- Person
- Carl Sagan
- Lived
- 1934–1996
- Field
- Astronomy, planetary science
- From
- American
The story
By 1980 Carl Sagan was one of the best-known scientists in the world. A Cornell astronomer who had worked on the Mariner, Viking and Voyager missions, he was convinced that exploring the planets and searching for life beyond Earth needed more than scientists and officials behind it. It needed an organised public that could speak up for missions when budgets were tight.
In 1980 he co-founded the Planetary Society with Bruce Murray and Louis Friedman. Sagan became its first president. The society invited ordinary people who loved space to join, and it set out to support the scientific exploration of the solar system and the search for extraterrestrial life. Its magazine, The Planetary Report, opened with Sagan's own argument for planetary exploration.
Sagan used his fame to give the society influence. According to its history, it helped protect NASA's search for extraterrestrial intelligence from cancellation by Congress in 1981, and that same year it partnered with NASA to fund Suitcase SETI, which grew into the first dedicated high-resolution survey for alien signals. In 1983 the society urged NASA to send a mission to Saturn and its moon Titan, years before the Cassini-Huygens spacecraft launched in 1997. In the 1990s it began campaigning for a mission to Jupiter's moon Europa, which eventually became NASA's Europa Clipper.
Sagan led the society until his death in 1996, while also serving the professional community. For 12 years he was editor in chief of Icarus, the leading journal of planetary research, and he chaired the Division for Planetary Sciences of the American Astronomical Society. The Carl Sagan Memorial Award, presented jointly by the American Astronomical Society and the Planetary Society since 1997, honours his legacy.
The organisation he helped create now counts about 40,000 members in more than 80 countries. Its campaigns have been credited with helping save the New Horizons mission to Pluto, and it has built and flown its own solar-sail spacecraft, LightSail 1 and LightSail 2, funded by its members. Bill Nye, who studied astronomy with Sagan at Cornell, became its executive director in 2010.
Why it matters
The Planetary Society gave the public a lasting voice in space exploration, and its advocacy has helped keep missions to Pluto, Europa and beyond alive.
About Carl Sagan
Brooklyn-born astronomer who explained the Venus greenhouse, helped send humanity’s messages on Pioneer and Voyager, and taught Cosmos viewers worldwide to look at the universe with wonder and doubt.
More about Carl Sagan
- Carl Sagan explained why Venus is a furnaceIn the early 1960s Carl Sagan argued from radio data that Venus's surface was about 500 °C because of a greenhouse effect, a conclusion confirmed by Mariner 2 in 1962.
- Carl Sagan inspired a generation of science communicatorsCarl Sagan invited a 17-year-old Neil deGrasse Tyson to Cornell and taught Bill Nye astronomy, inspiring a generation of scientists and science popularisers.
- Carl Sagan showed Mars's changing colours were dustMany astronomers thought seasonal colour changes on Mars were spreading vegetation. Carl Sagan showed they were shifts in surface dust driven by windstorms.
- Carl Sagan asked Voyager to photograph the Pale Blue DotAt Carl Sagan's urging, Voyager 1 turned its camera homeward on February 14, 1990, and photographed Earth from about 6 billion kilometres away as a tiny pale blue dot.
- Carl Sagan designed humanity's first message to the starsGiven just three weeks by NASA, Carl Sagan and Frank Drake designed the Pioneer plaque, a message to any alien finders, now leaving the solar system aboard two spacecraft.
- Carl Sagan made the search for alien life respectableIn 1982 Carl Sagan published a petition in the journal Science supporting the search for extraterrestrial intelligence, signed by 70 scientists including seven Nobel laureates.
- Carl Sagan foresaw ocean worlds on Titan and EuropaCarl Sagan was among the first to suggest that Saturn's moon Titan might have surface liquids and that Jupiter's moon Europa might hide an ocean of water beneath its ice.
- Carl Sagan chaired the Voyager Golden Record committeeFor the Voyager probes launched in 1977, Carl Sagan chaired the committee that chose the Golden Record's contents, including greetings in 55 languages and 116 images of Earth.
- Carl Sagan warned Congress about climate change in 1985Drawing on his study of Venus, Carl Sagan testified to the US Congress in 1985 that the greenhouse effect would change Earth's climate.
- Kip Thorne helped Carl Sagan imagine Contact's wormholesFor his 1985 novel Contact, Carl Sagan asked his friend Kip Thorne how a wormhole might work. The book sold 1.7 million copies in two years and became a 1997 film.
- Carl Sagan's Cosmos reached 500 million peopleCosmos: A Personal Voyage, first broadcast in 1980, has been seen by at least 500 million people in 60 countries, and its companion book was the best-selling science book of its time.
- Carl Sagan won a Pulitzer Prize for The Dragons of EdenCarl Sagan's 1977 book The Dragons of Eden, on the evolution of human intelligence, won the 1978 Pulitzer Prize for General Nonfiction and introduced his Cosmic Calendar.
- Carl Sagan gave the public a baloney detection kitIn The Demon-Haunted World (1995), Carl Sagan offered readers a toolkit for critical thinking and popularised the rule that extraordinary claims require extraordinary evidence.
- Carl Sagan warned the world about nuclear winterIn 1983 Carl Sagan co-authored the TTAPS study warning that a nuclear war could cool the planet, work honoured in 2022 with the Future of Life Award.
Sources
- Carl Sagan The Planetary Society
- Carl Sagan Wikipedia
- The Planetary Society Wikipedia
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