Space Exploration Quiz
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This space exploration trivia quiz has 95 free questions with answers and covers the missions, machines and people that took humanity off the planet: Sputnik and Gagarin, Mercury, Gemini and Apollo, the Space Shuttle and the ISS, the Mars rovers and the probes now leaving the solar system, and the James Webb telescope. It also has a proper rocket trivia section: the Song-dynasty gunpowder rockets, the Congreve rockets in the US national anthem, Tsiolkovsky's equation, Goddard's 41-foot first flight, the V-2 that reached space in 1944, the 363-foot Saturn V and its thirteen launches, and SpaceX's Falcon 9 landing and reflying its boosters. Difficulty runs from easy to expert and is shown on every question. Every answer has been checked against a primary reference and each question carries its citation.
30 of 95 questions with answers and explanations. Play the quiz
Q 01What is the closest star to Earth, besides the Sun?
Proxima Centauri
Proxima Centauri is the dimmest of the three stars in the Alpha Centauri system: no star lies nearer to the Sun, yet this red dwarf is too faint to see with the naked eye.
Q 02Which test for planethood did the former ninth planet fail in 2006?
Clearing its orbit
Clearing its orbit: the demoted world shares its zone with swarms of icy bodies, and the 2005 discovery of Eris, a rival of similar size, pushed astronomers to settle the definition.
Q 03As of 2025, which planet had overtaken Jupiter as the one with the most confirmed moons?
Saturn
Saturn pulled far ahead when astronomers stacked hours of telescope images to pick out faint, distant moons; 128 confirmed in March 2025 lifted its total to 274.
Q 04What is the point of no return around a black hole called?
Event horizon
Past the event horizon, the speed needed to escape exceeds the speed of light, the fastest anything can travel, so whatever crosses it can never come back out.
Q 05Approximately how long does it take sunlight to reach Earth?
About 8 minutes
About 8 minutes: sunlight needs roughly 8 minutes 20 seconds to cross the 150 million km to Earth, so we always see the Sun as it was that long ago.
Q 06Which space telescope, launched on Christmas Day 2021, observes in the infrared from 1.5 million km beyond Earth?
James Webb
James Webb's 6.5-metre gold-coated mirror was too wide for any rocket, so it launched folded up and unfolded itself in space.
Q 07What type of galaxy is the Milky Way?
Barred spiral
Barred spiral: because we sit inside the Milky Way's dusty disc, the long bar of stars across its centre was only mapped convincingly in 2005, by an infrared space telescope.
Q 08Which planet has the highest surface temperature in our solar system?
Venus
Venus has the highest surface temperature at about 465°C (867°F), hot enough to melt lead. Despite being farther from the Sun than Mercury, Venus's thick CO2 atmosphere creates an extreme greenhouse effect that traps heat.
Q 09What was the name of the first artificial satellite launched into space?
Sputnik 1
Sputnik 1, a beeping metal sphere launched by the Soviet Union on 4 October 1957, came as a shock to Americans and set off the Space Race.
Q 10The most extensive planetary ring system in the Solar System is made almost entirely of what?
Water ice
Water ice makes up nearly all of Saturn's rings: billions of chunks, from dust grains to house-sized blocks, thought to be the wreckage of comets or moons torn apart by the planet's gravity.
Q 11Who was the first woman to travel to space?
Valentina Tereshkova
Valentina Tereshkova, a textile-factory worker and amateur skydiver, orbited Earth 48 times in June 1963, logging more flight time than every American astronaut before her combined.
Q 12What is a light-year a measure of?
Distance
Distance: a light-year is how far light travels in one year, about 6 trillion miles, so the 'year' in the name fools many people into thinking it measures time.
Q 13Which rover landed in Mars's Jezero Crater in February 2021?
Perseverance
Perseverance was sent to Jezero Crater because it once held a lake and a river delta, a promising place to hunt for signs of ancient microbial life.
Q 21Which of Jupiter's four large moons is the likeliest candidate for harboring extraterrestrial life?
