Carl Sagan Trivia
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60 free Carl Sagan trivia questions with answers — science & nature quiz, new questions added Aug 2026.
This Carl Sagan trivia quiz covers the astronomer who made half a billion people care about the universe. The easy questions handle Cosmos, Pale Blue Dot, Contact, the Golden Record, the Planetary Society and 'billions and billions'. From there it moves through the life: the garment-worker father, the 1939 World's Fair, the librarian who first handed him a book of movie stars, the University of Chicago at 16, the Air Force plan to detonate a bomb on the Moon, and the Harvard tenure that never came. The harder end covers the hot Venus prediction, the moons he suspected of hiding oceans, the journal he edited, the Cornell astronomer who hired him, the Baloney Detection Kit, the origins of the extraordinary-claims maxim, the TTAPS paper, the arrests in Nevada, the pseudonymous essay on marijuana, Apple's Butt-Head Astronomer, the licence plate on the Porsche and the science-fiction writer who said only two people out-thought him. Every answer was checked against Sagan's encyclopaedia entry before publishing and the supporting sentence is stored with each question. Our space and astronomy quizzes are the natural next stop.
30 of 60 questions with answers and explanations. Play the quiz
Q 01Which animated-comedy creator paid for the Library of Congress to buy Sagan's papers and co-produced the 2014 Cosmos revival?
Seth MacFarlane
Seth MacFarlane. The Family Guy creator, a space buff since childhood, called Sagan's work a profound influence on his life and dismissed much of television's science as 'fluff'.
Q 02For which book did Sagan win the 1978 Pulitzer Prize for General Nonfiction?
The Dragons of Eden
The Dragons of Eden. The astronomer won his Pulitzer not for a book about space but for one speculating on how human intelligence evolved.
Q 03Which director filmed Sagan's novel Contact, finishing it after the author's death?
Robert Zemeckis
Robert Zemeckis. Sagan was co-producing the film with Ann Druyan when he died in the middle of the shoot, so it fades out on the dedication 'For Carl'.
Q 04In which New York City borough was Sagan born in 1934?
Brooklyn
Brooklyn. As a boy there he asked everyone what the stars were and got answers like 'They're lights in the sky, kid', so he took the question to the public library.
Q 05What was the trade of Sagan's Ukrainian-born father, Samuel?
Garment worker
Garment worker. Samuel cut coat patterns from stacks of cloth with what Carl called 'a very scary power saw', and by the late 1940s he was managing the factory.
Q 06Sagan described a visit to which 1939 event, home of the Futurama exhibit, as a defining moment?
The New York World's Fair
The New York World's Fair. Its buried time capsule, meant for people of the far future, thrilled the small boy, and as an adult he helped launch time capsules of his own aboard space probes.
Q 07When the young Sagan asked a librarian for something on the stars, what did she first bring him?
Portraits of Hollywood actors
Portraits of Hollywood actors. The picture book was full of stars like Clark Gable and Jean Harlow, and the librarian found his complaint hilarious before fetching the right kind of book.
Q 08In Sagan's Contact, the aliens' first message turns out to contain a replay of which television broadcast?
Hitler opening the Berlin Olympics
Hitler opening the Berlin Olympics. In the story the 1936 Games were the first television signal strong enough to leave Earth, so they were the first thing listeners 26 light-years away could send back.
Q 09Sagan's high school contest entry compared human contact with advanced aliens to what?
Native Americans meeting Europeans
Native Americans meeting Europeans. The contest's theme was Columbus, then a revered figure, and calling his arrival a disaster for the people he met was close to unsayable for a schoolboy around 1950.
Q 10Which university, then home to physicist Enrico Fermi, admitted Sagan when he was just 16?
The University of Chicago
The University of Chicago. It was one of the few colleges that would take a 16-year-old, and its Great Books curriculum had the future astronomer reading Aristotle and Freud alongside his physics.
Q 11Who supervised Sagan's doctoral thesis on the physical study of the solar system's worlds?
Gerard Kuiper
Gerard Kuiper, of Kuiper belt fame, was then almost the only full-time planetary astronomer, and Sagan credited him with the habit of testing any idea with quick sums on the back of an envelope.
Q 12Secret 1958 Project A119, on which the young Sagan worked, planned a nuclear detonation where?
On the Moon
On the Moon. The US Air Force wanted a blast visible from Earth as a show of strength in the space race, and Sagan's job was to model the dust cloud it would throw up.
Q 13In the early 1960s Sagan argued that which planet, then imagined by some as a balmy paradise, was a searing desert?
Venus
Q 21Sagan showed that the seasonal colour changes on Mars, long blamed on vegetation, were really caused by what?
