65 million years ago, an asteroid bigger than Mount Everest slammed into the Earth wiping out the dinosaurs. Are we in for the same fate? Phil Plait investigates the possibility and tests some explosive measures that may just save our planet.
2. Alien Attack!
Phil Plait explores what it would take for a deadly alien visitation to happen on Earth.
3. Death Stars
The death of a star is one of the most violent forces in the universe capable of causing huge planetary damage.
