Astronomer, educator and author, Sagan was perhaps the world's greatest popularizer of science, reaching millions of people through newspapers, magazines and television broadcasts. He is well-known for his work on the PBS series Cosmos, the Emmy- and Peabody-award-winning show that became the most watched series in public-television history. It was seen by more than 500 million people in 60 countries. The accompanying book, Cosmos (1980), was on The New York Times bestseller list for 70 weeks and was the best-selling science book ever published in English. Carl Edward Sagan was born Nov. 9, 1934, in Brooklyn, N.Y. Having taught at Cornell since 1968, Sagan received a bachelor's degree in 1955 and a master's degree in 1956, both in physics, and a doctorate in astronomy and astrophysics in 1960, all from the University of Chicago. He taught at Harvard University in the early 1960s before coming to Cornell, where he became a full professor in 1971. Sagan played a leading role in NASA's Mariner, Viking, Voyager and Galileo expeditions to other planets. He received NASA Medals for Exceptional Scientific Achievement and twice for Distinguished Public Service and the NASA Apollo Achievement Award. His research focused on topics such as the greenhouse effect on Venus; windblown dust as an explanation for the seasonal changes on Mars; organic aerosols on Titan, Saturn's moon; the long-term environmental consequences of nuclear war; and the origin of life on Earth. A pioneer in the field of exobiology, he continued to teach graduate and undergraduate students in courses in astronomy and space sciences and in critical thinking at Cornell. The breadth of his interests were made evident in October 1994, at a Cornell-sponsored symposium in honor of Sagan's 60th birthday. The two-day event featured speakers in areas of planetary exploration, life in the cosmos, science education, public policy and government regulation of science and the environment -- all fields in which Sagan had worked or had a strong interest. Sagan was the recipient of numerous awards in addition to his NASA recognition. He received 22 honorary degrees from American colleges and universities for his contributions to science, literature, education and the preservation of the environment and many awards for his work on the long-term consequences of nuclear war and reversing the nuclear arms race. Among his other awards were: the John F. Kennedy Astronautics Award of the American Astronautical Society; the Explorers Club 75th Anniversary Award; the Konstantin Tsiolkovsky Medal of the Soviet Cosmonauts Federation and the Masursky Award of the American Astronomical Society. He also was the recipient of the Public Welfare Medal, the highest award of the National Academy of Sciences, "for distinguished contributions in the application of science to the public welfare." Sagan was elected chairman of the Division of Planetary Sciences of the American Astronomical Society, president of the Planetology Section of the American Geophysical Union and chairman of the Astronomy Section of the American Association for the Advancement of Science. For 12 years he was editor of Icarus, the leading professional journal devoted to planetary research. He is co-founder of The Planetary Society, a 100,000-member organization and the largest space-interest group in the world. The society supports major research programs in the radio search for extraterrestrial intelligence, the investigation of near-Earth asteroids and, with the French and Russian space agencies, the development and testing of balloon and mobile robotic exploration of Mars. Sagan also was Distinguished Visiting Scientist at the Jet Propulsion Laboratory in California and was contributing editor of Parade magazine, where he published many articles about science and about the disease that he battled for the last two years of his life.
