Carl
Sagan
Born November 9, 1934
Brooklyn, New York
Died December 20, 1996
Seattle, Washington
Carl
Edward Sagan (November 9, 1934 – December 20, 1996) was an American
astronomer and astrobiologist 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 scientific method.
Sagan of Astronomy
Department, Cornell University, 1969Carl 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 (NJ) High School 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 taught 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 unmanned missions
that explored the solar system, placing experiments on many robotic
space 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 tried to attend. He chose about 20 students
who were allowed to enroll by reading huge piles of application essays.
The course was discontinued after his death.
Scientific achievements
A still from CosmosSagan 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 (which were 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[4] and Jupiter's moon
Europa may possess oceans (a subsurface ocean, in the case of Europa)
or lakes, thus making the hypothesized water ocean on Europa potentially
habitable for life. 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
speculated (along with his Cornell colleague Edwin Ernest Salpeter)
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]
Scientific advocacy
Planetary Society members at the organization's founding. Carl Sagan
is seated to the right.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.
CETI conference,
1972He was editor-in-chief of Icarus (a professional journal concerning
planetary research) for 12 years. He co-founded the Planetary Society,
the largest space-interest group in the world, with over 100,000 members
in more than 140 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 that predicted nuclear
winter[6] would follow nuclear war. 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 famously 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 a worldwide ecological
disaster of black clouds resulting in global cooling. Retired atmospheric
physicist and climate change skeptic Fred Singer dismissed Sagan's prediction
as nonsense, predicting that the smoke would dissipate in a matter of
days. In his book The Demon-Haunted World (see below), Sagan gave a
list of errors he had made (including his predictions about the effects
of the Kuwaiti oil fires) as an example of how science is tentative,
a self-correcting process.
Sagan is also known
for being involved as a researcher in Project A119, a secret US Air
Force operation whose purpose was to explode an atomic bomb on Earth's
Moon.
Social concerns
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 (the Fermi paradox) suggests that 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 in the early 1970sSagan'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 novelist
Ann Druyan (his third wife) 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.
Carl Sagan was an
avid 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.[7] 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.
When the biography, entitled Carl Sagan: A Life, was published in 1999,
the marijuana exposure stirred some media attention.[8][9][10]
Popularization
of science
Sagan in 1980Sagan'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).
Sagan with a model
of the Viking Lander probes which would land on Mars. Sagan examined
possible landing sites for Viking along with Mike Carr and Hal Masursky.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. It won 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.
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." (He never actually
used that phrase in Cosmos,[12] but his distinctive delivery and frequent
use of billions (with noted emphasis on the opening "b") made
this a favorite phrase of Johnny Carson, Gary Kroeger, Mike Myers, Bronson
Pinchot, Harry Shearer and others, doing many affectionate impressions
of him. Sagan took this in good humor, and his final book was entitled
Billions and Billions (see below) and opened with a tongue-in-cheek
discussion of this catch phrase.) A humorous unit of measurement, the
Sagan, has now been coined to stand for any count of at least 4,000,000,000.
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. (video) Carl Sagan also
wrote an introduction for the bestselling book by Stephen Hawking, A
Brief History of Time.
Sagan presents a
speculation concerning the origin of the swastika symbol in his book,
Comet. Sagan hypothesized that a comet approached so close to Earth
in antiquity that the jets of gas streaming out of it were visible,
bent by the comet's rotation. The book Comet reproduces an ancient Chinese
manuscript that shows comet tail varieties; most are variations on simple
comet tails, but the last shows the comet nucleus with four bent arms
extending from it, showing a swastika.
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. 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. Sagan's arguments
against Velikovsky's catastrophism have been criticized by some of his
colleagues. Robert Jastrow of NASA's Goddard Institute for Space Studies
wrote: "Professor Sagan's calculations, in effect, ignore the law
of gravity. Here, Dr. Velikovsky was the better astronomer."
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 scientific
method. The compilation, Billions and Billions: Thoughts on Life and
Death at the Brink of the Millennium, published in 1997 after Sagan's
death, contains essays written by Sagan, such as his views on abortion,
and his widow Ann Druyan's account of his death as a skeptic, agnostic,
and freethinker.
In 2006, Ann Druyan
edited Sagan's 1985 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.
Personality
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. According to an unsourced anecdote in The Independent,
Sagan "responded by saying that he wanted editorial control and
a percentage of the film's takings, which was rejected."[13]
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."[14] 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
use 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.
