100+ Planet Trivia Questions and Answers

Planets float around our solar system, light up the night sky, and hold a world of knowledge and wonder that we have barely scratched the surface of. Whether it’s gas giant planets, moons, or terrestrial planets that rotate around our sun, our solar systems knowledge can easily be challenged at any time. So that’s what we want to do with this planet trivia collection.


Planet Trivia

The massive behemoths that float around space in our system and across the Milky Way galaxy hold worlds of information and knowledge. So let’s look at some of the most well-known planet trivia that could fascinate you.

  • The surface temperature on Mars can reach up to -220 degrees F at night during the wintertime.
  • Jupiter’s largest moon is about 4.503 billion years old.
  • The recognized dwarf planets in our solar system include Pluto, Eris, Ceres, Makemake, and Haumea.
  • The largest planet ever discovered is ROXs 42Bb, which is 2.5 times bigger than Jupiter.

Planet Trivia Questions and Answers

Do you want to see for yourself how much planet trivia you know? Try out this planets and solar system quiz and see how many you answer right.

Click on the blurred area to reveal the answer.

Test it out. Click here to reveal the answer 👉 Awesome! You’re ready

What three planets are closest to the Sun?â–¶ Mercury, Venus & Earth
What planet in our solar system has the longest day?â–¶ Venus (243 Earth days)
Which planet in our solar system spins the fastest?â–¶ Jupiter, it rotates once on average in just under 10 hours.
Which planet has the most moons?â–¶ Jupiter
Of the four rocky planets in our solar system, which is the largest and most dense?â–¶ Earth
What’s the oldest planet in our solar system?â–¶ Jupiter
What’s the second smallest planet in our solar system?â–¶ Mars
What’s the brightest planet in earth’s night sky?â–¶ Venus
What are the terrestrial planets in our solar system?â–¶ Earth, Mars, Mercury and Venus
In 1781, what was the first planet to be discovered using the telescope?â–¶ Uranus
What is the hottest planet in our solar system?â–¶ Venus
Callisto is the name of a moon orbiting what planet in our solar system?â–¶ Jupiter
Curiosity is a car-sized rover that was launched by NASA in 2011 to explore which planet?â–¶ Mars
What planet in our solar system has the most gravity?â–¶ Jupiter
Which planet is furthest from the sun?â–¶ Neptune
How many planets in our solar system have moons?â–¶ Six
Which planet in our solar system has the most oxygen?â–¶ Earth
Ceres is a dwarf planet that lies between the orbits of which two planets in our solar system?â–¶ Mars & Jupiter
Titan, Enceladus, Mimas & Iapetus are just some of the moons orbiting which planet?â–¶ Saturn
Which planet in our solar system has an axis that is tilted by 98 degrees?â–¶ Uranus
The Great Red Spot is a gigantic storm located on which planet in our solar system?â–¶ Jupiter
In our solar system which two planets are known as ice giants?â–¶ Uranus and Neptune
In our solar system, which planet has the shortest day?â–¶ Jupiter
Where did a robot named Spirit remain operational over 2000 sols past its planned 90-sol mission?â–¶ Mars
Ganymede, the largest moon in our solar system, belongs to which planet?â–¶ Jupiter
Which planet’s moons are nearly all named after Shakespearean characters?â–¶ Uranus
How many planets in our solar system are not named after a god or goddess?â–¶ One, Earth
Named for the fleet-footed Roman messenger god, which planet has the shortest orbit around the sun?â–¶ Mercury (87.97 days)
Which is the largest of Mars’ two moons?â–¶ Phobos
What is the name of the closest planet to the sun?â–¶ Mercury
What is the largest planet in the solar system?â–¶ Jupiter
What is the smallest planet in the solar system?â–¶ Mercury
What is the most distant planet visible to the naked eye?â–¶ Saturn
Which planet has the most moons in the solar system?â–¶ Jupiter
What is the only planet known to have active volcanoes besides Earth?â–¶ Venus
Which planet has the longest day in the solar system?â–¶ Venus
Which planet is often called the Red Planet?â–¶ Mars
Which planet is known for having a hexagonal shaped storm on its north pole?â–¶ Saturn
Which planet has the largest temperature variations in the solar system?â–¶ Mercury
What is the name of the largest volcano in the solar system, located on Mars?â–¶ Olympus Mons
What is the name of the largest canyon in the solar system, located on Mars?â–¶ Valles Marineris
What is the name of the only planet in the solar system that rotates clockwise?â–¶ Venus
