Carl Edward Sagan (November 9, 1934 - December 20, 1996) was an American astronomer. He was very interested in what life on other planets would be like, which is known as SETI (search for extraterrestrial intelligence). 

Sagan was a science communicator, which meant he taught people about science. He felt like the general public was losing interest in science, so he wrote many books and appeared on television to make it popular again. He mostly talked about planetary science and topics related to space. One of his most famous works includes. Cosmos: A Personal Voyage. Cosmos was a television series about many different scientific topics, which Sagan co-wrote and narrated. It made him very famous outside the world of science. 

Sagan supported the scientific method and scientific skepticism.

Education and work 

Carl Sagan was born in Brooklyn, New York City. Carl's family was Jewish. His father, Samuel Sagan, was an immigrant from the Russian Empire. Samuel was born in 1905 in a city called Kamianets-Podilskyi. The Russian Empire no longer exists, so today Kamianets-Podilskyi is in Ukraine. Samuel made clothes for a living. Carl's mother, Rachel Molly Gruber, was a housewife. Carl had a sister named Carol, who became a social worker. Carl was named after his grandmother, Chaiya (Clara). 

Sagan attended the University of Chicago earning two degrees in physics. He followed with a doctorate in Astronomy in 1960 and taught at Harvard University until 1968, when he moved to Cornell University.

Sagan became a teacher and director at Cornell in 1971. He helped many unmanned spacecraft to explore outer space. He thought of the idea of putting a message on spacecraft which could be understood by any life from another planet that might find it. The first message sent into space was a large gold-plated label on the space probe Pioneer 10. He continued to make the messages better. The last message he helped with was the Voyager Golden Record that was sent out with the Voyager space probes.

Scientific achievements 

He was well known as a writer who warned of the dangers of nuclear winter. He helped people learn about the atmosphere of Venus, seasonal changes on Mars, and Saturn's moon Titan. He showed that the atmosphere of Venus is very hot and dense. He also said that global warming was a growing, man-made danger like the natural development of Venus into a hot and dangerous planet with greenhouse gases. He suggested that the seasonal changes on Mars were due to dust storms.

Sagan was among the first to guess that Titan and Jupiter's moon Europa might have oceans or lakes, which means that life could be there. Europa's underground ocean was later confirmed by the spacecraft Galileo.

Sagan thought the search for life on other planets was a good idea. He said scientists should listen with large radio telescopes for signals from other planets. He thought sending probes to other planets was a good idea. Sagan was editor Icarus (a magazine about space exploration) for 12 years. He helped start the Planetary Society and was a member of the SETI Institute Board of Trustees.

Social concerns 

Sagan also believed that the Drake equation suggested that many kinds of intelligent life could form, but that the lack of evidence (the Fermi paradox) suggests that intelligent beings destroy themselves rather quickly. This made him keen to talk about ways that humanity could destroy itself, in the hope of avoiding such destruction.

Under the name "Mr. X," Sagan wrote about pot smoking in the 1971 book Reconsidering Marijuana. Lester Grinspoon (the book's editor), told this to Keay Davidson, Sagan's biographer. Sagan said that marijuana helped him write some of his books.

Making science popular 

Sagan was very good at helping people to understand the cosmos. He gave the 1977/1978 Christmas Lectures for Young People at the Royal Institution. He wrote (with Ann Druyan, who became his third wife) and made the very popular thirteen-part PBS television series Cosmos; he also wrote books to help science become more popular (The Dragons of Eden, which won a Pulitzer Prize, Broca's Brain, etc.) and a novel, Contact, that was a best-seller and was made into a film starring Jodie Foster in 1997. The film won the 1998 Hugo Award.

After Cosmos, Sagan was linked with the catchphrase "billions and billions", which he never used in the television series (but he often used the word "billions"). He wrote Pale Blue Dot: A Vision of the Human Future in Space, which was chosen as a notable book of 1995 by The New York Times.

Not all scientists agreed with him. Although they all liked the way he made science popular, some were afraid that people would think that his personal opinions might be confused with real science. What he said about the Kuwait oil well fires during the first Gulf War were shown later to be wrong.

Later in his life, Sagan's books showed his skeptical, naturalistic view of the world. In his book The Demon-Haunted World, Sagan gave a list of mistakes he had made as an example of how science is self-correcting. The compilation Billions and Billions: Thoughts on Life and Death at the End of the Millennium, published after Sagan's death, contains essays written by Sagan, such as his views on abortion, and Ann Druyan's account of his death as a non-believer.

Legacy 

After a long and difficult fight with myelodysplasia, Sagan died of pneumonia at the age of 62, on December 20, 1996, at the Fred Hutchinson Cancer Research Center in Seattle, Washington. Sagan was very important, because he made science popular, and changed the way science was organized, and because he defended humanism, and argued against seeing things from only one point of view.

The landing site of the unmanned Mars Pathfinder spacecraft was renamed the Carl Sagan Memorial Station in honor of Dr. Sagan on July 5, 1997. Asteroid 2709 Sagan is also named in his honor.

The 1997 movie Contact (see above), based on Sagan's novel of the same name, and finished after his death, ends with the dedication "For Carl."

