Hi, space nerds! Welcome to your new favorite trivia list. We’ve put together a list of 77 challenging and fun planet-related fun facts for you to use at your next trivia night.
With so many facets of our solar system yet to be discovered, it’s impossible to know everything there is to know about the planets. However, if you study this list, you’re 77 steps closer to knowing all there is to know about our galactic neighbors (and the planet we live on, too!).
Keep scrolling to get to our fun planet trivia questions.
1. Question: What was the first NASA mission sent to orbit Mercury?
2. Question: Which of the following isn’t a moon of Jupiter: Ganymede, Galatea, Europa, Callisto? (Bonus: which planet does the outlier orbit?)
Answer: Galatea. Bonus: It orbits Neptune.
3. Question: How many ring arcs does Neptune have?
Answer: Neptune has four faint ring arcs.
4. Question: As of January 2023, which two NASA rovers are currently exploring the surface of Mars?
Answer: Curiosity and Perserverance.
5. Question: When did China first successfully land on Mars? (Bonus: how many nations had landed a mission to Mars before it?)
Answer: They landed on May 2021. Bonus: Two nations: the United States and the Soviet Union.
6. Question: Which two elements primarily make up Saturn and Jupiter?
Answer: Helium and hydrogen.
7. Question: From which direction does the Sun rise on Venus and why?
Answer: The sun rises from the west on Venus because it spins backwards on its axis.
8. Question: How many Earth years is a year on Pluto?
Answer: A year on Pluto is 248 Earth years.
9. Question: From 2004 to 2017, how many times did NASA’s Cassini orbit Saturn?
Answer: Cassini orbited Saturn 294 times.
10. Question: True or false: A day on Venus is longer than a year on Venus.
Answer: True! This is because Venus’s rotation on its axis is slower than the time it takes to orbit around the sun.
11. Question: What mineral causes Mars’s atmosphere and soil to appear red?
12. Question: When was Pluto first classified as a dwarf planet by the International Astronomic Union?
Answer: It was first classified as a dwarf planet in 2006.
13. Question: How many of Jupiter’s 80 moons have yet to be given official names by the International Astronomical Union?
Answer: 23 (as of January 2023).
14. Question: In days on Earth, how long is a year on Venus?
Answer: 225 Earth days.
15. Question: The names of many planets were used to form the names of the days of the week we use today. Which day did Saturn inspire?
16. Question: How many moons does Pluto have?
Answer: Pluto has five moons.
17. Question: Who was the first person to view Venus through a telescope? (Bonus: when did they view the planet?)
Answer: Galileo Galilei. Bonus: He viewed it in 1610.
18. Question: True or false: Mars has an especially thick atmosphere.
Answer: False! Mars’s atmosphere is unusually thin.
19. Question: What’s the name of Jupiter’s visible enormous storm that was first seen in the 1600s?
Answer: The Great Red Spot.
20. Question: What is the temperature of the Sun’s visible surface? (Bonus: what is the temperature of this surface?)
Answer: The Sun’s visible surface is called the photosphere. (Bonus: It is 10,000 degrees Fahrenheit).
21. Question: Is the first quarter or the last quarter of Earth’s moon’s phases brighter?
Answer: The first quarter.
22. Question: Which planet is home to the largest volcano ever discovered in our solar system? (Bonus: what’s the name of the volcano?)
Answer: Mars housed the largest volcano ever found in our solar system. Bonus: It was named Olympus Mons.
23. Question: What is the only planet in our solar system not named after a god or goddess?
24. Question: How many moons does Mars have and what are their names?
Answer: Mars has two moons named Phobos and Deimos.
25. Question: True or False: The Great Red Spot has been growing in recent years.
Answer: False. The Great Red Spot has been shrinking.
26. Question: Which of the following is not the name of a crater on Mercury: Caravaggio, Copernicus, Moody, Shevchenko? (Bonus: which planet does the outlier reside on?)
Answer: Copernicus. Bonus: It is a crater on Mars.
27. Question: Does Mercury experience weather changes?
Answer: No, only changes in temperature.
28. Question: Jupiter, Saturn, Uranus, and Neptune are often affectionately referred to as the “gas giants”. What is another word used to classify these planets?
Answer: They are Jovian planets.
29. Question: True or False: Mercury is hotter than Venus because it is closer to the Sun.
Answer: False. Venus is hotter than Mercury because of its thick carbon dioxide atmosphere.
30. Question: Do asteroids qualify as planets?
Answer: Kind of: they are also known as minor planets or planetoids.
31. Question: How many rings does Uranus have?
Answer: Uranus has 13 rings.
32. Question: Approximately how far away from the sun is Neptune, in miles?
Answer: Neptune is about 2.8 billion miles away from the Sun.
33. Question: How long is a year on Jupiter?
Answer: A year on Jupiter is 4,333 Earth days, or about 12 Earth years.
34. Question: How long is a day on Jupiter?
Answer: A day on Jupiter is only 9 Earth hours and 55 Earth minutes long because it spins on its axis so quickly.
35. Question: What is the most distant planet that can be seen without a telescope?
36. Question: Which planet was the first to be discovered through a telescope?
37. Question: What is the name of the largest moon in our solar system? (Bonus: which planet does it orbit?)
Answer: Ganymede. Bonus: It is a moon of Jupiter.
38. Question: Where does Earth’s moon rank in terms of size compared to other moons in our solar system?
Answer: Earth’s moon is the fifth largest moon in our solar system.
39. Question: What is the name of the deepest crater on Mars?
Answer: The Hellas Planitia, or Hellas Basin.
