On November 9, 1934, American astronomer, astrophysicist, cosmologist, and successful author Carl Sagan was born. Carl 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.
Carl Sagan grew up in Brooklyn, New York and received his education in mainly public schools. Even though his parents were no scientists, they have influenced his later career dramatically. Taking him to the 1939 World’s Fair was one of these events that made Sagan become curious and ambitious. He began studying by himself at the public library at the age of five, wanting to learn the exact definition of stars. It troubled him, that no adult or friend could give him a good answer and he found out that “the answer was stunning. It was that the Sun was a star but really close. The stars were suns, but so far away they were just little points of light … The scale of the universe suddenly opened up to me. It was a kind of religious experience. There was a magnificence to it, a grandeur, a scale which has never left me“. Carl Sagan enrolled at the University of Chicago, where he received his Ph.D. in 1960. About two years later, he began working at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts. Later on, he moved to Ithaca, New York to become a professor at Cornell University.
Next to his teaching career, Sagan worked as an advisor to NASA. One of his tasks there was to instruct the Apollo astronauts before flying to the moon. When contributing to the robotic spacecraft missions, Sagan got the idea to add a message on spacecraft destined to leave the Solar System that could potentially be understood by any extraterrestrial intelligence that might find it. The first message was attached to space probe Pioneer 10, launched in 1972. Another was attached to Voyager in 1977.
In the 1960’s, it was not clear what the basic conditions on planet Venus were. Carl Sagan made significant contributions to discovering the surface’s temperature. Also he assumed that Venus was very dry and hot as he investigated radio emissions from the planet. Mariner 2 later confirmed these conclusions. Furtherly, Sagan was one of the first scientists to assume that Jupiter’s moon Europa might possess subsurface oceans of water, which would make the moon possibly habitable and was confirmed by spacecraft Galileo. Sagan did further work on the conditions of the planets in our solar system, but to his fields of highest interests belonged research on the possibilities of extraterrestrial life.
Along with Ann Druyan, Sagan produced and wrote the tv-series ‘Cosmos’, which covered widely ranged scientific subjects like the origins of human life and mankind’s place in the universe. The series became very popular and was broadcasted in over 60 counties. But all of those activities did not keep him from searching for extraterrestrial life and he set up a community that listened with radio telescopes for signals from potential intelligent extraterrestrial life-forms. Sagan was able to increase the respectability to this quite controversial field of research.
At yovisto, you may enjoy a short video lecture by Carl Sagan himself, explaining the 4th Dimension.
References and Further Reading:
- Carl Sagan Website
- A man whose time has come—Interview with Carl Sagan, New Scientist, July 4, 1974
- Carl Sagan’s Life and Legacy as Scientist, Teacher, and Skeptic
Relates Articles in the Blog:
- All articles at yovisto Blog related to astrophysics
- Subrahmanyan Chandrasekhar and the Evolution of Stars
- Jocelyn Bell Burnell and the Discovery of Pulsars
- Nathan Rosen on Wormholes and a Thought Experiment
- George Lemaître and the Big Bang Theory
- Fred Hoyle and the Big Bang Theory