Phil Plait: How to defend Earth from asteroids

What’s six miles wide and can end civilization in an instant? An asteroid - and there are lots of them out there. With humor and great visuals, Phil Plait enthralls the TEDxBoulder audience with all the ways asteroids can kill, and what we must do to avoid them. TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world’s leading thinkers and doers give the talk of their lives in 18 minutes. Featured speakers have included Al Gore on cli