Carl Sagan

Carl Edward Sagan (9 November 1934 – 20 December 1996) was an American astronomer, cosmologist, author, and science communicator. He co-wrote and hosted the original series of Cosmos, archive footage of which appeared in the later series. He also wrote the accompanying book and its sequel, and his picture graces the back of the show's soundtrack album.

Career Highlights
His best-known scientific contribution is research on the possibility of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation. Sagan assembled the first physical messages sent into space: the Pioneer plaque and the Voyager Golden Record, universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. Sagan argued the now-accepted hypothesis that the high surface temperatures of Venus can be attributed to and calculated using the greenhouse effect.

Initially an associate professor at Harvard and later at Cornell from 1976 to his death, he was the David Duncan Professor of Astronomy and Space Sciences at the latter. Sagan published more than six hundred scientific papers and articles and was author, co-author, or editor of more than twenty books. He wrote many popular science books, such as The Dragons of Eden, Broca's Brain, and Pale Blue Dot, and narrated and co-wrote the award-winning 1980 television series Cosmos A Personal Voyage. The most widely watched series in the history of American public television, Cosmos has been seen by at least five hundred million people across sixty different countries. The book Cosmos was published to accompany the series. He also wrote the science fiction novel Contact, the basis for a 1997 film of the same name. His papers, containing 595,000 items, are archived at The Library of Congress.

Sagan advocated scientific skeptical inquiry and the scientific method, pioneered exobiology and promoted the Search for Extra-Terrestrial Intelligence (SETI). He spent most of his career as a professor of astronomy at Cornell University, where he directed the Laboratory for Planetary Studies. Sagan and his works received numerous awards and honors, including the NASA Distinguished Public Service Medal, the National Academy of Sciences Public Welfare Medal, the Pulitzer Prize for General Non-Fiction for his book The Dragons of Eden, and, regarding Cosmos: A Personal Voyage, two Emmy Awards, the Peabody Award, and the Hugo Award.

Personal Life
Carl Sagan married three times and had five children. In 1957, he married biologist Lynn Margulis. The couple had two children, Jeremy and Dorion Sagan. After he and Margulis divorced, he married artist Linda Salzman in 1968 and they also had a child together, Nick Sagan. During these marriages, Carl Sagan focused heavily on his career, a factor which may have contributed to Sagan's first divorce. After co-writing Cosmos with author Ann Druyan, Sagan married her in 1981, and they later had two children, Alexandra, known as Sasha, and Samuel Sagan. After suffering from myelodysplasia, Sagan died of pneumonia at the age of 62.