UK Daily Mail
Fri, 02 Apr 2010 18:09 UTC
The catastrophe was caused by a disintegrating comet and saw the planet sprayed by thousands of frozen boulders made of ice and dust.
The collisions wiped out huge numbers of animal species all over the world, disrupted the lives of our stone age ancestors and triggered a freeze that lasted more than 1,000 years.
The theory is the brainchild of Professor Bill Napier, from Cardiff University, who says it explains the mysterious period of extinction around 11,000 BC.
Scientists have long been puzzled by what caused a sudden cooling of up to 8C (14F) just as the Earth was warming up at the end of the last ice age.
The change in climate caused retreating glaciers to advance once again, and coincided with the extinction of 35 families of North American mammals.
Some geologists have argued that the world was hit by a giant asteroid - a smaller version of one which wiped out the dinosaurs 65 million years ago.
The collision left behind tell-tale traces in the rocks - including a black 'mat' of soot an inch thick thought to have been created by continental wide wildfires.
Microscopic 'nanodiamonds' created in massive shocks and only found in meteorites or impact craters have also been discovered dating back to the disaster.
These findings have led to claims that a 2.5 mile long comet or asteroid smashed into the ice sheet covering what is now Canada and the northern US.
But other scientists say the chances of the Earth being struck by such a large object only 13,000 years ago are one thousand to one against. And they say a single impact cannot explain such widespread fires.
Professor Napier's theory suggests the devastation took place when the Earth strayed into a dense trail of fragments shed by a large comet.
The impacts would have filled the atmosphere with smoke and soot and blotting out the Sun.
Prof Napier says a comet swooped into the inner solar system between 20,000 and 30,000 years ago and has been breaking apart ever since.
'A large comet has been disintegrating in the near-Earth environment for the past 20,000 to 30,000 years and running into thousands of fragments from this comet is a much more likely event than a single collision,' said Professor Napier.
His model, published in the journal Monthly Notices of the Royal Astronomical Society, suggests that the 'hailstorm' would have only lasted about an hour.
It would have caused thousands of impacts, generating global fires and depositing nanodiamonds at the 'extinction boundary' marking the point in time when many species died out.
One recent impact that may have come from the comet is known as the Tagish Lake meteorite, said Professor Napier.
The object fell on Yukon Territory in Canada in January 2000. It contained the largest amount of nanodiamonds of any meteorite studied so far.
Comment: Finally, some mainstream verification of what Sott.net has been saying for years is coming through the information blackout. In February media outlets carried reports that a swarm of comet debris may have caused the 'Dark Ages' circa 500 AD. Bill Napier, as well as Victor Clube, deserve major recognition for their dedication in putting many of the puzzle pieces together. The Cycle of Cosmic Catastrophes by Firestone, West and Warwick-Smith is the seminal book on this cometary bombardment, the Younger Dryas Impact Event, at the end of the last Ice Age.
Besides older comets that break up and leave debris trails through which the Earth periodically passes, Laura Knight-Jadczyk's tireless research has led us to consider the cyclical mechanism by which comets from the Oort Cloud surrounding the outer solar system are knocked into the inner solar system by the return of the Sun's dark star companion, 'Nemesis.'
We've been observing the steady increase in the number of fireball sightings, the cooling of the upper atmosphere, strange cloud formations and recent comet impacts on other planets in our solar system. Taken with research which reveals that our environment is constantly affected by interaction with comet dust (sometimes laden with larger fragments) and cosmic radiation, we've deduced that our Big Blue Marble is once again on the threshold of encountering a cosmic storm. In fact, it's overdue for the Perfect Storm as several cycles return together.
For more in-depth reading, see Laura Knight-Jadzyck's article Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls.
Something Wicked This Way Comes, a Sott.net production: