Carl Sagan (1934-1996) was an American planetary astronomer known for his strong support of the systematic, scientific search for extraterrestrial life and his popular books and television programmes about science.
Sagan worked for many years on NASA's planetary exploration programmes including Voyager and Viking. He correctly predicted that Venus is heated by the greenhouse effect and that observed changes in Mars's surface features are caused by dust storms, not changes in seasonal vegetation.
Image: Carl Sagan poses with a model of the Viking lander in Death Valley, California (credit: NASA/JPL)
Prior to Mariner 2's 1962 flyby of Venus, some scientists such as Dr Carl Sagan thought that conditions on the planet might favour life. However, the probe's instruments showed that the cloudy planet's surface was extremely hot, greatly reducing the chance that anything could survive there.
Earth is a tiny blue dot when viewed from the edge of the Solar System.
In 1990, 13 years after leaving the Earth and at a distance of 3.7 billion miles, Voyager 1 turned around to face the Sun and captured images of most of the planets, including the Earth. Voyager scientist Carl Sagan described our planet as a "blue dot".
Sir Patrick Moore spoke to Dr Carl Sagan in 1974 about the search for other civilisations.
Carl Edward Sagan ( /ˈseɪɡɪn/; November 9, 1934 – December 20, 1996) was an American astronomer, astrophysicist, cosmologist, author, science popularizer, and science communicator in astronomy and natural sciences. He published more than 600 scientific papers and articles and was author, co-author or editor of more than 20 books. He advocated scientifically skeptical inquiry and the scientific method, pioneered exobiology and promoted the Search for Extra-Terrestrial Intelligence (SETI).
Sagan is known for his popular science books and for the award-winning 1980 television series Cosmos: A Personal Voyage, which he narrated and co-wrote. The book Cosmos was published to accompany the series. Sagan wrote the novel Contact, the basis for a 1997 film of the same name.
This entry is from Wikipedia, the user-contributed encyclopedia. If you find the content in the 'About' section factually incorrect, defamatory or highly offensive you can edit this article at Wikipedia.
BBC © 2012 The BBC is not responsible for the content of external sites. Read more.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.
