Dr. Carl Sagan
- Born: Nov 09, 1934 in New York City, New York
- Died: Dec 20, 1996 in Seattle, Washington
- Occupation: Actor
- Active: '80s-'90s
- Major Genres: Science & Technology
- Career Highlights: Contact
- First Major Screen Credit: Contact (1997)
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[b. New York City, November 9, 1934, d. Seattle, Washington, December 20, 1996]
Sagan promoted planetary astronomy and the search for intelligent life, becoming one of America's best-known scientists through television and popular books. He explained the runaway greenhouse effect on Venus and contributed to the theory that dust from large explosions, such as asteroid impacts, causes mass extinctions by lowering temperatures and stopping photosynthesis over all of Earth.
The American astronomer and popularizer of science Carl E. Sagan (1934-1996) studied the surfaces and atmospheres of the major planets, conducted experiments on the origins of life on earth, made important contributions to the debate over the environmental consequences of nuclear war, and wrote a number of popular books explaining developments in astronomy, biology, and psychology.
Carl Edward Sagan was born November 9, 1934, in New York City. Pursuing a boyhood fascination with the stars, he studied astronomy at the University of Chicago, receiving his undergraduate degree in 1954 and his doctorate in 1960. After holding teaching and/or research posts at the University of California-Berkeley, Harvard University, the Smithsonian Astrophysical Observatory, and Stanford University, Sagan became director of Cornell University's Laboratory for Planetary Studies and David Duncan Professor of Astronomy and Space Science (1970). In addition to his academic appointments Sagan served as a consultant to the National Aeronautics and Space Administration (NASA) and was closely associated with the unmanned space missions to Venus, Mars, Jupiter, and Saturn. Sagan's work in the popularization of science, which brought him public recognition as author, lecturer, and television personality, won for him the Pulitzer Prize in 1978.
Carl Sagan's main contributions to science were made in the fields of planetary studies and the origin of life. His first major research effort was an investigation of the surface and atmosphere of Venus. In the late 1950s the prevailing scientific view was that the surface of Venus was relatively cool, life of some sort might exist on the planet, and the observed Venusian radio emissions had their origins in the activity of charged particles located in an atmospheric layer. Sagan (1961) overturned this by showing that the emissions could be explained by simply assuming that the Venusian surface was very hot, over 300 degrees Centigrade, and therefore hostile to life. He accounted for the high temperatures by positing the existence of a "greenhouse effect" that resulted from the sun's heat being trapped between the Venusian surface and the planet's carbon dioxide cloud cover. This hypothesis was confirmed by an exploratory space vehicle sent to Venus by the Soviet Union in 1967.
Solar System Research
The physical characteristics of the surface of Mars have long interested astronomers and science fiction writers. Telescopic observation of the planet revealed distinctive bright and dark areas on its surface. This led some to speculate that large regions of Mars were covered with vegetation subject to seasonal changes. So matters stood until the mid-20th century, when radar and other new means of surveillance were used to gather information on the topography, temperature, wind velocities, and atmosphere of Mars. Reviewing this newly collected data, Sagan concluded that the bright regions were lowlands filled with sand and dust blown by the wind and that the dark areas were elevated ridges or highlands. Hence there was no need to assume the existence of extensive Martian plant growth.
Sagan's scientific interest in planetary surfaces and atmospheres led him to investigate the origins of life on earth and to champion the study of exobiology (the biology of extraterrestrial life). In the mid-1950s Harold Urey and Stanley Miller successfully produced key organic compounds in the laboratory by simulating the physical and chemical conditions that prevailed upon earth shortly before the first forms of life appeared. Building upon this research, Sagan irradiated a mixture of methane, ammonia, water, and hydrogen sulfide. In these experiments he was able to produce amino acids and adenosine triphosphate (ATP), complex chemical compounds which are crucial to living cells. Sagan's foray into biochemistry contributed to a better understanding of the nature and origins of terrestrial life and testified to his competence in fields of science beyond astronomy.
