Sagan, Carl Edward
Sagan, Carl Edward
(sā`gən), 1934–96, American astronomer and popularizer of science, b. New York City. Early in his career he investigated radio emissions from Venus and concluded that the cause was a surface temperature of c.900°F; (500°C;) and crushing atmospheric pressure. He also studied color variations on Mars' surface, concluding that they were not seasonal changes as most believed but shifts in surface dust caused by windstorms. Both conclusions were substantially confirmed years later by space probes. Sagan is best known, however, for his research on the possibilities of extraterrestrial life (see exobiologyexobiologyor astrobiology,
search for extraterrestrial life within the solar system and throughout the universe. Philosophical speculation that there might be other worlds similar to ours dates back to the ancient Chinese and Greeks.
..... Click the link for more information. ), including experimental demonstration of the production of amino acids from basic chemicals by radiation. A professor of astronomy and space sciences at Cornell after 1968, he was involved with numerous NASA planetary space probes and was the creator and host of the 1980 public television science series Cosmos. His publications include The Dragons of Eden (1977; Pulitzer Prize); a novel, Contact (1985); with Richard Turco, A Path Where No Man Thought (1990), on nuclear winternuclear winter,
theory holding that the smoke and dust produced by a large nuclear war would result in a prolonged period of cold on the earth. The earliest version of the theory, which was put forward in the early 1980s in the so-called TTAPS report (named for last initials of
..... Click the link for more information. ; with Ann Druyan, Shadows of Forgotten Ancestors (1992); Pale Blue Dot (1994); and The Demon-Haunted World (1995).
Bibliography
See biographies by K. Davidson (1999) and W. Poundstone (1999).