Comets Trivia
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54 free Comets trivia questions with answers — science & nature quiz, new questions added Sep 2026.
This comets trivia quiz covers the icy wanderers of the Solar System from Aristotle's atmospheric theory to Philae bouncing onto a comet's surface. The easy questions are ones any stargazer can attempt: what a comet is made of, what makes the tail and which way it points, the most famous comet of all, where the Perseids come from and which comet crashed into Jupiter in 1994. From there it moves into the physics and the maps: the Kuiper belt and Oort cloud, short- and long-period orbits, the coma, the ion and dust tails, jets, sungrazers and interstellar visitors. The harder end is for astronomy buffs: Tycho's parallax of 1577, Newton's comet of 1680, Halley's 1705 prediction and the three French mathematicians who refined it, Fred Whipple's dirty snowball, the 1910 cyanogen panic, Giotto's 596-kilometre pass, Deep Impact's crater, Stardust's glycine, the record tails and comas of Hyakutake and 1811, Kohoutek's fizzle, Heaven's Gate and Hale-Bopp, the IAU naming scheme and comets 1I, 2I and 3I. Every answer was checked against encyclopaedia entries on comets, individual comets and the missions that visited them before publishing, and the supporting sentence is stored with each question. If you enjoy this one, try our Halley's Comet, solar system and space exploration quizzes next.
30 of 54 questions with answers and explanations. Play the quiz
Q 01What are comet nuclei mostly made of?
Ice and dust
Ice and dust: comets have been called 'dirty snowballs', but later observations suggested 'icy dirtballs' fits them better.
Q 02Why did the Philae lander soon fall silent after touching down on a comet in 2014?
It came to rest in shadow
It came to rest in shadow: its harpoons failed, so it bounced into a shaded spot where its solar panels got too little light, though it woke again in June 2015.
Q 03In which direction does a comet's ion tail point?
Directly away from the Sun
Directly away from the Sun: sunlight ionises the gas and the solar wind sweeps it outward, while the separate dust tail curves.
Q 04Which process builds a comet's coma as sunlight warms it?
Outgassing
Outgassing: the material it frees streams out from the comet and forms its tails.
Q 05The name comet comes from a Greek term meaning what?
Wearing long hair
The Greeks called it the long-haired star.
Q 06Where do most short-period comets originate?
The Kuiper belt and scattered disc
The Kuiper belt and scattered disc lie beyond Neptune, where the gravity of the giant planets nudges icy bodies inward to become short-period comets.
Q 07The Oort cloud is named after an astronomer from which country?
Netherlands
Jan Oort of the Netherlands proposed the cloud in the 1950s as the distant reservoir that keeps sending long-period comets toward the Sun.
Q 08Many Romans believed the comet that shone over Rome in 44 BC was whose soul?
Julius Caesar
Julius Caesar's statues were given a star on the head, because Romans took the comet seen during games Augustus held in his honour as Caesar's soul.
Q 09In which 2021 Netflix satire do two astronomers struggle to warn the world about a planet-killing comet?
Don't Look Up
Don't Look Up used its comet as an allegory for climate change, mocking how politicians and the media shrug off scientists' warnings.
Q 10In 2014, NASA spacecraft took shelter behind which planet as Comet Siding Spring's dust swept past?
Mars
Mars passed through the comet's dust for hours, so NASA parked its Mars orbiters on the planet's far side at the riskiest moment, then used them to study the flyby.
Q 11Which Sun-watching spacecraft, launched in 1995, had discovered its 5,000th comet by 2024?
SOHO
SOHO mostly spots sungrazers, and most of its comets, including the 5,000th, were found by volunteer citizen scientists combing its images.
Q 12Which was the first detected interstellar comet, spotted in 2019?
2I/Borisov
2I/Borisov was spotted by Crimean amateur astronomer Gennadiy Borisov, and astronomers worldwide then confirmed its path came from interstellar space.
Q 13After comets appeared, which Roman emperor reportedly had prominent nobles executed to deflect the omen from himself?