Popular Writing
It is not his scientific achievements but his popular books and his television appearances that have made Sagan a well-known public figure. In 1973 he published The Cosmic Connection, a lively introduction to space exploration and the search for extraterrestrial life. Four years later there appeared his Pulitzer Prize winning book on the evolution of human intelligence, The Dragons of Eden. Drawing upon recent work in neuro-physiology and exploring the brain-computer analogy and studies of sleep and dreaming, as well as interpretations of mythology, Sagan created a highly readable, original, and witty account of the development of the human intellect. Another of Sagan's books, Cosmos (1980), deserves notice because it was written in conjunction with his well-received television series of the same name. In this work Sagan offered a summary history of the physical universe, showed how the cosmos came to be understood with the help of modern science, and warned that the earth was in danger of being destroyed by a nuclear holocaust.
In December of 1983 Sagan, with colleagues R. P. Turco, O. B. Toon, T. P. Ackerman, and J. B. Pollack, published "Nuclear Winter: Global Consequences of Multiple Nuclear Explosions," an article which transformed the world-wide public debate over nuclear policy. The authors claimed that in a nuclear war tremendous quantities of soot and dust would be injected into the atmosphere to form a gigantic black cloud covering most of the Northern Hemisphere. This cloud would reduce the incoming sunlight by more than 95 percent for a period of several weeks and affect the climate on earth for a number of years thereafter. During the cold, dark nuclear winter the vegetation which animals and humans need for sustenance would be seriously depleted and great harm would be done to the ecosystem and to human society. In this instance, as so often during the course of his career, Sagan drew upon his extensive knowledge of the forces operating in the atmosphere. However, that knowledge was not used to explain the features of some remote planet but to send a message warning the entire human race of the terrible consequences of nuclear warfare.
Sagan continued to work and proselytize for the furthurance of science until his death in Seattle on December 20, 1996, of pneumonia brought on by a rare bone marrow disease. In July of the following year, upon successful touchdown and deployment on the surface of Mars, the Pathfinder Lander was renamed The Dr. Carl Sagan Memorial Station.
Further Reading
Sagan's career in science and public life to the mid-1970s is covered in Henry S. F. Cooper, Jr., "Profiles (Carl Sagan - I, II)," The New Yorker, June 21 and 28, 1976. Among Sagan's many publications see: Communication with Extraterrestrial Intelligence (1973), The Cosmic Connection (1973), The Dragons of Eden (1977), Broca's Brain (1979), Cosmos (1980), Comet (1985), and Contact (1985).
Additional Sources
Rae Goodell, The Visible Scientist, Little, Brown, 1975.
Carl Sagan, and Richard Turco, A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race, Random House, 1990.[/bibcit.composed
Carl Sagan, Pale Blue Dot: A Vision of the Human Future in Space, Random House, 1994.
Carl Sagan, The Demon-Haunted World: Science as a Candle in the Dark, Random House, 1996.
Carl Sagan, Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium, Random House, 1997.
For more information on Carl Edward Sagan, visit Britannica.com.
Bibliography
See biographies by K. Davidson (1999) and W. Poundstone (1999).
| 1977 | The Dragons of Eden: Speculation on the Evolution of Human Intelligence. The Cornell University astronomer gains his first bestseller with this popularization of scientific ideas of evolution. It would be followed by the equally popular Broca's Brain: Reflections on the Romance of Science (1979). |
| 1981 | Cosmos. This is the companion volume for the astronomer's PBS series on the universe. The highest-rated public television program to date, it reached a worldwide audience of 400 million viewers (to be surpassed in 1990 by Ken Burns's The Civil War) and made Sagan a celebrity and his catchphrase, "billions and billions," common parlance. The book remains on the bestseller list for seventy weeks. |
| 1985 | Contact. The popular astronomer publishes a science fiction thriller about scientist Eleanor Arroway, who receives a message from an alien civilization and is plunged into a media and political frenzy. A film version would appear in 1997. |
Quotes:
"There is today-in a time when old beliefs are withering-a kind of philosophical hunger, a need to know who we are and how we got here. It is an on-going search, often unconscious, for a cosmic perspective for humanity."
