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50 free Edwin Hubble trivia questions with answers — science & nature quiz, new questions added Aug 2026.
Edwin Hubble was a high-school track star and Big Ten basketball champion who studied law at Oxford to please his dying father, then went to Mount Wilson and proved the universe was vastly bigger than the Milky Way. In 1929 he showed that galaxies recede faster the farther away they are, the observation that made Einstein abandon his "biggest blunder". This quiz is about the astronomer, not the space telescope, though the telescope gets a question too. Easy questions ask what he proved about the nebulae, which telescope carries his name and which law bears it. Harder ones want the star type he used as a yardstick, the Harvard rival who opposed him, the newspaper that broke his discovery, his wildly wrong value for the constant, the Belgian priest who got there first, the wartime job that earned him a Legion of Merit, the comet and asteroid he found, why he never got a Nobel Prize and where he is buried, which nobody knows. Every answer was checked against Wikipedia's biography of Edwin Hubble, and each question carries the sentence that supports it. Made for astronomy teachers, students and quiz hosts. Related quizzes: Hubble Space Telescope, Astronomy and Famous Physicists.
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Q 01What did Hubble prove about many objects that had been classified as "nebulae"?
They were galaxies beyond the Milky Way
Hubble's 1923–24 distance measurements put the spiral nebulae far outside the Milky Way, proving they were galaxies beyond the Milky Way, a result announced on 1 January 1925.
Q 02What does Hubble's 1929 finding that galaxies recede faster with distance imply about the universe?
It is expanding
A recession velocity proportional to distance means the universe is expanding uniformly; the relation, published in 1929 from two dozen galaxies' redshifts, became known as Hubble's law.
Q 03Which pulsating stars, whose period-luminosity relation Henrietta Leavitt found, did Hubble use to measure distances?
Cepheid variables
Cepheid variables pulse with a period tied to their true luminosity, so comparing observed brightness with luminosity yields distance; Hubble found Cepheids in spiral nebulae with the Mount Wilson reflector.
Q 04In which Missouri town, home to a model of the space telescope, was Hubble born in 1889?
Marshfield
Hubble was born in Marshfield, Missouri, on 20 November 1889; the Webster County seat displays a quarter-scale replica of the Hubble Space Telescope on its courthouse lawn.
Q 05What was the profession of Hubble's father, John Powell Hubble?
Insurance executive
John Powell Hubble worked as an insurance executive, a job that moved the family from Missouri to Illinois in 1900; he died in 1913 while Edwin was at Oxford.
Q 06What was the only school subject in which the young Hubble did not earn good grades?
Spelling
Spelling was the one subject that escaped him; otherwise the young Hubble earned good grades while being better known for athletics, playing baseball and football and running track.
Q 07For which university did Hubble play on a conference-champion basketball team?
Chicago
Hubble played for the University of Chicago, whose basketball team won Western Conference (later Big Ten) championships during his years there, 1906 to 1910.
Q 08For which future Nobel-winning physicist did Hubble work as a student laboratory assistant?
Robert Millikan
Robert Millikan, later the 1923 physics laureate for measuring the electron's charge, employed Hubble as a student laboratory assistant during his undergraduate years.
Q 09What did Hubble study at Oxford as a Rhodes Scholar, keeping a promise to his dying father?
Jurisprudence
Hubble read jurisprudence at Queen's College, Oxford, from 1910 to 1913, honouring his father's wish that he study law, though he never practised.
Q 10What did Hubble do for a year at New Albany High School in Indiana after returning from Oxford?
Taught Spanish, physics and maths and coached basketball
At New Albany High School in 1913–14 Hubble taught Spanish, physics and maths and coached basketball, then left to pursue a doctorate in astronomy.
Q 11Where did Hubble earn his 1917 PhD with a dissertation on faint nebulae?
Yerkes Observatory
Hubble wrote his dissertation, Photographic Investigations of Faint Nebulae, at Yerkes Observatory in Williams Bay, Wisconsin, whose 40-inch refractor was the largest of its type ever put to regular use.
Q 12What rank did Hubble reach in the US Army's 86th Division during the First World War?
Major
Hubble enlisted in 1917 after hurrying through his doctorate and rose to major in the 86th Division, which reached France in 1918 but was broken up for replacements and never fought.
Q 13Who offered Hubble a staff position at Mount Wilson Observatory in 1919?
George Ellery Hale
Q 21What value did Hubble's measurements on 46 galaxies give for the Hubble constant?
500 km/s/Mpc
Hubble's 1929 analysis of 46 galaxies gave a constant near 500 km/s/Mpc, far too high because his distance scale was badly underestimated; later measurements put it near 70.
