Asteroid impacts! Cometary debris! Extinction level events! These are the topics covered in this scientifically-based but fun look at giant impacts from cosmic objects. Phil Plait talks about how these events have shaped our history, how they may do so again, and why Hollywood always seems to get them wrong. And lest you think it’s all doom and gloom, Plait goes into details on how we might prevent the next great impact from ruining our whole day.