"Somewhere, something incredible is waiting to be known."
| Carl Sagan | |
|---|---|
| Born | November 9 1934 Brooklyn, New York |
| Died | December 20 1996 (aged 62) Seattle, Washington, U.S. |
| Residence | Ithaca, New York, U.S. |
| Nationality | |
| Field | Astronomy and planetary science |
| Institutions | Cornell University Harvard University |
| Alma mater | University of Chicago |
| Known for | Search for Extra-Terrestrial Intelligence (SETI) Cosmos: A Personal Voyage Voyager Golden Record Pioneer plaque Contact |
| Notable prizes | Oersted Medal (1990) NASA Distinguished Public Service Medal (twice) Pulitzer Prize for General Non-Fiction (1978) NAS Public Welfare Medal (1994) |
Carl Edward Sagan (November 9 1934 – December 20 1996) was an American
astronomer and astrochemist and a highly successful
popularizer of astronomy, astrophysics, and other natural sciences. He
pioneered exobiology and promoted the Search for Extra-Terrestrial
Intelligence (SETI). He is world-famous for writing popular science books and for
co-writing and presenting the award-winning 1980 television series Cosmos: A
Personal Voyage, which has been seen by more than 600 million people in over 60 countries, making it the most widely
watched PBS program in history.[1] A book to accompany the program was also
published. He also wrote the novel Contact, the basis for the 1997
Robert Zemeckis film of the same name starring
Jodie Foster. During his lifetime, Sagan published more than 600 scientific papers and
popular articles and was author, co-author, or editor of more than 20 books. In his works, he frequently advocated
skeptical inquiry, humanism, and the
Carl Sagan was born in Brooklyn, New York.[2] His parents were Jewish; his father, Sam Sagan, was a garment worker and his mother, Rachel Molly Gruber, was a housewife. Carl was named in honor of Rachel's biological mother, Chaiya/ Clara, "the mother she never knew", in Sagan's words. Sagan graduated from Rahway High School in New Jersey in 1951.[3] He attended the University of Chicago, where he received a bachelor's degree (1955) and a master's degree (1956) in physics, before earning his doctorate (1960) in astronomy and astrophysics. During his time as an undergraduate, Sagan spent some time working in the laboratory of the geneticist H. J. Muller. From 1962 to 1968, he worked at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts.
Sagan lectured annually at Harvard University until 1968, when he moved to Cornell University. He became a full professor at Cornell in 1971 and directed the Laboratory for Planetary Studies there. From 1972 to 1981 he was Associate Director of the Center for Radio Physics and Space Research at Cornell.
Sagan was a leader in the U.S. space program since its inception and worked as an adviser to NASA since the 1950s. One of his many duties during his tenure at the space agency included briefing the Apollo astronauts before their flights to the Moon. Sagan contributed to most of the robotic spacecraft missions that explored the solar system, placing experiments on many of the expeditions. He conceived the idea of adding an unalterable and universal message on spacecraft destined to leave the solar system that could be understood by any extraterrestrial intelligence that might find it. Sagan assembled the first physical message that was sent into space: a gold-anodized plaque, attached to the space probe Pioneer 10, launched in 1972. Pioneer 11, also containing the plaque, was launched the following year. He continued to refine his designs and the most elaborate such message he helped to develop and assemble was the Voyager Golden Record that was sent out with the Voyager space probes in 1977.
Sagan taught at Cornell a course on critical thinking until his death in 1996 from a rare bone marrow disease. The course had only a limited number of seats, although hundreds of students applied each year. From these course application essays, only about 20 were chosen to attend each semester. The course was discontinued after his death. It was resumed by colleague Prof. Yervant Terzian in 2000, who in the true spirit of Sagan continues to challenge students with examination questions such as "Where will humanity stand technologically in a thousand, ten thousand and a million years?", caring not for any particular answer but seeking only to elicit a strong analytical argument for whatever conclusion the student chooses to draw. [1]
Sagan was central to the discovery of the high surface temperatures of the planet Venus. In the early 1960s, no one knew for certain the basic conditions of Venus' surface and Sagan listed the possibilities in a report later depicted for popularization in a Time-Life book, Planets—his own view was that the planet was dry and very hot, as opposed to the balmy paradise others had imagined. He had investigated radio emissions from Venus and concluded that there was a surface temperature of 500 °C (900 °F). As a visiting scientist to NASA's Jet Propulsion Laboratory, he contributed to the first Mariner missions to Venus, working on the design and management of the project. Mariner 2 confirmed his views on the conditions of Venus in 1962.
Sagan was among the first to hypothesize that Saturn's moon Titan and Jupiter's moon Europa may possess oceans, a subsurface ocean, as in the case of Europa, or lakes, thus making the hypothesized water ocean on Europa potentially habitable for life.[4] Europa's subsurface ocean was later indirectly confirmed by the spacecraft Galileo. Sagan also helped solve the mystery of the reddish haze seen on Titan, revealing that it is composed of complex organic molecules constantly raining down to the moon's surface.
