Mars
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96 free Mars trivia questions with answers — science & nature quiz, new questions added Aug 2026.
50 free Mars trivia questions with answers. Mars has captivated humanity for millennia — from ancient warriors who named it after their god of war to modern scientists searching for signs of life in its rusty soil. From Olympus Mons to Perseverance, from Phobos to potato farms, how much do you really know about our most tantalizing neighbor? These 96 questions will find out.
30 of 96 questions with answers and explanations. Play the quiz
Q 01What gives Mars its distinctive reddish appearance?
Iron oxide (rust) on its surface
Iron oxide (rust) on its surface tints the fine dust that blankets Mars, and winds lift so much of it that even the daytime sky looks hazy and butterscotch-coloured.
Q 02What is the name of the tallest volcano on Mars, and the tallest known volcano in the solar system?
Olympus Mons
Olympus Mons stands more than twice the height of Everest; a big reason is that Mars has no drifting plates, so lava kept piling up over a single hotspot.
Q 03What do mission teams call a Martian day, which runs about 40 minutes longer than a day on Earth?
A sol
A sol lasts 24 hours 39 minutes 35 seconds, so teams working on Mars time start their shifts about 40 minutes later each Earth day and slowly drift around the clock.
Q 04Which canyon system on Mars is long enough to stretch from California to New York?
Valles Marineris
Valles Marineris runs roughly 4,000 km and is thought to have begun as a giant crack in the crust, pulled open as the neighbouring Tharsis volcanic region swelled.
Q 05Mars's mean surface air pressure is roughly what fraction of Earth's sea-level pressure?
About 0.6%
About 0.6% of Earth's sea-level pressure is all the thin Martian air manages, close to the triple point of water, so liquid water on the surface would boil away or freeze almost at once.
Q 06Which spacecraft became the first ever to orbit another planet when it reached Mars in November 1971?
Mariner 9
Mariner 9 beat the Soviet Mars 2 and Mars 3 probes by only weeks, then had to wait out a months-long dust storm before it could send back clear pictures of the surface.
Q 07Which NASA lander recorded more than 1,300 marsquakes between 2018 and 2022?
InSight
InSight placed its seismometer directly on the ground, and the tremors it recorded showed that Mars is still active inside; dust smothering its solar panels finally ended the mission in December 2022.
Q 08What is the approximate surface gravity on Mars compared to Earth?
About 38%
About 38% of Earth's pull means someone who weighs 100 kg here would register about 38 kg on Mars; the weak gravity is also one reason Martian volcanoes could grow so tall.
Q 09What is the primary component of Mars's atmosphere?
Carbon dioxide
Carbon dioxide makes up about 95% of Mars's atmosphere, with a few percent of nitrogen and argon and only traces of oxygen, which is why NASA has tested a device that splits the gas to make breathable oxygen.
Q 10What kind of feature is Hellas Planitia, whose floor holds the lowest point on Mars?
An impact basin
An impact basin about 2,300 km wide, Hellas is so deep that winter air pressure on its floor is about twice the Martian average, enough in principle for liquid water to exist there.
Q 11Which NASA rover landed in 2004 for a 90-day mission and kept working for more than 14 years?
Opportunity
Opportunity drove more than 45 km before a planet-wide dust storm blotted out its solar panels in June 2018; NASA ended the mission in February 2019 after over a thousand recovery commands went unanswered.
Q 12What is the name of the helicopter drone that flew on Mars as part of the Perseverance mission?
Ingenuity
Ingenuity was a small helicopter that made the first powered, controlled flight on another planet on April 19, 2021. Originally designed for 5 flights, it completed 72 flights before its mission ended in January 2024.
Q 13In which Martian crater did the Curiosity rover land in 2012?
Gale Crater
Q 21What did the Curiosity rover photograph in 2012 that showed a stream had once flowed across its landing site?
Rounded pebbles
Rounded pebbles cemented into rock were too big for wind to have carried, so water must have tumbled them smooth; the team judged the stream had been between ankle and hip deep.
Q 22What is the contrast between Mars's low northern plains and cratered southern highlands called?
