Book 8, Question 67
Why Do Some Planets Have Dozens of Moons?
Some planets have dozens of moons because strong gravity can capture passing objects, and it can also keep leftover pieces from the planet's formation circling nearby. Giant planets are heavy, so they have lots of pull, and lots of room around them. They won the moon jackpot!
More fun facts
- Hundreds of moons orbit planets, dwarf planets, asteroids and icy objects beyond Neptune.
- More than 470 confirmed moons circle dwarf planets, asteroids and other small worlds.
- Most planet moons probably formed from discs of gas and dust that swirled around the young planets.
- Moons come in many shapes, sizes and types.
- In 2009, the Hubble Space Telescope photographed four of Saturn's moons passing in front of the planet at once.
Sources: NASA Science, NASA Science
Questions kids ask
Do asteroids have moons?
Yes. Moons also orbit some asteroids and dwarf planets.