There's a lot of tribute videos of Carl Sagan on the web.  This one deals with the famous picture called ...

The Pale Blue Dot is a photograph of planet Earth taken in 1990 by Voyager 1 from a record distance, showing it against the vastness of space. By request of Carl Sagan, NASA commanded the Voyager 1 spacecraft, having completed its primary mission and now leaving the solar system, to turn its camera around and to take a photograph of Earth. It was subsequently used by Sagan as the title of his 1994 book of the same name.