The Last Extinction

NOVA: In May 2008, a scientific team made worldwide headlines by announcing that a previously unsuspected impact from space had devastated prehistoric North America at the end of the last ice age. According to this controversial new claim, the extinction of more than 34 types of big prehistoric animals was caused not by climate change or the arrival of the first human hunters, but by the massive break-up of a comet over the Great Lakes region. This documentary explores the provocative theory.