Recent hits

Exploding asteroid theory strengthened by new evidence located in Ohio, Indiana

So, maybe an asteroid hit Canada about 13,000 years ago, causing a wee bit of upset to the climate in the process. Interesting theory.

On a similar topic, to commemorate its100 year anniversary, Australia's Duncan Steel wrote an article at Nature about the various theories that have been offered over the years regarding the Tunguska event. Unfortunately, it's behind a paywall, but Jerry Pournelle's email page seems to have copied it all out. Good reading.