Ancient Rocks of Doom!

If the Peruvian zombie plague meteorite isn't bad enough, now it seems a Giant Rock From Space may have killed off the mammoths.  Ted Bunch, a Northern Arizona University researcher, thinks the mass extinction at the end of the Ice Age 13,000 years ago may have been the result of a large comet exploding in the Earth's atmosphere.  Bunch and his bunch have found a layer of carbon-rich material distributed throughout the Northern Hemisphere which includes fullerene molecules and tiny diamonds characteristic of impact events.  But there's no big recent crater showing where the thing hit.  Their theory is that an icy comet nucleus entered the Earth's atmosphere and exploded, in a kind of super-Tunguska event.  The blast was powerful enough to cause mass extinctions across the globe.

If true (and that's still a pretty big if) this theory pokes a hole in the long-held belief that humans were the cause of the Pleistocene extinction -- that all those mammoths, New World horses and camels, giant ground sloths, etc. were killed off by early humans with spears and bows.  As I've mentioned before, that always smacked of a secular version of Original Sin.

Meanwhile, those of us concerned about Giant Rocks From Space can use a new version of Larry Niven's slogan:  "The dinosaurs and the wooly mammoths died out because they didn't have a space program."

A tip of the steel anti-meteorite helmet to Rand Simberg at Transterrestrial Musings for spotting this.