We’ve found lots of “habitable” worlds but we don’t know what factors are needed for life. There are lots of reasons to search for planets around other stars—exoplanets. A big one is to find other ...

Tiny dust particles collected from a comet and brought to earth last year now have scientists rethinking some of their beliefs about how comets--and the rest of our solar system--originally formed.

Explore a massive collection of thought-provoking documentaries, including exclusive films from Ken Burns. Sometimes I like taking a break from all my scripted shows to watch something a little ...