May
21
2007

Another ET collision may have impacted megafauna

Mega-victim of mega-collision?: Mammoth skeleton on display at the American Museum of Natural History. Photo courtesy Mark Ryan.
Mega-victim of mega-collision?: Mammoth skeleton on display at the American Museum of Natural History. Photo courtesy Mark Ryan.
A new theory suggests that a blast from space 13,000 years ago may have been responsible for changes in Ice Age human cultures, and for wiping out most of North America’s large mammals, a fate similar to what large dinosaurs may have met 65 million years earlier.

The extraterrestrial blast from a large object, such as a comet or asteroid, colliding with Earth would have caused a significant climate cooling over the North American continent lasting for centuries.

According to Dr. Richard Firestone of Lawrence Berkeley National Laboratory, in California, the source of the collision may have originated from a supernova explosion that occurred about 250 light years from Earth.

“Our research indicates that a 10-kilometer-wide comet, which may have been composed from the remnants of a supernova explosion, could have hit North America 13,000 years ago,” says Firestone. “This event was preceded by an intense blast of iron-rich grains that impacted the planet roughly 34,000 years ago.”

Firestone and co-researcher Alan West say evidence of the supernova’s initial shockwave can be found in tiny impact craters in 34,000 year-old mammoths tusks. The two men theorize the tiny craters are the results of iron-rich grains traveling at 10,000 kilometers per hour slamming into the enamel.

Other evidence supports the comet impact theory. Sediment layers at some 22 prehistoric sites across the continent, show high of levels of iridium, along with concentrations of tiny diamond chips called nanodiamonds. There’s also a black layer of high carbon content that researchers argue could be the remains from wildfires ignited by the blast that swept across the continent.

No crater is known but scientists suggest that ice sheets present at the time may have been thick enough to act as a buffer against the collision.

It’s also possible the space rock exploded in the atmosphere but even then a shockwave of intense heat that would have wiped out everything in its path for miles around, and would have caused immediate and long-term damage to any existing human cultures. Glacial ice would have melted and surged into the North Atlantic, changing currents and effects on climate for centuries.

Such an event seems to coincide with the onset of what’s known as the Younger Dryas Episode, a period of significant environmental changes, Paleolithic cultural development, and mega-fauna extinctions.

All the large mammals that once populated the North and South Americas disappeared suddenly right about the estimated time of the extra-terrestrial impact.

"All the elephants, including the mastodon and the mammoth, all the ground sloths, including the giant ground sloth - which, when standing on its hind legs, would have been as big as a mammoth," said Professor James Kennett, from the University of California in Santa Barbara.

"All the horses went out, all the North American camels went out. There were large carnivores like the sabre-toothed cat and an enormous bear called the short-faced bear."

The effects of such a sudden extinction would certainly impact human populations as well. And that seems to be what happened. A number of prehistoric cultures such as the Clovis seem to have disappeared around the same time.

The new theory will be presented and hashed out this week at the American Geophysical Union's Joint Meeting in Acapulco, Mexico.

LINKS AND MORE INFO

BBC story
Hot Springs, SD Mammoth Site
American Geophysical Union website
Younger Dryas Info
More Younger Dryas Info
Extraterrestrial Impacts

Your Comments, Thoughts, Questions, Ideas

Anonymous's picture
Anonymous says:

Balderdash

posted on Wed, 05/23/2007 - 2:27pm
Tori.j's picture
Tori.j says:

This is a very interesting theory and I think we should really look into it.

posted on Wed, 10/17/2007 - 11:03am
Dennis Cox's picture
Dennis Cox says:

I am just a layman. But this this may be the blast structure of the YD impact event:

http://theholocenecomet.spaces.live.com

Take a look.

posted on Sun, 01/25/2009 - 7:05pm
mdr's picture
mdr says:

Thanks Dennis for posting this link. You may be right.

posted on Mon, 01/26/2009 - 10:43am

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