Is the Earth the Only Planet with a Moon?

We call our moon “the moon” because it’s the only moon that earth has. But some of the other planets have moons too. And all of the planets that do have moons have more than one!

Mars and Neptune each have two moons, Uranus has five moons, and Saturn has ten. Jupiter, the largest planet, has 14 moons, the last one was discovered as recently as 1975.

Mercury and Venus have no moons. But astronomers think that Pluto, the farthest planet from the sun, might have a single moon. So far, the earth is the only planet known to have just one moon.

One of Jupiter’s moons, called Ganymede, is the largest moon in the solar system. It’s about 3,275 miles across, which makes this moon bigger than Mercury, a planet!

The smallest moon in the solar system, Mars’s Deimos, is only about eight miles across, a distance you could walk in half a day!