Though Sagan lost the suit, Apple engineers complied with his demands
anyway, renaming the project "BHA" (for Butt-Head Astronomer).[citation
needed] Sagan promptly sued Apple for libel over the new name, claiming
that it subjected him to contempt and ridicule, but lost this lawsuit
as well. Still, the 7100 saw another name change: it was finally referred
to internally as "LAW" (Lawyers Are Wimps).
Sagan with DruyanSagan
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 gravity."[15] Sagan is
also widely regarded as a freethinker or skeptic; one of his most famous
quotations (as seen in Cosmos) was "Extraordinary claims require
extraordinary evidence." (This was actually based on a nearly identical
earlier quote by fellow CSICOP founder Marcello Truzzi, "Extraordinary
claims require extraordinary proof."[16] The quote is also known,
under different wording, as the principle of Laplace — attributed
to Pierre-Simon Marquis de Laplace (March 23, 1749 – March 5,
1827), a French mathematician and astronomer: "The weight of evidence
for an extraordinary claim must be proportioned to its strangeness.")
Sagan married three
times: the famous 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 Sasha and Sam) in 1981, to whom
he remained married until his death in 1996.
Isaac Asimov described
Sagan as one of the only two people he ever met who were just plain
smarter than Asimov himself. The other was computer scientist and expert
on artificial intelligence, Marvin Minsky.
Sagan and UFOs
Sagan had some interest in UFO reports from at least 1964, when he had
several conversations on the subject with Jacques Vallee (Westrum 37).
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" (Appelle 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" (Westrum 37-38). 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"
(Clark 603).
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" (Westrum 37).
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).
Death and legacy
Sagan in 1996, shortly before his deathAfter 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 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
(see above), 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's student,
Steve Squyres, would lead the team that landed the Spirit Rover and
Opportunity Rover successfully on Mars in 2004.
Carl Edward Sagan
was born Nov. 9, 1934, in Brooklyn, N.Y. At Cornell since 1968, Sagan
received a bachelor's degree in 1955 and a master's degree in 1956,
both in physics, and a doctorate in astronomy and astrophysics in 1960,
all from the University of Chicago. He taught at Harvard University
in the early 1960s before coming to Cornell, where he became a full
professor in 1971.
Sagan played a leading
role in NASA's Mariner, Viking, Voyager and Galileo expeditions to other
planets. He has received NASA Medals for Exceptional Scientific Achievement
and twice for Distinguished Public Service and the NASA Apollo Achievement
Award.
His research has
focused on topics such as the greenhouse effect on Venus; windblown
dust as an explanation for the seasonal changes on Mars; organic aerosols
on Titan, Saturn's moon; the long-term environmental consequences of
nuclear war; and the origin of life on Earth. A pioneer in the field
of exobiology, he continued to teach graduate and undergraduate students
in courses in astronomy and space sciences and in critical thinking
at Cornell.
The breadth of his
interests were made evident in October 1994, at a Cornell-sponsored
symposium in honor of Sagan's 60th birthday. The two-day event featured
speakers in areas of planetary exploration, life in the cosmos, science
education, public policy and government regulation of science and the
environment -- all fields in which Sagan had worked or had a strong
interest.
Sagan was the recipient
of numerous of awards in addition to his NASA recognition. He has received
22 honorary degrees from American colleges and universities for his
contributions to science, literature, education and the preservation
of the environment and many awards for his work on the long-term consequences
of nuclear war and reversing the nuclear arms race.
Among his other
awards have been: the John F. Kennedy Astronautics Award of the American
Astronautical Society; the Explorers Club 75th Anniversary Award; the
Konstantin Tsiolkovsky Medal of the Soviet Cosmonauts Federation and
the Masursky Award of the American Astronomical Society. He also was
the 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."
Sagan was elected
chairman of the Division of Planetary Sciences of the American Astronomical
Society, president of the Planetology Section of the American Geophysical
Union and chairman of the Astronomy Section of the American Association
for the Advancement of Science. For 12 years he was editor of Icarus,
the leading professional journal devoted to planetary research.
He is co-founder
of The Planetary Society, a 100,000-member organization and the largest
space-interest group in the world. The society supports major research
programs in the radio search for extraterrestrial intelligence, the
investigation of near-Earth asteroids and, with the French and Russian
space agencies, the development and testing of balloon and mobile robotic
exploration of Mars. Sagan also was Distinguished Visiting Scientist
at the Jet Propulsion Laboratory in California and was contributing
editor of Parade magazine, where he published many articles about science
and, most recently, about the disease that he has battled for the past
two years.
Sagan is survived
by his wife and collaborator, Ann Druyan; his sister, Cari Sagan Greene;
five children, Dorion, Jeremy, Nicholas, Sasha and Sam; and a grandson,
Tonio.