Posted on 03/10/2013 3:10:46 PM PDT by BenLurkin
comet crashing into the Earth some 13,000 years ago was thought to have spelled doom to a group of early North American people, and possibly the extinction of ice age beasts in the region.
But the space rock was wrongly accused, according to a group of 16 scientists in fields ranging from archaeology to crystallography to physics, who have offered counterevidence to the existence of such a collision.
Almost 13,000 years ago, a prehistoric Paleo-Indian group known as the Clovis culture suffered its demise at the same time the region underwent significant climate cooling known as the Younger Dryas. Animals such as ground sloths, camels and mammoths were wiped out in North America around the same period.
In 2007, a team of scientists led by Richard Firestone of the Lawrence Berkeley National Laboratory in California suggested these changes were the result of a collision or explosion of an enormous comet or asteroid, pointing to a carbon-rich black layer at a number of sites across North America. The theory has remained controversial, with no sign of a crater that would have resulted from such an impact.
"If a four-kilometer (2.5-mile) comet had broken up over North America only 12.9 thousand years ago, it is certain that it would have left an unambiguous impact crater or craters, as well as unambiguous shocked materials," Boslough said.
Boslough, who has spent decades studying the effects of comet and asteroid collisions, was part of a team that predicted the visibility of plumes from the impact of the 1994 Shoemaker-Levy 9 comet with Jupiter.
"Comet impacts may be low enough in density not to leave craters,"
He also points to independent research ...... that indicates such explosions could have come from a debris trail created by Comet Encke, which also would not have left a crater.
(Excerpt) Read more at science.nbcnews.com ...
IIRC, one theory was that the reason it left no crater is because it impacted a glacial ice sheet.
One the glacier melted, any crater would have melted with it.
Mayans.
Methinks the reporter is misunderstanding things. AFAIK there is zero evidence the Clovis culture people were wiped out, only that their culture, supposedly based on the hunting of megafauna such as mammoths, disappeared when the megafauna went away.
The people presumably then altered their way of life to the point where they were no longer the "Clovis culture" people.
BTW, the traditional POV, now non-PC, is that the Clovis culture people and other early Indians wiped out the megafauna by overhunting, and possibly by "managing" the landscape with fire. I've always been skeptical of that notion myself, though I do enjoy watching it make liberals sputter. And the timing of the disappearance of megafauna all over the world does seem to have a close correlation to the appearance of humans in those areas.
Doubt it. A 4k meteor would hardly be even slowed by a 2 to 3 mile thick ice sheet.
It would release energy of 3.47 x 10 to the 6th megatons of TNT. The largest H-bomb ever built was 57 megatons.
Ice isn’t going to do much to affect that.
Here’s a neat impact calculator.
http://impact.ese.ic.ac.uk/ImpactEffects/
The Clovis elected a socialist chieftain which led to their demise.
Invention of excessively-sized sugary drinks
“Spelled doom to a group of early North American people.” The poor bas**rds had to sit through a spelling bee? No wonder they died.
That's why the Liberals are desperate to find a comet or asteroid to blame all those extinctions on, they need it to keep their Noble Savage myth going.
To believe it was not man, you would have to believe that whenever man first showed up at a new location, by some amazing coincidence an asteroid or comet always would soon hit in the same exact location wiping out the local megafauna.
Thank you. I got a chance to,destroy the earth, again.
Well obviously these humans polluted the atmosphere so much with their excessive CO2 emissions that the climate started cooling - just like is happening today ....
/Al Gore mode
“The Clovis elected a socialist chieftain which led to their demise.”
The tragedy of that was that the son-of-a-gun wasn’t even eligible and hated Clovis people from the get-go.
Oldplayer.
Agree and disagree about the crater. An ice sheet would have quickly obscured the surface expression of the crater due to erosion and sedimentation. I do believe that the shatter cones and other bedrock effects of the impact would still be present, several of which are quite distinct. To my knowledge none of these have been found.
Thanks for the calculator. At a few thousand miles away, at least a 5-mile diameter meteor would be required for coolness and a good time, IMO. [Note to self: remember crash helmet, improvised padding and bandanna for dust.] ;-)
I'm not sure what evidence could be expected from a very low angle 3-4 km diameter bolide break-up moving South to North.
To believe man was responsible you would have to believe that small groups of hunter-gatherers in N. America were responsible for the destruction of mammoths, mastodons, giant bison, horses, camels, harrington's mt. goat, american cheetahs, american lions, american mt. deer, short-faced bears, smilodons, the giant cave bear, the woodland muskox, the giant ground sloths, dire wolves, the Stag-moose, the giant armadillo, and on and on and on...
The extinction list is way too long and diverse (including birds and reptiles) to simply tack it onto the butcher's bill of humans. Correlation is not causation.
Extend the argument to it logical absurd conclusion. If man could wipe out mega-fauna as soon as they arrived, then why are there any animals in Africa where man was present many many years before in the Americas.
The Cycle of Cosmic Catastrophes:
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone,
Allen West, and
Simon Warwick-Smith
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