Windblown dust
Windblown dust. The irony is that the darkening had been the best evidence for life on Mars, and it was knocked down by the astronomer who most wanted to find some.
Q 22In 1985 Sagan testified to the US Congress about which threat to Earth's climate?
The greenhouse effect
The greenhouse effect. He came to the subject from astronomy: his early research had shown how the same process, run out of control, could turn a neighbouring planet into a furnace.
Q 23Sagan spent twelve years editing which planetary science journal, named after a figure from Greek myth?
Icarus
Venus. Its radio emissions convinced him the surface was hot enough to melt lead, and in 1962 Mariner 2, the first probe to report back from another planet, proved him right.
Q 14Nobel laureate Harold Urey, once Sagan's adviser, wrote a letter opposing his bid for tenure at which university?
Harvard
Harvard. Urey thought his former student speculated too freely and courted publicity; Sagan, unaware of the letter, was turned down and in 1968 moved to Cornell for the rest of his career.
Q 15Which future TV science presenter took Sagan's astronomy class while studying engineering at Cornell?
Bill Nye
Bill Nye. At his ten-year reunion he won five minutes with Sagan to pitch a children's show about bridges and bicycles, and was told to stick to pure science because kids 'resonate' to it.
Q 16At Cornell, Sagan directed the Laboratory for what?
Planetary Studies
Planetary Studies. Much of the lab's work was chemistry: Sagan's team made amino acids from simple gases to test whether the building blocks of life could form on other worlds.
Q 17As a NASA adviser, Sagan briefed which astronauts before their flights?
The Apollo crews
The Apollo crews. He also lobbied to have the first men back from the lunar surface kept in quarantine, in case they carried alien microbes home with them.
Q 18Sagan devised a message for any alien finders, an engraved plaque bolted to which 1972 probe?
Pioneer 10
Pioneer 10. NASA gave him three weeks to prepare it, and because his wife Linda drew the man and woman unclothed, some newspapers censored the picture before printing it.
Q 19Alongside Bach and Beethoven, which rock and roll star's music is on the Golden Record launched in 1977?
Chuck Berry
Chuck Berry. Sagan first called 'Johnny B. Goode' awful, then defended it: when a folklorist on the panel sneered that rock was adolescent, he replied that Earth has plenty of adolescents.
Q 20Sagan and physicist Edwin Salpeter imagined balloon-like creatures called 'floaters' drifting through the clouds of which planet?
Jupiter
Jupiter. In a 1976 paper the pair reasoned that an atmosphere so dense and so rich in organic molecules might support life, even on a world with no solid ground to stand on.
Icarus. When he took over in 1968 many astronomers still saw planetary science as a fringe pursuit, and by the time he stepped down it had become the field's leading journal.
Q 24Sagan co-founded which organisation in 1980 and served as its first president?
The Planetary Society
The Planetary Society. Sagan, Bruce Murray and Louis Friedman set it up to prove, simply by its existence, that the public wanted other worlds explored, and to wave that fact at politicians.
Q 25Sagan's first wife, who later updated his Encyclopaedia Britannica entry on Life, was which biologist?
Lynn Margulis
Lynn Margulis. She met Sagan at 16, and after their marriage ended she became a leading evolutionary biologist by arguing that complex cells arose from mergers of bacteria.
Q 26Sagan delivered the 1977 Royal Institution Christmas Lectures on what subject?
The Planets
The Planets. Half of his six lectures dwelt on a single one, Mars, because the Viking landers he had helped to target had touched down there just the year before.
Q 27Cosmos drew notably on which earlier documentary series by Jacob Bronowski?
The Ascent of Man
The Ascent of Man. The debt was direct: its producers Adrian Malone and David Kennard moved to California and made Cosmos in the same style, one presenter roaming the world with a personal view.
Q 28The production of Cosmos recreated which lost building of the ancient world?
The Library of Alexandria
The Library of Alexandria. The great halls Sagan seems to stroll through were an intricate miniature, with the presenter placed inside the model by special effects.
Q 29Besides Bach and Vivaldi, which electronic composer's music featured prominently in Cosmos?
Vangelis
Vangelis. A movement of his 1975 album Heaven and Hell became the series theme, and the worldwide success of Cosmos carried the Greek composer's music to a far bigger audience.
Q 30Sagan wrote the introduction to which physicist's runaway bestseller?
Stephen Hawking's A Brief History of Time
Stephen Hawking's A Brief History of Time. Sagan's introduction recalls wandering into a London ceremony in 1974 and watching a young man in a wheelchair slowly sign a book that Isaac Newton had signed.