He furthered insights regarding the atmospheres of Venus and Jupiter as well as seasonal changes on Mars. Sagan established that the atmosphere of Venus is extremely hot and dense with crushing pressures. He also perceived global warming as a growing, man-made danger and likened it to the natural development of Venus into a hot, life-hostile planet through greenhouse gases. Sagan and his Cornell colleague Edwin Ernest Salpeter speculated about life in Jupiter's clouds, given the planet's dense atmospheric composition rich in organic molecules. He studied the observed color variations on Mars’ surface, concluding that they were not seasonal or vegetation changes as most believed, but shifts in surface dust caused by windstorms.
Sagan is best known, however, for his research on the possibilities of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation.[5]
He is also the 1994 recipient of the Public Welfare Medal, the highest award of the National Academy of Sciences for "distinguished contributions in the application of science to the public welfare."[6]
Sagan was a proponent of the search for extraterrestrial life. He urged the scientific community to listen with radio telescopes for signals from intelligent extraterrestrial lifeforms. So persuasive was he that by 1982, he was able to get a petition advocating SETI published in the journal Science, signed by 70 scientists, including seven Nobel Prize winners. This was a tremendous turnaround in the respectability of this controversial field. Sagan also helped Dr. Frank Drake write the Arecibo message, a radio message beamed into space from the Arecibo radio telescope on November 16, 1974, aimed at informing extraterrestrials about Earth.
Sagan was chief technology officer of the professional planetary research journal, Icarus for twelve years. He co-founded the Planetary Society, the largest space-interest group in the world, with over 1,000,000 members in more than 149 countries, and was a member of the SETI Institute Board of Trustees. Sagan served as Chairman of the Division for Planetary Science of the American Astronomical Society, as President of the Planetology Section of the American Geophysical Union, and as Chairman of the Astronomy Section of the American Association for the Advancement of Science.
At the height of the Cold War, Sagan became involved in public awareness efforts for the effects of nuclear war when a mathematical climate model suggested that a substantial nuclear exchange could upset the delicate balance of life on Earth. He was the last of five authors — the "S" of the "TTAPS" report as the research paper came to be known. He eventually co-authored the scientific paper hypothesising a global nuclear winter following nuclear war.[7] He also co-authored the book A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race, a comprehensive examination of the phenomenon of nuclear winter.
Sagan predicted on ABC's Nightline in 1991 that smoky oil fires in Kuwait set by
Saddam Hussein's army during the first Gulf War would
cause an ecological disaster and send black clouds into the atmosphere resulting in
Sagan is also known for being involved as a researcher in Project A119, a secret US Air Force operation whose purpose was to detonate an atomic bomb on Earth's Moon..[citation needed]
In his later years Sagan advocated the creation of an organized search for near Earth objects that would impact the Earth. ( Head, Tom (2006). Conversations With Carl Sagan. University Press of Mississippi, 86-87. ISBN 1578067367. ) When others suggested creating large nuclear bombs that could be used to alter the orbit of an NEO that was predicted to hit the Earth, Sagan proposed the Deflection Dilemma: If we create the ability to deflect an asteroid away from the Earth, then we also create the ability to deflect an asteroid towards the Earth - providing an evil power with a true doomsday bomb. ("David Morrison - Taking a Hit: Asteroid Impacts & Evolution". [Valley Astronomy Lectures]. 2007-10-03. ) (Sagan, Carl & Ostro, "Long-Range Consequences of Interplanetary Collisions", Issues in Science and Technology Vol X (Number 4))
Sagan believed that the Drake equation suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations pointed out by the Fermi paradox suggests technological civilizations tend to destroy themselves rather quickly. This stimulated his interest in identifying and publicizing ways that humanity could destroy itself, with the hope of avoiding such a cataclysm and eventually becoming a spacefaring species. Sagan's deep concern regarding the potential destruction of human civilization in a nuclear holocaust had been conveyed in a memorable cinematic sequence in the final episode of Cosmos, called "Who Speaks for Earth?". Following his marriage to his third wife (novelist Ann Druyan) in June 1981, Sagan became more politically active—particularly in regard to the escalation of the nuclear arms race under President Ronald Reagan.
