Some scientists hypothesize that relatively recently in our geological history a comet collided with Earth. And they’re not talking about the collision 65 million years ago that did in the dinosaurs. They’re talking about a collision 12,900 years ago, which did away with woolly mammoths, saber-tooth tigers and giant sloths, among some three dozen large mammals. Full story:
* The New York Times - The Sky is Falling;
* MSNBC: Comet impacts can destroy stellar systems:
