Astrophysics
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50 free Astrophysics trivia questions with answers — science & nature quiz, new questions added Oct 2026.
Astrophysics takes the laws of physics worked out in laboratories on Earth and applies them to everything else: the stars, the galaxies and the universe itself. It explains why stars shine, what is left behind when they die, and how we can know anything at all about objects too distant ever to visit. This quiz covers the core ideas and the people behind them. Expect questions on the life cycles of stars, black holes and other extreme objects, the evidence for the Big Bang and an expanding universe, the tools astronomers use to weigh and measure the cosmos, and the physicists whose discoveries changed the picture, sometimes against fierce resistance. The questions run from easy openers for anyone who has watched a space documentary to harder ones for physics students and keen stargazers. Every answer comes with a short explanation, so the quiz works as a study aid for a class or a science club as well as a round for trivia night.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Which rock guitarist earned a PhD in astrophysics from Imperial College London in 2007, some 37 years after starting it?
Brian May
Brian May shelved his thesis on interplanetary dust in 1974, when Queen found international success. He later worked with the science team on NASA's New Horizons mission to Pluto.
Q 02Which element was first spotted in the Sun's light during an 1868 eclipse, years before anyone isolated it on Earth?
Helium
Helium takes its name from helios, the Greek word for the Sun. It was 1895 before the chemist William Ramsay isolated it on Earth, from a uranium mineral.
Q 03What name do astrophysicists give the extreme vertical stretching of an astronaut falling feet first into a black hole?
Spaghettification
Spaghettification happens because gravity pulls far harder on the feet than on the head. Near a small black hole the difference is strong enough to pull a person into a long thin strand.
Q 04Light leaving the Sun's surface crosses about 150 million kilometres of space to reach Earth in roughly how long?
8 minutes
About 8 minutes is all sunlight needs, which means we always see the Sun as it was that long ago. Astronomers describe the distance as roughly 8 light-minutes.
Q 05Astronomers watching the 2017 neutron-star collision GW170817 saw the creation of several Earth masses of which element?
Gold
Gold and platinum amounting to about ten Earth masses formed in the collision, by one estimate. Such mergers are now seen as a main cosmic source of both metals.
Q 06Which physicist, later director of the Los Alamos atomic bomb laboratory, co-wrote a 1939 paper predicting black holes?
Robert Oppenheimer
Robert Oppenheimer and his student Hartland Snyder showed that a heavy enough star must keep collapsing without limit. The name black hole did not catch on until the 1960s.
Q 07IceCube, a detector frozen into a cubic kilometre of ice at the South Pole, was built to catch which elusive particles?
Neutrinos
Neutrinos interact so weakly that about 65 billion from the Sun cross every square centimetre of Earth each second. IceCube records the faint flash when one finally hits the ice.
Q 08After swelling and shedding its outer layers billions of years from now, the Sun will end as which Earth-sized remnant?
White dwarf
A white dwarf packs about a Sun's worth of mass into a ball the size of Earth. The Sun is far too light to explode as a supernova or collapse into a black hole.
Q 09Which unit of distance, equal to about 3.26 light-years, does Han Solo wrongly use as a measure of time?
Parsec
Parsec is a real unit, worth about 31 trillion kilometres. The nearest star beyond the Sun, Proxima Centauri, lies just 1.3 of them away.
Q 10Which Cambridge physicist argued in 1974 that black holes are not truly black but slowly leak radiation and evaporate?
Stephen Hawking
Stephen Hawking's radiation is so feeble that a black hole with the Sun's mass would take far longer than the age of the universe to evaporate.
Q 11The Sun and other stars are made of which state of matter, rare on Earth but seen in lightning and neon signs?
Plasma
Plasma accounts for an estimated 99.9% of the ordinary matter in the universe. It forms when a gas is heated until electrons break free of their atoms.
Q 12Which famous equation explains how the Sun's core turns four million tonnes of matter into energy every second?
E = mc²
E = mc² says a tiny amount of mass equals a huge amount of energy, because the speed of light squared is an enormous number. The Sun can keep paying that bill for billions of years.
Q 13Vera Rubin's finding that outer stars in spiral galaxies orbit far too fast was key evidence for the existence of what?
Dark matter
Q 21Which Oxford mathematician shared the 2020 physics Nobel for proving that general relativity demands black holes?
Roger Penrose
Roger Penrose and his father also devised the impossible Penrose triangle and Penrose stairs, which inspired Escher's prints Waterfall and Ascending and Descending.
Q 22The international ITER reactor aims to recreate on Earth which process that makes the Sun and other stars shine?
