(1934-1996) American Astronomer, Planetary Scientist
Carl Sagan is among the best-known scientists of the 20th century. He was trained as an astronomer and performed much outstanding research in astronomy. However, relatively early in his career, he turned his efforts to planetary science and contributed greatly in that regard as well. His first planetary research was to study the greenhouse effect on Venus. He showed that the thick caustic clouds that engulf the planet prevented solar radiation from escaping and predicted excessive surface temperatures that were later confirmed by space probes. He studied the atmosphere on Mars, predicting it to be a desert and explaining observed seasonal changes to be a result of windblown dust storms. He completed studies of Saturn’s moon Titan, on which he identified organic aerosols in the atmosphere. Because of his expertise on planets and planetary evolution, Sagan was invited to participate on NASA’s Apollo missions. He was also one of the leaders in each of the teams for the unmanned Mariner, Viking, Voyager, and Galileo missions to other planets of the solar system.
Carl Sagan later became interested in the origin of life on Earth. He studied the conditions and constraints on how life started but also how it evolved. With his background in these constraints coupled with knowledge of planetary evolution, he helped pioneer a new field of “exobiology” which predicts the form of extraterrestrial life under a typical scenario of development. Sagan was also very interested in mass extinctions, especially involving extraterrestrial impacts. He used the interpreted effects of such impacts to warn against nuclear proliferation to the public as well as in hearings before the U.S. Congress. He asked if such a “nuclear winter” could wipe out the dinosaurs, what could it do to humans?
No description of Carl Sagan would be complete without mentioning his work on popularizing science. Sagan has been called the “world’s greatest popularizer of science.” His book, Cosmos, which accompanied the Emmy Award- and Peabody Award-winning Public Broadcasting Station series, was the best-selling science book ever published in English. It was on the New York Times best-seller list for 70 weeks. He has had seven other books on that list. His book, The Dragons of Eden, won him a Pulitzer Prize. His novel, Contact, was made into a 1997 Warner Brothers movie which Sagan and his wife were coproducing at the time of his death. All of his books are vehicles to share his scientific knowledge with the public. Carl Sagan is a true giant of science.
Carl Edward Sagan was born on November 9, 1934, in Brooklyn, New York. He attended the University of Chicago, Illinois, where he earned a bachelor of arts degree with honors in 1954, a bachelor of science degree in 1955, and a master of science degree in 1956, all of which were in physics. His doctoral degree was in astronomy and astrophysics, which he received in 1960, also from the University of Chicago. He was a Miller Research Fellow at the University of California at Berkeley from 1960 to 1962 before joining the faculty at Harvard University, Massachusetts. In 1968, he moved to Cornell University, New York, where he was director of the Laboratory for Planetary Studies, in addition to his faculty position. Sagan also served as associate director of the Center for Radio Physics and Space Research from 1972 to 1981. In 1976, he was named a David Duncan Professor of Astronomy. He was also president of Carl Sagan Productions beginning in 1977. Carl Sagan’s last marriage was to Ann Druyan, who collaborated with him on many of his projects. He was father to five children from previous marriages. Carl Sagan was diagnosed with mylodysplasia, a bone marrow cancer, in 1994 and died of pneumonia resulting from it on December 20, 1996, in Seattle, Washington. His remains were released in space on a subsequent space shuttle mission.
There are not many more productive careers than that led by Carl Sagan. He is an author of more than 600 scientific papers and popular articles in a variety of technical and nontechnical publications. He is also an author or editor of some 20 books and professional volumes. The honors and awards that Sagan received for his contributions both to science and bringing science to the public are equally astounding and too numerous to list here completely. He was a member of the National Academy of Sciences and the American Academy of Arts and Sciences. He received some 22 honorary degrees from American colleges and universities including such schools as Rensselaer Polytechnic Institute, Whittier College, and the University of Wyoming, among others. He was the recipient of the Public Welfare Medal, the highest award from the National Academy of Sciences. NASA awarded him the Medal for Exceptional Scientific Achievement, the Apollo Achievement Award, and two Distinguished Public Service Awards. He also received the John F. Kennedy Award and the Masursky Award from the American Astronautical Society, the Kon-stantin Tsiolkovsky Medal of the Soviet Cosmonauts Federation, the Smith Prize from Harvard University, and the Explorers Club 75th Anniversary Award, among at least eight others both scientific and literary. He was named to more than 20 prestigious honorary lectureships at numerous universities and societies.
Sagan was also a great contributor of his time to professional service. He was a cofounder of the Planetary Society, which now boasts more than 100,000 members. He was president of the plane-tology section of the American Geophysical Union, and chair of the Division of Planetary Sciences of the American Astronomical Society, and the chair of the astronomy section of the American Association for the Advancement of Science, among numerous other committees for these organizations, as well as NASA, National Academy of Sciences, the National Research Council, and the International Society for the Origin of Life, among others. He was also a member of the U.S. Committee for East-West Accord. Sagan served as editor of the planetary journal Icarus for more than 12 years.
