A Meteoric View of Life
Published: December 4, 2003
That extinction is dwarfed by the one that took place 251 million years ago, an event some scientists call the "great dying." As much as 90 percent of the life on earth may have disappeared. Scientists studying new evidence, including meteorite fragments from Antarctica, now argue that the extinction then — the greatest of them all — was probably caused by a meteor impact as well.
The explosion would have been colossal enough, but it also sparked increased volcanism around the globe, compounding the dire climatic changes that were caused by the airborne debris from the collision itself.
Every day many meteors, most of them tiny, reach the earth's atmosphere. It's a condition of the astronomical neighborhood we live in. But it is hard to take in the fact that catastrophic meteor impacts have played such an enormous part in the history of life on this planet.
Download Yahoo! Messenger now for a chance to WIN Robbie Williams "Live At Knebworth DVD"