Q 22Which Belgian priest-physicist predicted the redshift-distance law two years before Hubble?
Georges Lemaître
Georges Lemaître derived the velocity–distance relation in a 1927 paper in a Belgian journal; a 2011 study by Mario Livio showed Lemaître himself trimmed the later English translation.
Q 23Which word did Hubble attach to the galaxies' velocities in a letter to de Sitter?
"Apparent"
George Ellery Hale, founder and director of Mount Wilson Observatory, hired Hubble in 1919 after his discharge from the army that summer.
Q 14Which instrument, then the world's largest of its kind, was newly completed when Hubble arrived at Mount Wilson?
The 100-inch Hooker Telescope
The 100-inch Hooker Telescope on Mount Wilson, completed in 1917 and funded by John D. Hooker, was the world's largest for three decades; Hubble used it for his nebula distances.
Q 15Which two nebulae did Hubble's 1924 variable-star observations prove were separate galaxies?
Andromeda and Triangulum
Hubble's variable-star distances put the Andromeda and Triangulum nebulae (M31 and M33) nearly a million light-years away, far beyond any estimate of the Milky Way's size.
Q 16Who argued in the 1920 Great Debate that the spiral nebulae lay within the Milky Way?
Harlow Shapley
Harlow Shapley, later director of Harvard College Observatory, held in the 1920 debate with Heber Curtis that the spirals were nearby; Hubble's 1924 letter, he said, 'destroyed my universe'.
Q 17In which newspaper were Hubble's findings on the nebulae first published, on November 23, 1924?
The New York Times
The New York Times reported Hubble's discovery on 23 November 1924, weeks before he presented it to the American Astronomical Society on 1 January 1925; the full paper followed in 1929.
Q 18What is the astronomer's system for classifying galaxies by their photographic appearance called?
The Hubble sequence
The Hubble sequence, introduced in 1926, sorts galaxies into ellipticals, spirals and barred spirals and is usually drawn as a tuning-fork diagram.
Q 19By roughly what factor were Hubble's estimated galaxy distances later found to be too small?
Up to about 7
Hubble's distances were too small by up to about 7 times, because he mixed two classes of pulsating variables and took bright gas clouds for stars; relative distances held nonetheless.
Q 20Which two astronomers' redshift measurements did Hubble combine with his distances?
Vesto Slipher and Milton Humason
Vesto Slipher at Lowell had measured most of the nebular redshifts from 1912 onward, and Milton Humason at Mount Wilson added fainter galaxies; Hubble paired these velocities with his distances.
Hubble wrote to de Sitter that he used the term 'apparent' velocities to emphasise the empirical features of the correlation, leaving interpretation to those competent to discuss it.
Q 24What did Einstein reportedly call the cosmological constant he'd added to keep the universe static?
"The biggest blunder of my life"
Einstein reportedly called the constant 'the biggest blunder of my life', a remark recorded by George Gamow; after seeing Hubble's redshift data he abandoned the term.
Q 25In which year did Einstein visit Mount Wilson, meet Hubble and say the visit 'changed his mind'?
1931
Einstein spent early 1931 at Caltech and Mount Wilson, where he toured the observatory with Hubble and publicly accepted that the universe was expanding.
Q 26Which asteroid did Hubble discover on August 30, 1935?
1373 Cincinnati
Hubble's only asteroid find, 1373 Cincinnati, turned up on a Mount Wilson plate on 30 August 1935 and was named for the Cincinnati Observatory.
Q 27What was the title of Hubble's 1936 book explaining his approach to extragalactic astronomy?
The Realm of the Nebulae
The Realm of the Nebulae, published by Yale in 1936 from his Silliman lectures, set out Hubble's classification of galaxies and his distance and redshift work.
Q 28Which assistant of Hubble's carried on his cosmology programme after his death in 1953?
Allan Sandage
Allan Sandage, Hubble's last assistant, inherited his observing programme after 1953 and in 1958 revised the expansion rate down to about 75 km/s/Mpc.
Q 29What did Hubble surprisingly tell the AAAS in December 1941 that a six-year Mount Wilson survey showed?
The results did not support the expanding universe
His own constant would have made the Big Bang only 2 billion years old, younger than the Earth.
Q 30Where did Hubble work as a civilian during the Second World War, heading the External Ballistics Branch?
Aberdeen Proving Ground, Maryland
At Aberdeen Proving Ground in Maryland, Hubble headed the External Ballistics Branch of the Ballistics Research Laboratory from 1942, devising a high-speed clock camera and earning the Legion of Merit in 1946.