Philippe Cousteau explores Yellowstone National Park, the site of a potential super-volcano. Fifty miles of magma lurks near the surface, and if it were to erupt, its ash would cover the earth and damage crops worldwide as well as our drinking water. Then Philippe visits Meteor Crater in Arizona, the site where a meteor once struck 50,000 years ago. We’ll examine the damage it caused, and wonder if it could happen again. Then we travel to the Hawaiian Island of Maui, where powerful telescopes search the universe for meteors that might be heading our way. We explore the possibility of another meteor reaching our planet.