National Geographic Naked Science presents "Super Volcano", the inside documentary of what might happen if the Yellowstone Caldera were to erupt one day. This documentary includes a Yellowstone timeline of past eruptions, how Yellowstone would affect the world, and what impact will it be for the U.S.

A mysterious crash in Roswell, NM during the 1940s convinced many that our planet is being visited by space aliens. Crop circles in Britain have only added fuel to the fire. Few scientists doubt that life indeed exists elsewhere, but some believe we're more likely to make contact via radio waves.