The Martian dichotomy
The Martian dichotomy is the split between low, smooth northern plains and the heavily cratered southern highlands; one leading idea is that a single giant impact early in Mars's history blasted out the northern lowlands.
Q 23What is the average surface temperature on Mars?
Gale Crater surrounds Mount Sharp, a mountain about 5.5 km high that Curiosity has been climbing for more than a decade; several lines of evidence show the crater once held a lake.
Q 14Which lander, the first to complete a successful mission on Mars, touched down on July 20, 1976?
Viking 1
Viking 1 was meant to land on 4 July 1976, the US bicentennial, but orbital photos showed the chosen site was too rough, so touchdown slipped to 20 July, seven years to the day after Apollo 11's Moon landing.
Q 15What was the name of the small rover carried by the Mars Pathfinder mission in 1997?
Sojourner
Sojourner was named for the abolitionist Sojourner Truth by a 12-year-old who won an essay contest; built to last about a week, the rover kept exploring for nearly three months.
Q 16In which crater did NASA's Perseverance rover land in 2021?
Jezero Crater
Perseverance landed in Jezero Crater on February 18, 2021. Scientists chose this location because it contains an ancient river delta, making it an ideal place to search for signs of past microbial life.
Q 17Which Perseverance experiment made oxygen from the air of Mars?
MOXIE
MOXIE showed that breathable oxygen can be pulled straight out of the thin Martian air, about 122 grams of it in all, a first step toward making air and rocket propellant for future crews.
Q 18Which Mars mission discovered that the planet once had a thicker atmosphere stripped away by solar wind?
MAVEN
MAVEN was the first mission devoted to Mars's upper atmosphere; by measuring how fast gas escapes, it showed that the solar wind stripped away most of the planet's early air and left the cold desert seen today.
Q 19Which twin rovers made up NASA's Mars Exploration Rover mission?
Spirit and Opportunity
Spirit and Opportunity landed on opposite sides of Mars in January 2004; each carried metal from the fallen World Trade Center, shaped into shields for the cables of its rock drill.
Q 20What did NASA's Phoenix lander discover just below the Martian surface in 2008?
Water ice
Water ice gave itself away when dice-sized bright lumps in a trench dug by Phoenix's robotic arm vanished over four days, turning straight from solid to vapour in the thin air.
About -63°C (-81°F)
About -63°C (-81°F) is the commonly quoted average, but the thin air holds so little heat that readings range from about 20°C at the equator at midday down to about -153°C at the poles.
Q 24What kind of ice forms the permanent surface of Mars's southern polar cap?
Dry ice (frozen CO2)
Dry ice (frozen CO2) covers the southern cap all year, whereas in the north it vanishes each summer to expose frozen water; beneath the southern dry ice lies a much thicker layer of frozen water too.
Q 25Roughly how long does Mars take to complete one orbit of the Sun?
About 687 days
About 687 days, nearly two Earth years, because Mars circles farther out and moves more slowly; each of its seasons lasts roughly twice as long as ours.
Q 26Each spring, jets of gas bursting through Mars's south polar ice carve dark, branching channels nicknamed what?
Spiders
Spiders form when spring sunlight warms the ground beneath the seasonal ice: trapped gas builds up, bursts through the slab and scours channels that radiate from each vent, a process seen nowhere on Earth.
Q 27In Babylonian astronomy, the planet Mars was named for which deity?
Nergal
Nergal was the Mesopotamian god of war, plague and death, so the blood-red planet was tied to bloodshed long before the Romans named it for their own war god.
Q 28The names of Mars's two moons come from Greek words meaning what?
Fear and Dread
Fear and Dread are what Phobos and Deimos mean; in Greek myth the pair are usually the sons of the war god and go into battle at his side.
Q 29Who discovered Mars's two moons in 1877?
Asaph Hall
Asaph Hall was ready to abandon the hunt until his wife, Angeline Stickney, urged him on; he found both moons within a week in August 1877, and the largest crater on Phobos is now called Stickney.
Q 30Which astronomer built an Arizona observatory to map 'canals' on Mars that did not exist?
Percival Lowell
Percival Lowell took Schiaparelli's 'canali', Italian for channels, to be canals dug by an intelligent civilization; the observatory he founded to study them later discovered Pluto.