40. Question: When referring to the planet Venus, we often use the word “Venusian.” However, using Latin etymology rules, what word should we say instead?
Answer: “Venerian” is the correct Latin word meaning “pertaining to Venus.”
41. Question: Which is the smallest of the Jovian planets?
42. Question: Which is the densest Jovian planet?
43. Question: What is the technical term for the dusty, loose rock that sits on Mars’s surface? (Bonus: where else can this be found in the solar system?)
Answer: Regolith. Bonus: It can also be found on Earth and Earth’s moon.
44. Question: True or false: all of the eight planets in our solar system travel in circular orbits around the sun.
Answer: False: all of them travel in elliptical orbits, though not every orbit is an identical ellipse.
45. Question: Which planet is the densest one in our solar system and why?
Answer: Earth is the densest planet in our solar system due to its solid core.
46. Question: What is a term used to describe planets located outside of our solar system?
47. Question: Uranus’s two largest moons are named for Shakespearean lovers. What are their names?
Answer: Oberon and Titania.
48. Question: True or false: Jupiter has more than three times the mass of all the other planets in our solar system combined.
Answer: False: Jupiter has more than two times the mass of the other planets.
49. Question: Which of the following isn’t a dwarf planet in our solar system: Pluto, Makemake, Ceres, or Miranda?
Answer: Miranda isn’t a dwarf planet; it’s one of Uranus’s major moons.
50. Question: What is the name of the belt in which Pluto is located?
Answer: The Kuiper Belt.
51. Question: True or false: Saturn’s rings are very thick.
Answer: False: Saturn’s rings are deceptively thin.
52. Question: What is the geometric shape of the asteroid belt?
Answer: It is a torus shape.
53. Question: Why is gravity weaker on the Moon than on Earth?
Answer: This is because the Moon has less mass than Earth.
54. Question: What is a Near Earth Object?
Answer: A Near Earth Object is a piece of as asteroid that has broken off and traveled close to Earth.
55. Question: What does one astronomical unit equal in kilometers? (Bonus: what significant distance does one astronomical unit represent?)
Answer: One astronomical unit equals 150 million kilometers. Bonus: one astronomical unit is the length from the Sun to Earth.
56. Question: True or false: to be classified as a planet, a mass must be spherical.
57. Question: List the planets in our solar system in order from smallest to largest radius.
Answer: Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, Jupiter.
58. Question: How many Earth days is one day on Mercury?
Answer: One day on Mercury is equal to 176 days on Earth.
59. Question: What chemical compound are the clouds made of on Venus?
Answer: Venus’s clouds are made of sulfuric acid.
60. Question: True or false: Jupiter is the only planet in our solar system with an average density lower than water.
Answer: False. Saturn is the only planet in our solar system that is less dense than water. This means it could hypothetically float on water!
61. Question: Mercury does not have enough gravity to create an atmosphere. What does it have instead?
Answer: Mercury has an exosphere.
62. Question: What three elements make up the majority of Mars’s atmosphere?
Answer: Mars’s atmosphere is made up of carbon dioxide, argon, and nitrogen.
63. Question: What was the first NASA probe to land on Venus? (Bonus: when did it land?)
Answer: Venera 7 was the first NASA probe to land on Venus. Bonus: it landed on Venus’s surface in 1970.
64. Question: How many Jupiters could fit inside the Sun?
Answer: 11,000 Jupiters could fit inside the Sun.
65. Question: What three chemical compounds make up the ice on Uranus?
Answer: The ice on Uranus is made up of water, methane, and ammonia.
66. Question: How long does a season last on Neptune in Earth years?
Answer: A single season on Neptune lasts over 40 Earth years.
67. Question: Name the layers of the Earth from innermost to outermost.
Answer: Inner core, outer core, mantle, crust.
68. Question: What is the only NASA mission to make it to Pluto? (Bonus: when did it pass Pluto?)
Answer: NASA’s New Horizons is the only mission to pass by Pluto. Bonus: it arrived in 2015.
69. Question: Which planet’s equator is tilted 90 degrees opposite its orbit?
Answer: Uranus’s axis is tilted 90 degrees compared to its orbit.
70. Question: When did the Galileo mission explore Jupiter?
Answer: Galileo explored Jupiter from 1995 to 2003.
71. Question: True or False: Scientists think that another planet may exist in our solar system beyond the Kuiper Belt.
Answer: True. This hypothetical planet, dubbed “Planet X”, might explain the existence of the Kuiper Belt.
72. Question: What is the coldest known object in our solar system?
Answer: Triton, one of Neptune’s moons, is colder than any other object in our solar system.
73. Question: Which planet has the most moons? (Bonus: how many moons does it have?)
Answer: Saturn has the most moons. Bonus: it has 124 moons.
74. Question: How many degrees is Earth tilted on its axis?
Answer: Earth’s axis is tilted 23 degrees.
75. Question: How many Earth years does it take dwarf planet Makemake to orbit around the Sun?
Answer: It takes Makemake 310 Earth years to make its way around the Sun.
76. Question: Uranus is named after the Greek god of the sky, but what did astronomer William Herschel originally intend to name it and why?
Answer: Herschel wanted to name the planet “Georgium Sidus” in honor of King George III.
77. Question: Like Earth’s moon, Venus has phases. In Earth days, how long does it take Venus to complete its phase cycle?
Answer: It takes Venus 584 days to complete its phase cycle.
Alright, intergalactic friends! You’ve made it to the end of our 77 planetary trivia questions. We hope they’ve whetted your appetite for fun facts about our solar system. And if not, then we’ve got you covered: here are 111 MORE questions about our solar system!
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