Astronomers have contributed greatly to our understanding of physics and motion. In this section you can learn all about famous astronomers and what each of them has contributed to our understanding of space.
He is famous for a phrase he never said, for wearing turtlenecks and for hosting the original 'Cosmos' TV series. As enthusiastic about the stars as he was about marijuana, Carl Sagan led a very surprising life. Here are 10 cool facts. See more »