In March 1983, hoping to blunt the momentum of the nuclear freeze movement, Reagan announced the Strategic Defense Initiative—a multi-billion dollar project to develop a comprehensive defense against attack by nuclear missiles, which was quickly dubbed the "Star Wars" program. Sagan spoke out against the project, arguing that it was technically impossible to develop a system with the level of perfection required, and far more expensive to build than for an enemy to defeat through decoys and other means—and that its construction would seriously destabilize the nuclear balance between the United States and the Soviet Union, making further progress toward nuclear disarmament impossible.
When Soviet leader Mikhail Gorbachev declared a unilateral moratorium on the testing of nuclear weapons, which would begin on August 6, 1985 — the 40th anniversary of the atomic bombing of Hiroshima — the Reagan administration dismissed the dramatic move as nothing more than propaganda, and refused to follow suit. In response, American anti-nuclear and peace activists staged a series of protest actions at the Nevada Test Site, beginning on Easter Sunday of 1986 and continuing through 1987. Hundreds of people, including such notable figures as Daniel Ellsberg and Martin Sheen, engaged in acts of civil disobedience and were arrested. Carl Sagan, who had been arrested for participating in an anti-war protest during the Vietnam War, was himself arrested on two separate occasions as he climbed over a chain-link fence at the Test Site.
Sagan was a user of marijuana, although he never admitted this publicly during his life. Under the pseudonym "Mr. X", he wrote an essay concerning cannabis smoking in the 1971 book Marihuana Reconsidered, whose editor was Lester Grinspoon.[8][9] In his essay, Sagan commented that marijuana encouraged some of his works and enhanced experiences. After Sagan's death, Grinspoon disclosed this to Sagan's biographer, Keay Davidson. The publishing of this biography, Carl Sagan: A Life, in 1999, brought much media attention to the issue of the use and legalisation of marijuana.[10]
Sagan's capability to convey his ideas allowed many people to better understand the cosmos. He delivered the 1977/1978 Christmas Lectures for Young People at the Royal Institution. He hosted and, with Ann Druyan, co-wrote and co-produced the highly popular thirteen-part PBS television series Cosmos: A Personal Voyage modeled on Jacob Bronowski's The Ascent of Man.
Cosmos covered a wide range of scientific subjects including the origin of life and a perspective of our place in the universe. The series was first broadcast by the Public Broadcasting Service in 1980, winning an Emmy and a Peabody Award. According to the NASA Office of Space Science, it has been since broadcast in more than 60 countries and seen by over 600 million people.[citation needed]
Sagan also wrote books to popularize science, such as Cosmos, which reflected and expanded upon some of the themes of A Personal Voyage, and became the best-selling science book ever published in English,[11] The Dragons of Eden: Speculations on the Evolution of Human Intelligence, which won a Pulitzer Prize, and Broca's Brain: Reflections on the Romance of Science. Sagan also wrote the best-selling science fiction novel Contact, but did not live to see the book's 1997 motion picture adaptation, which starred Jodie Foster and won the 1998 Hugo Award.
From Cosmos and his frequent appearances on The Tonight Show, Sagan became associated with the catch phrase "billions and billions." Sagan never actually used the phrase in Cosmos series,[12] however his frequent use of term billions, and distinctive delivery with emphasis on the “b”, made him a favorite meme of performers and comedy routines of Johnny Carson, Gary Kroeger, Mike Myers, Bronson Pinchot, Harry Shearer and others. Sagan took this in good humor, and his final book was entitled Billions and Billions and opened with a tongue-in-cheek discussion of this catch phrase. The indefinite and fictitious number Sagan has arisen in popular culture to indicate a count greater than 4 billion.
He wrote a sequel to Cosmos, Pale Blue Dot: A Vision of the Human Future in Space, which was selected as a notable book of 1995 by The New York Times. He appeared on PBS' Charlie Rose program in January 1995.[13] Sagan also wrote an introduction for the bestselling book by Stephen Hawking, A Brief History of Time.
Sagan caused mixed reactions among other professional scientists. On the one hand, there was general support for his popularization of science, his efforts to increase scientific understanding among the general public, and his positions in favor of scientific skepticism and against pseudoscience; most notably his thorough debunking of the book Worlds in Collision by Immanuel Velikovsky. For as popular as this debunking was with science writers and the public, many of its arguments were flawed[14] and Appendix 3 on the cooling of Venus has nothing to do with cooling, but instead is a trivial identity that merely equates the heat radiated to Venus by the Sun in one hour at 6000K to the heat radiated from Venus in 3500 years at 79K.[15] On the other hand, there was some unease that the public would misunderstand some of the personal positions and interests that Sagan took as being part of the scientific consensus.
