Carl Sagan
Born 1934 · Age 91
American astronomer, planetary scientist, and science communicator; pioneer in exobiology and SETI, author of popular science books and host of Cosmos.
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Life & Career Timeline
Born in Brooklyn, New York
Carl Edward Sagan born in the Bensonhurst neighborhood of Brooklyn to Rachel Molly Gruber and Samuel Sagan.
Visited the 1939 New York World's Fair (defining childhood moment)
At about age 4–5 Sagan attended the New York World's Fair; the exhibits (moving map, photoelectric cell, TV, time capsule) profoundly inspired his sense of wonder and later influenced his design of spaceborne time capsules.
First library visits and early curiosity about stars
Around age 5 Sagan got a library card and first learned that the Sun is a star, an experience he described as a religious-like revelation.
Discovered Astounding Science Fiction magazine
At about 13 Sagan discovered Astounding Science Fiction, which broadened his interest in hard science fiction and extraterrestrial speculation.
Family moved to Rahway, New Jersey
Sagan's family moved to Rahway, NJ, where he attended Rahway High School and continued to excel academically.
Graduated Rahway High School
Sagan graduated from Rahway High School; he was a straight-A student, president of the chemistry club, set up experiments at home and was voted 'most likely to succeed'.
Entered University of Chicago (early entrance)
Enrolled at the University of Chicago as an honors-program undergraduate under Robert M. Hutchins' early-entrance program.
Bachelor of Liberal Arts (honors) awarded
Awarded a Bachelor of Liberal Arts with general and special honors from the University of Chicago.
Bachelor of Science in Physics
Earned a B.S. in physics from the University of Chicago.
Master of Science in Physics
Received an M.S. in physics from the University of Chicago.
Married Lynn Margulis (first marriage)
Sagan married biologist Lynn Margulis; the marriage later ended in divorce (1965).
Worked on classified Project A119 (nuclear explosion on Moon plan)
Sagan collaborated with Gerard Kuiper on the U.S. Air Force's Project A119, which studied detonating a nuclear device on the Moon; he held Top Secret and NASA Secret clearances.
Ph.D. in Astronomy & Astrophysics (University of Chicago)
Earned a Ph.D.; doctoral thesis titled 'Physical Studies of the Planets' under advisor Gerard Kuiper.
Miller Fellow at UC Berkeley
From 1960–1962 Sagan was a Miller Fellow at University of California, Berkeley, conducting postdoctoral research.
Published Science article on Venus atmosphere
Published influential research on the atmosphere and high surface temperatures of Venus; worked with NASA's Mariner 2 team.
Mariner 2 confirmed Venus greenhouse hypothesis
Mariner 2 mission confirmed extremely high Venus surface temperatures consistent with Sagan's greenhouse-effect hypothesis.
Assistant professor at Harvard University
Offered and accepted an assistant professorship at Harvard; lectured, researched and advised graduate students (1963–1968), also worked at the Smithsonian Astrophysical Observatory.
Denied tenure at Harvard; moved to Cornell University
Sagan was denied academic tenure at Harvard in 1968 and accepted an offer from Cornell (cited by some as partly due to his public profile).
Joined Cornell University faculty and became director (Laboratory for Planetary Studies)
Accepted a faculty position at Cornell and became associated with the Laboratory for Planetary Studies; remained at Cornell for the rest of his life.
Promoted to full professor at Cornell
After two years as an associate professor, Sagan became a full professor (1970) and directed the Laboratory for Planetary Studies.
Mariner 9, start work on Mars missions (role advising robotic missions)
Sagan contributed to Mariner 9 and later Viking mission planning and helped select Viking landing sites; he served as an advisor to NASA and briefed Apollo astronauts.
Assembled Pioneer plaque and Pioneer 10 launched
Sagan assembled the first physical message sent into space (the Pioneer plaque). Pioneer 10 carrying the plaque launched in 1972.
Pioneer 11 launched with a copy of the plaque
Pioneer 11 was launched in 1973, also carrying a copy of the Pioneer plaque assembled by Sagan.
Klumpke-Roberts Award
Sagan received the Klumpke-Roberts Award (listed among his honors).
Arecibo message transmission
Sagan assisted Frank Drake in preparing the Arecibo message, which was beamed into space from the Arecibo radio telescope on November 16, 1974.