Which planet has the highest mountain in the solar system, named Olympus Mons?â–¶ Mars
Which planet has the shortest year in the solar system, taking only 88 Earth days to complete one orbit around the sun?â–¶ Mercury
Which planet has the most eccentric orbit of all planets in the solar system?â–¶ Pluto
What is the name of the Great Dark Spot, a storm in the atmosphere of Neptune?â–¶ Great Dark Spot
Which planet has the most complex ring system in the solar system?â–¶ Saturn
Which planet has the highest density in the solar system?â–¶ Earth
What is the name of the largest moon in the solar system, which orbits Jupiter?â–¶ Ganymede
How many exoplanets have been discovered so far?â–¶ 5,307
What is the name of the first exoplanet ever discovered?â–¶ 51 Pegasi b
Which exoplanet has the shortest known year?â–¶ PSR JK2-137b
What is the name of the first potentially habitable exoplanet discovered?â–¶ Gliese 581g
Which exoplanet has the longest known year?â–¶ Kepler-438b
Which exoplanet has the highest known surface temperature?â–¶ KELT-9b
What is the name of the exoplanet with the shortest known orbital period?â–¶ K2-137b
Which exoplanet has the highest known mass?â–¶ HR 2562 b
What is the name of the first exoplanet discovered by NASA’s TESS mission?â–¶ Pi Mensae c
Which exoplanet is the most Earth-like in terms of its size and temperature?â–¶ Kepler-438b
What is the name of the exoplanet with the longest known day?▶ β Pictoris b
Which exoplanet has the highest known density?â–¶ Kepler-10b
What is the name of the exoplanet with the longest known night?â–¶ TrES-2b
Which exoplanet is the closest to Earth in terms of its distance from its host star?â–¶ Proxima Centauri b
What is the name of the exoplanet with the shortest known distance from its host star?â–¶ WASP-189b
Which exoplanet has the largest known radius?â–¶ WASP-107b
What is the name of the exoplanet with the longest known transit duration?â–¶ Kepler-421b
Which exoplanet has the most eccentric orbit?â–¶ HD 20782 b
What is the name of the first exoplanet discovered by the transit method?â–¶ HD 209458 b
Which exoplanet has the highest known surface gravity?â–¶ OGLE-2016-BLG-1195Lb
Who is credited with discovering the planet Uranus?â–¶ William Herschel
What famous astronomer was the first person to observe Saturn’s rings?â–¶ Galileo Galilei
Who discovered the dwarf planet Pluto?â–¶ Clyde Tombaugh
What famous astronomer was the first person to observe the planet Venus in detail?â–¶ Galileo Galilei
Who is known for discovering the four largest moons of Jupiter?â–¶ Galileo Galilei
What astronomer first theorized the existence of the planet Neptune?â–¶ John Couch Adams
What astronomer is credited with discovering the planet Uranus?â–¶ William Herschel
Who used the name Mars to call their god of war?â–¶ Ancient Romans
What famous astronomer was the first person to observe the planet Mercury in detail?â–¶ Galileo Galilei
Who is known for discovering the three largest moons of Saturn?â–¶ Giovanni Domenico Cassini
What astronomer is known for discovering the asteroid Ceres, which was once classified as a planet?â–¶ Giuseppe Piazzi
Who discovered the planet Neptune?â–¶ Urbain Le Verrier
What astronomer was the first to observe the planet Uranus and suggest that it was a new planet?â–¶ William Herschel
Who is credited with discovering the first exoplanet?â–¶ Alex Wolszczan
What astronomer is known for discovering the dwarf planet Haumea?â–¶ Jose Luis Ortiz Moreno
Who discovered the planet Venus?â–¶ Ancient astronomers
What astronomer is credited with discovering the planet Neptune?â–¶ Urbain Le Verrier
Who is known for discovering the four largest moons of Saturn?â–¶ Giovanni Domenico Cassini
What astronomer is known for discovering the dwarf planet Makemake?â–¶ Michael E. Brown
Who discovered the planet Jupiter?â–¶ Galileo Galilei
What famous astronomer was the first person to observe the planet Mars in detail?â–¶ Johannes Kepler
Who is credited with discovering the dwarf planet Eris?â–¶ Mike Brown
What astronomer first theorized the existence of the planet Pluto?â–¶ Percival Lowell
The god of Roman mythology often related to harvest is named after what planet?â–¶ Saturn

About the Author

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Tim majored in Humanities with a bachelor in English and Theatre at New York State University. He lectured on entertainment business studies for three years at Plymouth College.

Tim has been a trivia host in his current hometown of Pittsburgh for the past two years. He enjoys hanging out with people who love trivia just as much as he does.

His friends call him the Question Master.