There have been at least five destructive extinction events in the geological history of the Earth, nearly all the result of gigantic rocks, called asteroids, impacting the Earth. What are asteroids? Where did they come from? Are there more out there? Is the Moon a captured asteroid? When is the next huge impact? Do asteroids impact other planets? Did they play a role in starting life on Earth (and possibly Mars)? UW Astronomer Bruce Balick returns to address these questions and describe more wonders of our solar system.