Nero
Nero took comets as omens that a ruler would fall, and reportedly deflected them by executing prominent nobles.
Q 21Who used the parallax of the Great Comet of 1577 to show comets lie beyond Earth's atmosphere?
Tycho Brahe
Tycho Brahe's measurements placed the comet beyond the Moon, which showed that the heavens were not unchanging after all.
Q 22Edmond Halley used whose theories to show that three comet sightings were one returning comet?
Isaac Newton
Isaac Newton's theory of gravitation let Halley compute comet orbits, even allowing for Jupiter's pull on the comet's path.
Q 23Which three French mathematicians refined the predicted return date of Halley's Comet?
Clairaut, Lalande and Lepaute
Q 14Which amino acid was confirmed in 2009 in comet dust returned to Earth by a NASA sample-return mission?
Glycine
Glycine could have come from handling the spacecraft, so scientists checked its carbon isotopes, which showed it formed in space rather than on Earth.
Q 15What surprising radiation were comets found to emit in 1996?
X-rays
X-rays arise when solar wind ions steal electrons from a comet's gas, a surprise because comets were thought far too cold for such energetic emission.
Q 16Which August meteor shower is debris from Comet Swift-Tuttle?
The Perseids
The Perseids seem to streak out of the constellation Perseus, which gives them their name, as Earth ploughs through the comet's dust each August.
Q 17The Andromedid meteor shower is the remains of which body, which split in two in 1846 and was never seen after 1852?
Biela's Comet
Spectacular showers appeared in 1872 and 1885 when the comet should have returned.
Q 18Which comet broke apart and crashed into Jupiter in July 1994?
Comet Shoemaker-Levy 9
Comet Shoemaker-Levy 9 had been torn apart on a close pass of Jupiter in July 1992, so it struck the planet as a string of separate fragments.
Q 19Which ancient philosopher argued that comets were atmospheric phenomena?
Aristotle
Aristotle reasoned that comets could not be planets because many appear outside the zodiac, so he placed them in the upper atmosphere.
Q 20Giotto saw a comet, probably Halley's, in 1301 and painted it in Padua as which biblical sign?
The Star of Bethlehem
The Star of Bethlehem in Giotto's Adoration of the Magi takes the shape of a comet, and ESA later named its 1986 Halley's Comet probe Giotto in his honour.
Clairaut, Lalande and Lepaute spent six months calculating from morning to night, and the comet reached perihelion on 13 March 1759, a month before their mid-April forecast.
Q 24About how often does Halley's Comet return?
Every 76 years
Every 76 years is only an average, because the pull of Jupiter and Saturn delays or hastens each return.
Q 25Which famous medieval tapestry shows Halley's Comet as a sign in the sky?
The Bayeux Tapestry
The Bayeux Tapestry shows the comet of 1066, which some took as an omen, shortly before William the Conqueror invaded England.
Q 26Which toxic gas found in Halley's tail in 1910 caused panic buying of gas masks and anti-comet pills?
Cyanogen
By then most scholars had long since dismissed comets as omens.
Q 27Which writer was born two weeks after Halley's 1835 perihelion and died the day after its 1910 return?
Mark Twain
Mark Twain said in 1909 that he had come in with Halley's Comet and expected to go out with it, and his prediction came true.
Q 28Who proposed the dirty snowball model of comets in 1950?
Fred Whipple
Fred Whipple also invented the Whipple shield, a thin outer metal skin that shatters incoming particles before they can damage a spacecraft.
Q 29How close did ESA's Giotto probe pass to Halley's nucleus in March 1986?
About 600 km
About 600 km was close enough that planners feared dust would destroy Giotto, and a large particle did knock it off balance seconds before closest approach.
Q 30Which two Soviet probes joined Giotto in the Halley Armada of 1986?
Vega 1 and 2
Vega 1 and 2 first dropped landers and balloons at Venus, then swung on to fly past Halley's Comet.