12 space questions with answers
Someone at the table is sure Pluto is still a planet. Someone else thinks the far side of the Moon is always dark. October is a good month to settle it: Saturn has just been at its brightest, and the Orionid meteors are due later this month.
Here are twelve space questions, each with four options, a short answer, and a source. They suit a rooftop, a late train, or a group chat that has gone quiet.
How to run it
Read the question and all four options before anyone answers. Let everyone lock in a guess, then read the answer and the one-line reason. Nobody needs to keep score. The fun is in who was confidently wrong.
The questions
1. How many planets are there in our solar system?
- A) 7
- B) 8
- C) 9
- D) 12
Answer: B. Eight: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto was reclassified as a dwarf planet in 2006. (NASA Science, accessed October 2026.)
2. Which planet is nearest the Sun?
- A) Venus
- B) Earth
- C) Mercury
- D) Mars
Answer: C. Mercury is the innermost and smallest planet. Venus is next, then Earth, then Mars.
3. Which planet is the hottest?
- A) Mercury
- B) Venus
- C) Mars
- D) Jupiter
Answer: B. Venus, even though Mercury is closer to the Sun. A thick carbon-dioxide atmosphere traps heat, so the surface is hot enough to melt lead. (NASA Science, accessed October 2026.)
4. Why do we only ever see one face of the Moon from Earth?
- A) The far side is always dark
- B) The Moon does not rotate
- C) The Moon rotates in the same time it takes to go around Earth
- D) Earth blocks the other side
Answer: C. The Moon is tidally locked: it turns once per orbit, so the same hemisphere faces us. The far side gets just as much sunlight; we simply never see it from the ground. (NASA Science, accessed October 2026.)
5. In which year did astronomers reclassify Pluto as a dwarf planet?
- A) 1996
- B) 2001
- C) 2006
- D) 2015
Answer: C. 2006, by the International Astronomical Union. A spacecraft still flew past Pluto in 2015; the visit did not put it back on the planet list. (NASA Science, accessed October 2026.)
6. Why does Mars look red?
- A) It is on fire
- B) Iron in the dust and rock has rusted
- C) Its atmosphere is made of blood-red gas
- D) It reflects a red star
Answer: B. Iron minerals oxidise, and the rust-coloured dust gets kicked into the air, so the planet looks red from a distance. (NASA Science, accessed October 2026.)
7. How many moons does Mars have?
- A) None
- B) One
- C) Two
- D) Four
Answer: C. Two small, potato-shaped moons, Phobos and Deimos. They may be captured asteroids. (NASA Science, accessed October 2026.)
8. The dark patches on the Moon are called maria. What does that Latin word mean?
- A) Mountains
- B) Seas
- C) Shadows
- D) Cities
Answer: B. Seas. They are not water. They are old impact basins that filled with lava billions of years ago. (NASA Science, accessed October 2026.)
9. Which Indian spacecraft first found clear signs of water on the Moon?
- A) Mangalyaan
- B) Chandrayaan-1
- C) Aryabhata
- D) Vikram
Answer: B. Chandrayaan-1, in 2008, detected hydroxyl molecules across the lunar surface, concentrated at the poles. Later missions confirmed ice in the permanently shadowed craters. (NASA Science, accessed October 2026.)
10. The Orionid meteor shower is made of debris from which comet?
- A) Hale-Bopp
- B) Encke
- C) Halley
- D) Shoemaker-Levy
Answer: C. Halley's Comet. The shower peaks around 21 to 22 October. The meteors can streak anywhere in the sky; they only appear to come from Orion. (NASA Science, October 2026 skywatching notes.)
11. When Saturn is "at opposition", what is happening?
- A) Saturn is behind the Sun
- B) Earth is between the Sun and Saturn
- C) Saturn has no rings that night
- D) Saturn is closer than the Moon
Answer: B. Saturn sits opposite the Sun in our sky, so it rises around sunset and stays up most of the night. That happened on 4 October 2026. (NASA Science, October 2026 skywatching notes.)
12. Where is Ceres?
- A) Between Mars and Jupiter
- B) Beyond Neptune
- C) Orbiting the Moon
- D) Inside the Sun
Answer: A. Ceres is a dwarf planet in the main asteroid belt, the only dwarf planet in the inner solar system, and the first one a spacecraft visited. (NASA Science, accessed October 2026.)
Where this does not work
This is a casual round, not a skywatching briefing or a safety guide. Peak dates for showers shift a little each year, and city lights will hide most meteors anyway. Skip anything medical, skip "is there life on Venus", and if a question turns into a real argument, look it up together. Definitions change too, which is why Pluto carries a year.
Use it in QuesMo
Each of these works as a four-option question in QuesMo, where a friend picks an answer and sees whether they got it. To write your own, see make one good four-option question. Want another round? Try the everyday science questions or the food and drink questions.