Named David Duncan Professor of Astronomy and Space Sciences
Sagan was appointed the David Duncan Professor of Astronomy and Space Sciences at Cornell, a position he held for life.
Published The Dragons of Eden; won Pulitzer Prize (1978)
The Dragons of Eden (speculations on evolution of human intelligence) was published and earned Sagan the Pulitzer Prize for General Nonfiction (Pulitzer awarded in 1978).
Received NASA Distinguished Public Service Medal
Sagan received NASA's Distinguished Public Service Medal (one of his NASA honors; also later awarded in 1981).
Delivered Royal Institution Christmas Lectures
Delivered the 1977 series of Royal Institution Christmas Lectures in London, a prestigious public-science lecture series.
Broca's Brain published (popular science)
Published Broca's Brain: Reflections on the Romance of Science (year approximated from context of late 1970s publications).
Cosmos: A Personal Voyage aired (TV series)
Co-wrote and narrated the 13-part PBS series Cosmos, which became the most-watched American public-television series (seen by at least 500 million people in 60 countries); accompanied by the bestselling Cosmos book.
Co-founded The Planetary Society
Co-founded The Planetary Society with Louis Friedman and Bruce Murray, a public space-advocacy organization.
Cosmos won Emmy, Peabody and other awards
The TV series Cosmos won multiple awards including at least two Emmys, a Peabody, and a Hugo Award; greatly raised Sagan's public profile.
Married Ann Druyan (third marriage)
Sagan married writer/producer Ann Druyan in 1981; they had collaborated on the Cosmos series and other projects.
Co-authored TTAPS nuclear winter paper (introduced 'nuclear winter' concept)
Sagan was one of the co-authors of the TTAPS paper modeling the climatic effects of nuclear war, which popularized the 'nuclear winter' concept and led to both influence and controversy.
Co-authored The Cold and the Dark
Co-authored the book The Cold and the Dark: The World after Nuclear War (1984) expanding on nuclear-winter consequences and disarmament arguments.
Published Contact (science-fiction novel)
Published the science-fiction novel Contact, based on a film treatment Sagan had co-written with Ann Druyan; later adapted into a 1997 film.
Oersted Medal awarded
Received the Ørsted Medal from the American Association of Physics Teachers for contributions to the teaching of physics/science.
Televised debate on Kuwaiti oil fires (Nightline) and warnings about climatic effects
During the 1991 Gulf War Sagan and colleagues warned the media that the Kuwaiti oil fires could produce 'nuclear-winter'-like effects; he debated physicist Fred Singer on ABC Nightline about the extent of the danger; Sagan later conceded he had overestimated effects.
Carl Sagan Award for Public Understanding of Science established (award bearing his name)
By this time Sagan was recognized widely; the Carl Sagan Award for Public Understanding of Science was named in his honor (he himself received multiple awards around this period).
Received National Academy of Sciences Public Welfare Medal
Awarded the Public Welfare Medal, the Academy's highest honor for distinguished contributions applying science to the public welfare.
Published Pale Blue Dot
Published Pale Blue Dot: A Vision of the Human Future in Space, a sequel to Cosmos; the book was selected as a notable book of 1995 by The New York Times.
Published The Demon-Haunted World (and popularized 'baloney detection kit')
Published The Demon-Haunted World: Science as a Candle in the Dark and popularized skeptical tools referred to as the 'baloney detection kit'.
Died of pneumonia (complication of myelodysplasia)
Sagan died in Seattle, Washington on December 20, 1996, from pneumonia related to the bone-marrow disorder myelodysplasia. He was 62.
Film adaptation of Contact released (posthumous)
The film Contact (based on Sagan's novel) premiered in 1997; Sagan did not live to see the film's release. The film later won the 1998 Hugo Award for Best Dramatic Presentation.
Cosmos remastered on DVD
The 1980 Cosmos series was released in a remastered DVD set in 2000, continuing to expand Sagan's public reach posthumously.
Dedication of the Carl Sagan Center for the Study of Life in the Cosmos
NASA Ames Research Center dedicated the Carl Sagan Center on what would have been his 67th birthday, honoring his legacy in astrobiology and public outreach.
Key Achievement Ages
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