Episode 2 in one of the great educational series of all time by the late Carl Sagan. In this episode Carl Sagan explores the search for who we are by looking at life, through the Cambrian explosion, through natural selection on earth and suggesting theories about what life may be like on other planets if there is any at all.
Back in 1980 we did not know if there were really any other planets outside our solar system. Now thanks to NASA missions such a Kepler we know for a fact that there are millions in not billions of planets out there. As Kepler observes thousands of plants every day we are discovering many things such as what their atmospheres are comprised of and whether or not they could support life.