Late in his life, Sagan's books developed his skeptical, naturalistic view of
the world. In The Demon-Haunted World: Science as a Candle in the Dark, he presented tools for testing arguments and
detecting fallacious or fraudulent ones, essentially advocating wide use of critical thinking and the
In 2006, Ann Druyan edited Sagan's 1985 Glasgow Gifford Lectures in Natural Theology into a new book, The Varieties of Scientific Experience: A Personal View of the Search for God, in which he elaborates on his views of divinity in the natural world.
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Personality. This concern has been noted on the talk page where it may be discussed whether or not to include such information. |
In 1966, Sagan was asked to contribute an interview about the possibility of extraterrestrials to a proposed introduction to the film 2001: A Space Odyssey. Sagan responded by saying that he wanted editorial control and a percentage of the film's takings, which was rejected.[16]
In 1994, Apple Computer began developing the Power Macintosh 7100. They chose the internal code name "Carl Sagan", the in-joke being that the mid-range PowerMac 7100 would make Apple "billions and billions."[2] Though the project name was strictly internal and never used in public marketing, when Sagan learned of this internal usage he sued Apple Computer to force the use of a different project name. Other models released conjointly had code names such as "Cold fusion" and "Piltdown Man", and he was displeased at being associated with what he considered pseudoscience. (He was at the time writing a book debunking pseudoscience.) Though Sagan lost the suit, Apple engineers complied with his demands anyway, renaming the project "BHA" (for Butt-Head Astronomer). Sagan promptly sued Apple for libel over the new name, claiming that it subjected him to contempt and ridicule, but he lost this lawsuit as well. Still, the 7100 saw another name change: it was finally referred to internally as "LAW" (Lawyers Are Wimps).[17][18]
Sagan wrote frequently about religion and the relationship between religion and science,
expressing his skepticism about many conventional conceptualizations of God.
Sagan once stated, for instance, that "The idea that God is an oversized white male with a flowing beard, who sits in the sky and
tallies the fall of every sparrow is ludicrous. But if by 'God,' one means the set of physical
laws that govern the universe, then clearly there is such a God. This God is emotionally unsatisfying... it does not make
much sense to pray to the law of
Sagan married three times: biologist Lynn Margulis, mother of Dorion Sagan and Jeremy Sagan, in 1957; artist Linda Salzman, mother of Nick Sagan, in 1968; and author Ann Druyan, mother of Alexandra Rachel (Sasha) and Samuel Democritus (Sam), in 1981. His marriage to Druyan continued until his death in 1996.
Isaac Asimov described Sagan as one of only two people he ever met who was just plain smarter than Asimov himself. The other was computer scientist and expert on artificial intelligence Marvin Minsky.
Sagan had some interest in UFO reports from at least 1964, when he had several conversations on the subject with Jacques Vallee.[21] Though quite skeptical of any extraordinary answer to the UFO question, Sagan thought that science should study the phenomenon, at least because there was widespread public interest in UFO reports.
Stuart Appelle notes that Sagan "wrote frequently on what he perceived as the logical and empirical fallacies regarding UFOs and the abduction experience. Sagan rejected an extraterrestrial explanation for the phenomenon but felt there were both empirical and pedagogical benefits for examining UFO reports and that the subject was, therefore, a legitimate topic of study."[22]
In 1966, Sagan was a member of the Ad Hoc Committee to Review Project Blue Book. The committee concluded that the U.S. Air Force's Project Blue Book had been lacking as a scientific study, and recommended a university-based project to give the UFO phenomenon closer scientific scrutiny. The Condon Committee (1966-1968), led by physicist Edward Condon, and their still-controversial final report, formally concluded that there was nothing anomalous about UFO reports.