Nuclear fusion
Nuclear fusion in the Sun's core joins hydrogen nuclei at about 15 million degrees. Hans Bethe won the 1967 Nobel Prize in Physics for working out how stars do it.
Q 23Which phenomenon, heard as a passing siren drops in pitch, lets astronomers clock stars approaching or receding?
Doppler effect
Dark matter seems to make up about 85% of all the matter in the universe. It gives off no light, so astronomers can trace it only through the pull of its gravity.
Q 14Which Northern Irish scientist found the first pulsar as a student in 1967 but was passed over for the Nobel Prize?
Jocelyn Bell Burnell
Jocelyn Bell Burnell's radio pulses were so regular that the source was at first dubbed Little Green Man 1. In 2018 she won a $3 million prize and gave it all away to fund physics students.
Q 15Which Nobel-winning Caltech physicist advised Christopher Nolan on the black hole in the film Interstellar?
Kip Thorne
Kip Thorne's equations drove the film's visual effects, and the images were accurate enough to yield three scientific papers. He shared the 2017 Nobel Prize for detecting gravitational waves.
Q 16The James Webb Space Telescope has to stay below minus 220 °C because it observes mainly which kind of light?
Infrared
Infrared light passes through the dust clouds that hide newborn stars, and it carries the stretched glow of the earliest galaxies. A warm telescope would drown both in its own heat.
Q 17Which astrophysicist took over New York's Hayden Planetarium in 1996 and later hosted Cosmos: A Spacetime Odyssey?
Neil deGrasse Tyson
Neil deGrasse Tyson received hate mail, much of it from children, after his planetarium stopped listing Pluto among the planets. The show revived a 1980 series by Carl Sagan.
Q 18By the Planck satellite's measurements of the oldest light in the cosmos, the universe is roughly how old?
13.8 billion years
13.8 billion years makes the universe about three times as old as the Sun and Earth. Planck's team pinned the figure down to better than one percent.
Q 19Which hypothetical shortcut through spacetime got its name in a 1957 paper co-written by the physicist John Wheeler?
Wormhole
Wormhole tunnels are consistent with general relativity, but nobody knows whether any exist. Keeping one open for a traveller would seem to need exotic matter with negative energy.
Q 20Earth squeezed into a black hole would have which boundary of no return, just 9 millimetres in radius?
Event horizon
The event horizon is not a solid surface, and an astronaut crossing a big black hole's would feel nothing special at that moment. The Sun's would have a radius of about 3 km.
The Doppler effect is named after Christian Doppler, who proposed it in 1842 in a paper about the colours of double stars. It was first tested, on sound, three years later.
Q 24Which outer layer of the Sun, seen as a pale halo during total eclipses, mysteriously exceeds a million degrees?
Corona
The corona is some 200 times hotter than the Sun's visible surface beneath it. Physicists still argue over what heats it.
Q 25Supernova surveys revealed in 1998 that the universe's expansion is speeding up, driven by which mysterious ingredient?
Dark energy
Dark energy accounts for roughly 68% of everything in the universe, yet nobody knows what it is. The discovery won three astronomers the 2011 Nobel Prize in Physics.
Q 26Which astronomer showed in the 1920s that Andromeda lies beyond the Milky Way and that distant galaxies are receding?
Edwin Hubble
Edwin Hubble had studied law at Oxford as a Rhodes Scholar before turning to astronomy. His discoveries came at Mount Wilson's 100-inch telescope, then the world's largest.
Q 27Which British astrophysicist coined the name Big Bang on BBC radio in 1949 for a theory he himself rejected?
Fred Hoyle
Fred Hoyle argued instead for a steady-state universe with no beginning, and went on defending it for decades. He also showed how stars could forge carbon.
Q 28Arno Penzias and Robert Wilson first blamed pigeon droppings for a radio hiss that proved to be which Big Bang relic?
Cosmic microwave background
The cosmic microwave background is light set free about 380,000 years after the Big Bang, now cooled to 2.7 degrees above absolute zero. The find won the pair the 1978 Nobel Prize.
Q 29Which observatory's twin L-shaped detectors in Louisiana and Washington state first caught gravitational waves in 2015?
LIGO
LIGO measures changes in the 4 km gap between its mirrors that are far smaller than the width of a proton. The first signal came from two black holes merging over a billion light-years away.
Q 30The four-million-solar-mass black hole at the centre of the Milky Way is named after which constellation?
Sagittarius
Sagittarius A* is the black hole's full name. The first image of it, released in 2022, took five years of calculations to process.