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60 free Dark Matter trivia questions with answers — science & nature quiz, new questions added Aug 2026.
This dark matter trivia quiz covers the invisible stuff that makes up about 85 percent of the matter in the universe and still has never been detected in a laboratory. The easy questions are the ones any science fan can answer: what dark matter does not interact with, how much of the cosmos it makes up, and how it differs from dark energy. From there the set moves through the history: Lord Kelvin's dark bodies, Fritz Zwicky's dunkle Materie in the Coma Cluster, Vera Rubin and Kent Ford's flat rotation curves, and the 1974 papers from Princeton and Tartu that made galactic halos mainstream. The harder end is for physics buffs: the Bullet Cluster and why it embarrasses modified gravity, cold versus hot dark matter and free streaming length, why neutrinos cannot be the answer, WIMPs and the liquid xenon detectors hunting them, the axion that Frank Wilczek named after a laundry detergent, MACHOs, MOND, primordial black holes, the Lambda-CDM percentages, and the observatory in Chile that carries Rubin's name. Every answer was checked against encyclopaedia entries for dark matter, its discoverers, its candidate particles and its rival theories before publishing, and the supporting sentence is stored with each question. If you enjoy this one, try our Astronomy, Physics and Space quizzes next.
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Q 01Dark matter is so called because it does not interact with what?
Electromagnetic radiation such as light
Its existence is inferred entirely from gravitational effects.
Q 02In the standard Lambda-CDM model, roughly what share of the universe's mass-energy is dark matter?
27%
Ordinary matter is about 5 percent and dark energy about 68 percent.
Q 03Dark matter makes up roughly what fraction of the total matter (not energy) in the universe?
85%
Ordinary atoms account for the remaining 15 percent or so.
Q 04According to the article, all the dark matter out to Neptune's orbit would weigh about as much as what?
A large asteroid
Its density in the Solar System is far lower than that of ordinary matter.
Q 05Which physicist speculated in 1884 that many stars near the Sun might be dark bodies?
Lord Kelvin
He was estimating the density of stars from their velocity dispersion.
Q 06Which French mathematician used the term matière obscure in 1906?
Henri Poincaré
He wrongly concluded there must be less of it than visible matter.
Q 07Fritz Zwicky applied the virial theorem to which galaxy cluster in 1933?
Coma
He estimated the cluster had about 400 times more mass than could be seen.
Q 08Why were Zwicky's 1933 mass estimates off by more than an order of magnitude?
He used an obsolete Hubble constant
Even so, he correctly concluded that most of the gravitating matter was dark.
Q 09In which city was Fritz Zwicky born?
Varna, Bulgaria
His Swiss father was an industrialist there and served as Norwegian consul.
Q 10Which astronomical term did Zwicky coin while developing the idea of neutron stars?
Supernova
He proposed them as giant explosions at the end of a star's life.
Q 11What was Zwicky's famous insult for people he disliked?
Spherical bastards
He explained they were bastards no matter which way you looked at them.
Q 12Which instrument-maker collaborated with Vera Rubin on her 1970s rotation-curve measurements?
Kent Ford
They used his image-tube spectrograph on edge-on spiral galaxies.
Q 13What did Rubin observe about the outermost parts of spiral galaxies?
They move as fast as material near the centre
Kepler's laws predict speeds should fall with distance, as in the Solar System.
Q 21Which colliding pair of galaxy clusters shows its lensing mass sitting apart from its visible gas?
The Bullet Cluster
Hot gas was slowed by the collision while the dark matter sailed straight through.
Q 22Which type of theory does the colliding-cluster evidence make particularly difficult to defend?
Modified gravity
Modified gravity generally predicts lensing around the visible matter, not beside it.
Q 23Galaxy cluster masses measured three ways agree dark matter outweighs visible matter by roughly what ratio?
5 to 1
The methods are galaxy velocities, X-ray gas temperature and gravitational lensing.
Q 14Rubin became the first woman permitted to observe at which observatory in 1965?
Palomar
She had joined the Carnegie Institution of Washington that same year.
Q 15Under which famous physicist did Rubin earn her PhD at Georgetown in 1954?
George Gamow
She had turned down Harvard to follow her husband to Cornell.
Q 16Which honour is Rubin widely argued to have been unjustly denied?
The Nobel Prize
She did receive the National Medal of Science and the RAS Gold Medal.
Q 17The Vera C. Rubin Observatory, named in her honour, is located in which country?
Chile
It sits on Cerro Pachón, beside the Gemini South telescope.
Q 18What record does the Rubin Observatory's 3.2-gigapixel imaging instrument hold?
It is the largest camera ever built
The 3.2-gigapixel CCD camera images the whole southern sky every few days.
Q 19Two 1974 papers argued galaxies sit in halos of unseen matter. Which cities were the teams in?
Princeton and Tartu
The Estonian team was led by Jaan Einasto; Jim Peebles was on the American one.
Q 20Radio astronomers traced galaxy rotation far beyond the visible stars by mapping which emission?
The 21 cm line of atomic hydrogen
Rotation curves were traced to 30 kiloparsecs by 1975, far past the optical disk.
Q 24What does 'cold' mean when cosmologists classify the unseen mass as cold rather than hot?
Its particles moved slowly in the early cosmos
The categories refer to free streaming length, not actual temperature.
Q 25Why can neutrinos not make up the bulk of the universe's missing mass?
They move too fast, so they count as hot dark matter
Hot dark matter would have formed superclusters first, but galaxies formed first.
Q 26What does the acronym WIMP stand for?
Weakly interacting massive particle
WIMPs are expected to interact via gravity and a force no stronger than the weak nuclear force.
Q 27Which substance fills the detectors of leading WIMP-hunting experiments such as LUX, PandaX and LZ?
Liquid xenon
All have so far reported null results across the GeV to TeV mass range.
Q 28What is the 'fog' or 'floor' that the LZ experiment entered in 2025?
An irreducible background of solar neutrino signals
LZ detected boron-8 solar neutrinos scattering off nuclei in the detector.
Q 29Which theory's failure to appear at the Large Hadron Collider has squeezed the case for WIMPs?
Supersymmetry
The null results have shifted attention toward axions and macroscopic candidates.
Q 30Frank Wilczek named the axion after what?
A brand of laundry detergent
Steven Weinberg had wanted to call it the higglet.