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60 free Comets trivia questions with answers — science & nature quiz, new questions added Aug 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 60 questions with answers and explanations. Play the quiz
Q 01What are comet nuclei mostly made of?
Loose ice, dust and small rocky particles
Fred Whipple's 1950 dirty snowball model was later refined to icy dirtball after Deep Impact.
Q 02What is the huge, thin atmosphere that surrounds a comet's nucleus called?
The coma
It can grow up to 15 times Earth's diameter, and mostly consists of water and dust.
Q 03In which direction does a comet's ion tail point?
Directly away from the Sun
Radiation pressure and the solar wind push the tail outward whether the comet is approaching or leaving.
Q 04What is the release of gases from a comet as it warms near the Sun called?
Outgassing
It produces the coma and, sometimes, the tail.
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 short-period comets originate?
The Kuiper belt and scattered disc
Long-period comets are thought to come from the far more distant, spherical Oort cloud.
Q 07The Oort cloud is named after an astronomer from which country?
Netherlands
Jan Oort revived the idea in 1950 to resolve a paradox about where comets come from.
Q 08Roughly how many comet-like bodies are thought to sit in the Oort cloud?
About a trillion
Only 4,584 comets were actually known as of November 2021.
Q 09Bodies with orbital periods under 200 years are known as what kind of comet?
Periodic or short-period
Their aphelia usually lie out among the giant planets; Halley's is just beyond Neptune.
Q 10Traditional Jupiter-family comets have orbital periods of less than how many years?
20
They also have low inclinations to the ecliptic, up to 30 degrees; Halley-type comets run 20 to 200 years.
Q 11Roughly what fraction of long-period comets are ejected from the Solar System on their first pass by the Sun?
Half
The planets' gravity does the flinging.
Q 12Which was the first detected interstellar comet, found by a Crimean amateur in 2019?
2I/Borisov
ʻOumuamua showed no optical cometary activity; Borisov clearly had a coma.
Q 13How reflective did Giotto find the nucleus of Halley's Comet to be?
About 4 percent
That makes comet nuclei darker than asphalt, which reflects seven percent.
Which amino acid was confirmed in 2009 in comet dust returned to Earth by a NASA sample-return mission?
Q 21Which ancient philosopher argued that comets were atmospheric phenomena?
Aristotle
Seneca the Younger questioned his logic in the 1st century CE.
Q 22In Giotto's 1301 Adoration of the Magi, the first accurate painting of a comet, what does the comet stand in for?
The Star of Bethlehem
ESA later named its Halley probe after the painter.
Q 23Who used the parallax of the Great Comet of 1577 to show comets lie beyond Earth's atmosphere?
Tycho Brahe
He and Michael Maestlin found the comet must be at least four times farther than the Moon.
Glycine
The samples came from the coma of Comet Wild 2 and landed on Earth in 2006.
Q 15Comet 17P/Holmes briefly grew a coma larger than what after an outburst in 2007?
The Sun
The Great Comet of 1811 also had a coma roughly the diameter of the Sun.
Q 16What surprising radiation were comets found to emit in 1996?
X-rays
They come from charge exchange when solar wind ions steal electrons from cometary atoms.
Q 17Which meteor shower, peaking around 9 to 13 August, is debris from Comet Swift-Tuttle?
The Perseids
Earth crosses the trail of dust the comet left behind.
Q 18The 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 19Which comet broke apart and crashed into Jupiter over six days in July 1994?
Shoemaker-Levy 9
It was the first collision between two Solar System objects ever observed.
Q 20At roughly what speed did the fragments of the 1994 comet hit Jupiter?
60 km/s
That is Jupiter's escape velocity, about 216,000 kilometres per hour.
Q 24Newton used which year's great comet in the Principia to show how to fit a parabolic orbit?
1680
The Great Comet of 1680, also called Kirch's Comet, was the first discovered by telescope.
Q 25Which three earlier apparitions did Halley identify in 1705 as one returning comet?
1531, 1607 and 1682
He predicted its return in 1758-59, and it duly appeared.
Q 26Which three French mathematicians refined the predicted return date of Halley's Comet?
Clairaut, Lalande and Lepaute
Nicole-Reine Lepaute was one of the few women doing such calculations at the time.
Q 27About how often does Halley's Comet return?
Every 76 years
The period varies between 72 and 80 years; the next apparition is in mid-2061.
Q 28Halley's Comet appears on which famous embroidery, described in its captions as a star?
The Bayeux Tapestry
It records the comet's 1066 apparition before the Battle of Hastings.
Q 29Which 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 30Which writer was born two weeks after Halley's 1835 perihelion and died the day after its 1910 return?
Mark Twain
He had predicted he would go out with the comet.