup is thought to have occurred some 160 million years ago, after which the fragments’ orbits would have evolved as they absorbed sunlight and re-radiated energy away as heat. Many of the fragments escaped the main asteroid belt and became potential Earth-crossers. The researchers believe that about two percent of these objects actually went on to strike Earth. Call it the ‘Baptistina bombardment,’ a surge in impacts that peaked 100 million years ago.

“We are in the tail end of this shower now,” says William Bottke (Southwest Research Institute). “Our simulations suggest that about 20 percent of the present-day, near-Earth asteroid population can be traced back to the Baptistina family.”

The impact histories of both Earth and Moon seem to support the supposition, showing a two-fold increase in the formation rate of large craters over the past 100 to 150 million years. That should make an emphatic point about the asteroid belt: Its history of collision and orbital change may well play a significant role in the history of our planet. We need to develop and deploy the tools that can alter the orbits of potential impactors, or do we want to assume that our inadequate catalog of Earth-crossing objects will give us time enough to act?

The paper is Bottke et al., “An asteroid breakup 160 Myr ago as the probable source of the K/T impactor,” Nature 449 (September 6, 2007), pp. 48-53 (abstract).


TOPICS: Miscellaneous
KEYWORDS: asteroid; baptistina; bolide; breakup; catastrophism; chicxulub; chondrite; cretaceous; dinosaur; dinosaurs; godsgravesglyphs; impact; paleontology; stalactites; stalagmites; tertiary
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To: LibWhacker

Yep.. breakups are hard on everyone.. LOL


21 posted on 09/05/2007 12:39:00 PM PDT by MD_Willington_1976
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To: LibWhacker

You know what makes liberals mad? The fact that Dinosaurs died and made room for man.


22 posted on 09/05/2007 12:40:49 PM PDT by dragonblustar (Freedom of Speech is for everyone, not just liberals.)
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To: presidio9

Once I figured out how to get the straight jacket off, the orderlies weren’t that hard to out-run.
______________

My problem is the opposite. They keep trying to take the thing off and I keep trying to put it back on. I’ve really been enjoying the Barnaby Jones reruns they show here at the, uh, farm.


23 posted on 09/05/2007 12:46:28 PM PDT by dmz
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To: CharlesWayneCT

Stellar couple breaks up: pet dinosaurs hit hardest!!


24 posted on 09/05/2007 12:49:45 PM PDT by Hoffer Rand
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To: Hoffer Rand

The odds of two asteroids in the vastness of space colliding within the gravitational pull of earth has to be monumentally hugh.


25 posted on 09/05/2007 12:55:31 PM PDT by traderrob6
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To: traderrob6

And I STILL love how these ‘asteroids’ only targeted dinosaurs! All other life on this planet escaped harm...


26 posted on 09/05/2007 1:06:13 PM PDT by KingRonnie9
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To: KingRonnie9
All other life on this planet escaped harm...

What gives you this idea?

27 posted on 09/05/2007 1:16:46 PM PDT by js1138
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To: KingRonnie9
these ‘asteroids’ only targeted dinosaurs! All other life on this planet escaped harm...

Um, that's not exactly how things are supposed to have happened...

28 posted on 09/05/2007 1:47:48 PM PDT by presidio9 (Islam is as Islam does.)
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To: LibWhacker

YEC INTREP


29 posted on 09/05/2007 1:49:11 PM PDT by LiteKeeper (Beware the secularization of America; the Islamization of Eurabia)
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To: Thud

fyi


30 posted on 09/05/2007 1:49:21 PM PDT by Dark Wing
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To: SirLinksalot
What about the theory that they mostly died of a global deluge ?

That religious belief was abandoned by early creationist geologists--who were trying to prove the global flood--about 1830.

31 posted on 09/05/2007 1:55:52 PM PDT by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: Coyoteman
That religious belief was abandoned by early creationist geologists--who were trying to prove the global flood--about 1830.

Name names please.
32 posted on 09/05/2007 1:57:14 PM PDT by SirLinksalot
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To: SirLinksalot
That religious belief was abandoned by early creationist geologists--who were trying to prove the global flood--about 1830.

Name names please.

Reverend Adam Sedgwick, Woodwardian Professor of Geology at Cambridge University, and President of the Geological Society of London.

An article describing the capitulation of the last major holdout for the global flood in geology (made during a speech on February 18, 1831) appears here.

33 posted on 09/05/2007 2:17:24 PM PDT by Coyoteman (Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.)
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To: Coyoteman
An article describing the capitulation of the last major holdout for the global flood in geology

All we can say is this ONE man capitulated. But to say he is the last major holdout ignores the fact that we have major groups still in existence today who have not capitulated and are in fact still trying to prove this theory.
34 posted on 09/05/2007 2:21:11 PM PDT by SirLinksalot
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To: SirLinksalot

Names, please.


35 posted on 09/05/2007 2:32:18 PM PDT by LibWhacker
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To: SirLinksalot

Must’ve been raining iridium that day!


36 posted on 09/05/2007 2:35:14 PM PDT by LibWhacker
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To: LibWhacker
Rusty: Do you have Asteroids?

Dale: No, but my dad does. He can't even sit on the toilet some days.

37 posted on 09/05/2007 2:36:36 PM PDT by steveo (Time flies like an arrow, fruit flies like a banana.)
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To: CatoRenasci
I never read him so I can't say. Wasn't he writing about planets and not asteroids in particular?

I'm not saying planets can't collide (in fact they now think that's how the moon was created), but that was very early in the history of the solar system. I think mainstream scientists believe things have been pretty stable since those early days of the "heavy bombardment," at least when it comes to planets.

38 posted on 09/05/2007 2:41:03 PM PDT by LibWhacker
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To: LibWhacker

39 posted on 09/05/2007 2:43:11 PM PDT by Jonah Hex ("How'd you get that scar, mister?" "Nicked myself shaving.")
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To: Rummyfan
Nope, we're talking about evidence-based science.
40 posted on 09/05/2007 2:43:21 PM PDT by LibWhacker
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