Astrophysicist Neil deGrasse Tyson explores whether life is unique to Earth. "The elements essential to life as we know it are widespread throughout the universe," Tyson says, but no extraterrestrial life has yet been found. Why?
This program reviews the Drake equation to provide an updated estimate of the likelihood that there is another civilization close enough to Earth for us to talk with. And it ponders the question; with so many strange life forms on earth how would we know an alien if we met one?—David Foss