Europa
Europa is considered one of the most promising places to search for life beyond Earth. It has a subsurface ocean of liquid water beneath its icy crust that may contain more water than all of Earth's oceans combined.
Q 22Approximately how old is the universe?
13.8 billion years
13.8 billion years comes from running the universe's measured expansion backwards to the moment everything was packed together, a figure refined by the Planck space telescope.
Q 23Which galaxy, the nearest large neighbour of the Milky Way, is visible to the naked eye on dark nights?
Andromeda
Q 14What is the tallest known volcano in the solar system?
Olympus Mons
Olympus Mons, about 600 km wide, likely grew so huge because Mars has no moving crustal plates, so lava kept piling up over one hot spot.
Q 15Which moon in our solar system is the only one known to have a dense atmosphere?
Titan
Titan's atmosphere is thicker than Earth's, and its orange haze hides the surface from ordinary cameras; in 2005 the Huygens probe parachuted down through it to the ground.
Q 16Roughly how long does the International Space Station take to circle Earth once?
90 minutes
About 90 minutes: the station laps Earth some 16 times a day, so its crew sees a sunrise or a sunset roughly every 45 minutes.
Q 17What was the first animal to orbit the Earth?
Laika the dog
Laika the dog, a stray from the streets of Moscow, rode the second Soviet satellite into orbit in November 1957; with no way to bring her home, she died of overheating within hours.
Q 18Which planet has an axial tilt of about 98 degrees, so it rotates nearly on its side?
Uranus
Uranus spins tipped over at about 98 degrees, possibly knocked sideways long ago by a collision with an Earth-sized body, so each pole in turn points almost straight at the Sun.
Q 19In 2019, linked radio telescopes worldwide produced the first direct image of what?
Black hole
A black hole: eight radio observatories around the world were linked into one Earth-sized telescope to capture the glowing ring around the dark heart of galaxy M87.
Q 20What causes the seasons on Earth?
The tilt of its rotation axis
The tilt of its rotation axis leans each hemisphere toward the Sun in turn; Earth is actually nearest the Sun in January, in the depths of northern winter.
Andromeda's light takes about 2.5 million years to reach us, so the faint smudge skywatchers see tonight set out long before modern humans existed.
Q 24Which astronomer used a telescope in 1610 to discover four of Jupiter's moons?
Galileo Galilei
Galileo Galilei's four moons were the first bodies seen circling another planet, a blow to the old belief that everything in the heavens orbits Earth.
Q 25On slow-spinning Mercury, one sunrise-to-sunrise day lasts how long compared with its year?
Twice as long
Twice as long: Mercury takes about 59 Earth days to turn once but only 88 to circle the Sun, so one sunrise-to-sunrise day lasts about 176 Earth days, two of its years.
Q 26What is the approximate speed of light?
186,000 miles per second
186,000 miles per second is fast enough to circle Earth seven and a half times in a second, yet starlight still takes years to arrive, so we see the stars as they were in the past.
Q 27What is the disc of icy bodies extending from roughly 30 to 50 AU from the Sun called?
Kuiper Belt
The Kuiper Belt was only an idea, floated in various forms for decades, until 1992, when astronomers David Jewitt and Jane Luu finally spotted a small icy body out there.
Q 28Which spacecraft became the first human-made object to enter interstellar space?
Voyager 1
Voyager 1 launched 16 days after its twin but took a faster route, overtook it within months, and crossed into interstellar space in August 2012, six years ahead of Voyager 2.
Q 29Which U.S. president challenged the nation to land a man on the Moon before the decade was out?
John F. Kennedy
John F. Kennedy set the goal before Congress on 25 May 1961, when America's entire experience of human spaceflight was a single 15-minute hop and no American had yet orbited Earth.
Q 30Which company became the first private firm to launch astronauts into orbit, in May 2020?
SpaceX
SpaceX's Crew Dragon, on a test flight called Demo-2, carried Doug Hurley and Bob Behnken and ended a nine-year gap in which no astronauts had launched to orbit from American soil.