Dr. Carl Sagan was one of the world's most famous scientists during his lifetime. He was also one of the most accomplished.
He was a professor of astronomy at Harvard University. He later taught at Cornell University between 1971 and 1996. He also served as the director of the Laboratory for Planetary Studies at Cornell.
However, he was far better known as the creator and host of the PBS television series Cosmos (1980), which was the most popular public television series of all time. An estimated 500 to 600 million people in 60 countries watched Dr. Sagan explain astronomy, biology, philosophy and the history of science in the 13-part landmark series. The companion book also became a hit, remaining on The New York Times bestseller list for 70 weeks.
Dr. Sagan wrote other books that were intended to popularize science, including The Dragons of Eden, for which he won a Pulitzer Prize. His foray into science fiction, the novel Contact, was adapted into a major motion picture starring Jodie Foster. Sadly, Dr. Sagan did not live to see the movie.
Dr. Sagan was involved with several prominent NASA projects. He helped to develop the contents of the plaques attached to the Pioneer 10 and Pioneer 11 deep-space probes. He oversaw the creation of the Voyager Golden Record launched with the Voyager space probes in 1977.
Sagan was interested in the question of whether extraterrestrial life existed. However, he did not believe that UFO sightings and alien abduction accounts were authentic.
Dr. Sagan appeared on The Tonight Show with Johnny Carson on a regular basis. Many comedians poked fun at his emphatic pronunciation of the word "billions," but he didn't mind. He even titled his last book Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium.
He explored the interaction of science and religion in his novel Contact and in Cosmos. He is generally thought to have been agnostic.
He co-authored a scientific paper and a book about the possibility of "nuclear winter" following an all-out nuclear war.
After his death, a biographer revealed that Carl Sagan had been a user of marijuana. The story received a fair amount of coverage in 1999.