Awards and medals 

 Apollo Achievement Award - National Aeronautics and Space Administration
 Chicken Little Honorable Mention - 1991 - National Anxiety Center
 Distinguished Public Service - National Aeronautics and Space Administration
 Emmy - Outstanding individual achievement - 1981 - PBS series Cosmos
 Emmy - Outstanding Informational Series - 1981 - PBS series Cosmos
 Exceptional Scientific Achievement Medal - National Aeronautics and Space Administration
 Helen Caldicott Leadership Award - Women's Action for Nuclear Disarmament
 Homer Award - 1997 - Contact
 Hugo Award - 1998 - Contact
 Hugo Award - 1981 - Cosmos
 Hugo Award - 1997 - The Demon-Haunted World
 In Praise of Reason Award - 1987 - Committee for the Scientific Investigation of Claims of the Paranormal
 Isaac Asimov Award - 1994 - Committee for the Scientific Investigation of Claims of the Paranormal
 John F. Kennedy Astronautics Award - American Astronautical Society
 John W. Campbell Memorial Award - 1974 - The Cosmic Connection
 Konstantin Tsiolkovsky Medal - Soviet Cosmonauts Federation
 Locus Poll Award 1986 - Contact
 Lowell Thomas Award - Explorers Club - 75th Anniversary
 Masursky Award - American Astronomical Society
 Peabody - 1980 - PBS series Cosmos
 Public Welfare Medal - 1994 - National Academy of Sciences
 Pulitzer Prize for Literature - 1978 - The Dragons of Eden
 SF Chronicle Award - 1998 - Contact
 Carl Sagan Memorial Award - Named in his honor

Related books and media 

 Sagan, Carl and Jonathon Norton Leonard and editors of Life, Planets. Time, Inc., 1966
 Sagan, Carl and I.S. Shklovskii, Intelligent Life in the Universe. Random House, 1966
 Sagan, Carl, Communicaton with Extraterrestrial Intelligence. MIT Press, 1973
 Sagan, Carl, et al. Mars and the Mind of Man. Harper & Row, 1973
 Sagan, Carl, Other Worlds. Bantam Books, 1975
 Sagan, Carl, et al. Murmurs of Earth: The Voyager Interstellar Record. Random House, 1977
 Sagan, Carl et al. The Nuclear Winter: The World After Nuclear War. Sidgwick & Jackson, 1985
 Sagan, Carl and James Randi, The Faith Healers. Prometheus Books, May 1989, , 318 pgs
 Sagan, Carl and Richard Turco, A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race. Random House, 1990
 Sagan, Carl, The Dragons of Eden: Speculations on the Evolution of Human Intelligence. Ballantine Books, December 1989, , 288 pgs
 Sagan, Carl, Broca's Brain: Reflections on the Romance of Science. Ballantine Books, October 1993, , 416 pgs
 Sagan, Carl and Ann Druyan, Shadows of Forgotten Ancestors: A Search for Who We Are. Ballantine Books, October 1993, , 528 pgs
 Sagan, Carl and Ann Druyan, Comet. Ballantine Books, February 1997, , 496 pgs
 Sagan, Carl, Contact. Doubleday Books, August 1997, , 352 pgs
 Sagan, Carl, Pale Blue Dot: A Vision of the Human Future in Space. Ballantine Books, September 1997, , 384 pgs
 Sagan, Carl and Ann Druyan, Billions & Billions: Thoughts on Life and Death at the Brink of the Millennium. Ballantine Books, June 1998, , 320 pgs
 Sagan, Carl, The Demon-Haunted World: Science As a Candle in the Dark. Ballantine Books, March 1997, , 480 pgs
 Sagan, Carl and Jerome Agel, Cosmic Connection: An Extraterrestrial Perspective. Cambridge University Press, January 15, 2000, , 301 pgs
 Sagan, Carl, Cosmos. Random House, May 7, 2002, , 384 pgs
 Zemeckis, Robert, Contact. Warner Studios, 1997, ASIN 0790736330 IMDB 
 Davidson, Keay, Carl Sagan: A Life. John Wiley & Sons, August 31, 2000, , 560 pgs

Other websites 

 In Memory of Carl Sagan. Tributes by Tom McDonough, James Randi and Michael Shermer, and a selection of quotes from Sagan's works, published in Skeptic, Vol. 4, no. 4, 1996, pp. 10–17.
 CarlSagan.Com. Homepage of Cosmos Studios, which sells the Cosmos series on DVD and VHS video tape.
 Carl Sagan, Cornell astronomer, dies today (Dec. 20) in Seattle. Cornell University press release on Sagan's death.
 Even in Death, Carl Sagan's Influence Is Still Cosmic by William J. Broad, The New York Times, November 30, 1998. Describes Sagan's legacy for space science.
 Astronomy Picture of the Day: Carl Sagan. December 26, 1996.
 Contact: A Eulogy to Carl Sagan, by Dr. Ray Bohlin, president of Probe Ministries. Dr. Bohlin suggests that the movie Contact can serve as a fitting eulogy for Carl Sagan. Sagan's scientific approach to the question, "was the universe created?" is critically analyzed by Bohlin from his Christian perspective.

References

1934 births
1996 deaths
Agnostics
American astronomers
Deaths from pneumonia
Infectious disease deaths in the United States
Jewish American scientists
Jewish American writers
Pulitzer Prize winners
Scientists from New York
Writers from New York City
Emmy Award winners