Ron Westrum writes that "The high point of Sagan's treatment of the UFO question was the AAAS's symposium in 1969. A wide range of educated opinions on the subject were offered by participants, including not only proponents as James McDonald and J. Allen Hynek but also skeptics like astronomers William Hartmann and Donald Menzel. The roster of speakers was balanced, and it is to Sagan's credit that this event was presented in spite of pressure from Edward Condon".[21] With physicist Thornton Page, Sagan edited the lectures and discussions given at the symposium; these were published in 1972 as UFO's: A Scientific Debate. Jerome Clark writes that Sagan's perspective on UFO's irked Condon: "... though a skeptic, [Sagan] was too soft on UFOs for Condon's taste. In 1971, he considered blackballing Sagan from the prestigious Cosmos Club".[23]
Some of Sagan's many books examine UFOs (as did one episode of Cosmos) and he recognized a religious undercurrent to the phenomenon. However, Westrum writes that "Sagan spent very little time researching UFOs ... he thought that little evidence existed to show that the UFO phenomenon represented alien spacecraft and that the motivation for interpreting UFO observations as spacecraft was emotional".[21]
It is sometimes noted that Sagan's generally skeptical attitude to UFOs conflicted sharply with his views in a 1966 book he wrote with Russian astronomer and astrophysicist I.S. Shklovskii, Intelligent Life in the Universe. Here Sagan instead argued that technologically advanced alien civilizations were common and he considered it very probable that Earth had been visited many times in the past. Yet only a few years later in UFO's: A Scientific Debate, Sagan was now highly skeptical of interstellar visitation. As to the physical possibility of interstellar travel, Sagan brought up the proposed Bussard ramjet as an interstellar vehicle. While not terribly practical, Sagan thought such proposed propulsion systems were nevertheless important because they demonstrated that there were conceivable ways of accomplishing interstellar travel "without bumping into fundamental physical constraints. And this suggests that it is premature to say that interstellar space flight is out of the question." But to this Sagan added, "I believe the numbers work out in such a way that UFO's as interstellar vehicles is extremely unlikely, but I think it is an equally bad mistake to say that interstellar space flight is impossible."
Sagan again revealed his views on interstellar travel in his 1980 Cosmos series. He rejected the idea that UFOs are visiting Earth, maintaining that the chances any alien spacecraft would visit the Earth are vanishingly small. However, in another episode he said the stars would "beckon" to humanity, and described the Bussard ramjet as one way humans might achieve interstellar travel. In one of his last written works, Sagan again claimed that there was no evidence that aliens have actually visited the Earth, either in the past or present (Sagan, 1996: 81-96, 99-104).
After a long and difficult fight with myelodysplasia, which included three bone marrow transplants, Sagan died of pneumonia at the age of 62, leaving behind a wife and five children on December 20, 1996, at the Fred Hutchinson Cancer Research Center in Seattle, Washington. Sagan was a significant figure, and his supporters credit his importance to his popularization of the natural sciences, opposing both restraints on science and reactionary applications of science, defending democratic traditions, resisting nationalism, defending humanism, and arguing against geocentric and anthropocentric views.
The landing site of the unmanned Mars Pathfinder spacecraft was renamed the Carl Sagan Memorial Station on July 5 1997. Asteroid 2709 Sagan is also named in his honor.
The 1997 movie Contact, based on Sagan's novel of the same name and finished after his death, ends with the dedication "For Carl."
On November 9, 2001, on what would have been Sagan’s 67th birthday, the NASA Ames Research Center dedicated the site for the Carl Sagan Center for the Study of Life in the Cosmos. "Carl was an incredible visionary, and now his legacy can be preserved and advanced by a 21st century research and education laboratory committed to enhancing our understanding of life in the universe and furthering the cause of space exploration for all time", said NASA Administrator Daniel Goldin. Ann Druyan was at the center as it opened its doors on October 22, 2006.
Sagan's son, Nick Sagan, wrote several episodes in the Star Trek franchise. In an episode of Star Trek: Enterprise entitled "Terra Prime", a quick shot is shown of the relic rover Sojourner, part of the Mars Pathfinder mission, placed by a historical marker at Carl Sagan Memorial Station on the Martian surface. The marker displays a quote from Sagan: "Whatever the reason you're on Mars, I'm glad you're there, and I wish I was with you."
Sagan has at least two awards named in his honour: the Carl Sagan Memorial Award presented jointly since 1997 by the American Astronautical Society (AAS) and the Planetary Society; and the Carl Sagan Award for Public Understanding of Science presented by Council of Scientific Society Presidents (CSSP). Sagan himself was the first recipient of the CSSP award in 1993.[24]
Sagan's student Steve Squyres led the team that landed the Spirit Rover and Opportunity Rover successfully on Mars in 2004.