Planets quiz

More questions about Planets

These visible examples show the question style. LearnClash turns the full topic into ranked duels and spaced repetition.

1. 1 Easy

   Which two small moons orbit the red planet Mars?

   Answer: Phobos and Deimos

   Why: Their names translate to 'fear' and 'dread' in Greek mythology, appropriately flanking the Roman god of war.

2. 2 Medium

   What precious stone is thought to rain deep inside the planet Neptune?

   Answer: diamonds

   Why: A 2017 experiment squeezed plastic to 150 gigapascals and 5,000 degrees at a laser facility, and nanodiamonds formed just as the models predicted.

3. 3 Hard

   Which planet features a canyon system as long as the United States?

   Answer: Mars

   Why: It runs about four thousand kilometres, close to the widest span of the mainland United States, and in places it drops seven kilometres deep.

4. 4 Easy

   Which layer of Earth's atmosphere reaches the lowest temperatures?

   Answer: Mesosphere

   Why: Little ozone absorbs sunlight there, and carbon dioxide radiates heat to space, so the mesosphere sinks to about minus 90 degrees Celsius.

5. 5 Medium

   What term describes a planet spinning clockwise, opposite to most planets' rotation?

   Answer: Retrograde rotation

   Why: Venus and Uranus spin backward compared to the other planets, causing the Sun to rise in the west on Venus.

6. 6 Hard

   Approximately how many hours does it take Jupiter to rotate once?

   Answer: 10 hours

   Why: It is not a solid body, so there are three official rotation rates; the IAU uses the magnetic field's 9 hours 55 minutes and 30 seconds.