The American astronomer and popularizer of science Carl E. Sagan (1934-1996) studied the surfaces and atmospheres of the major planets, conducted experiments on the origins of life on earth, made important contributions to the debate over the environmental consequences of nuclear war, and wrote a number of popular books explaining developments in astronomy, biology, and psychology.

Carl Edward Sagan was born November 9, 1934, in New York City. Pursuing a boyhood fascination with the stars, he studied astronomy at the University of Chicago, receiving his undergraduate degree in 1954 and his doctorate in 1960. After holding teaching and/or research posts at the University of California-Berkeley, Harvard University, the Smithsonian Astrophysical Observatory, and Stanford University, Sagan became director of Cornell University's Laboratory for Planetary Studies and David Duncan Professor of Astronomy and Space Science (1970). In addition to his academic appointments Sagan served as a consultant to the National Aeronautics and Space Administration...