MOON FACTS
The home of interesting Moon facts for kids and adults.
Interesting facts about Moons
You probably know a little about our moon, we can see it almost whenever we want, but what about the other moons of the solar system? There are quite a few of them and you may not know the names of some, but that's OK – that's why we are here.
According to NASA, there are 214 moons (158 confirmed, and 56 that scientists are fairly sure are there) in our solar system, too many to list on this page, and you’d think that with so many of them there must be some pretty interesting facts about them… There are, and here are our top 10.
1. Saturn has the most moons
The total number of moons orbiting Saturn is a whopping 82. It was thought that Jupiter had the most, with 79, but a team of researchers recently discovered a further 20. Each of the newly discovered moons measures around 3 miles in diameter.
Did you know?
17 of the newly observed moons orbit Saturn ‘backwards’ – this is called a retrograde orbit.
2. The largest moon in our system is Ganymede
Ganymede, a satellite of Jupiter’s, is easily the largest moon in our solar system. As well as being the largest moon, Ganymede is also the 9th largest object in the solar system, and that includes the Sun.
Did you know?
Ganymede is also larger than Pluto and Mercury.
3. Io is the most ‘active’ object in the Solar system
Io is a moon of Jupiter and is home to over 400 active volcanos. This makes it the most geologically active object in the solar system. All of this activity is due to tidal heating.
Did you know?
The interior of Io is perpetually pulled between Jupiter and two other moons – Ganymede and Europa. It is this pulling that causes tidal heating.
4. You could flap your arms to fly around Titan (maybe)
Titan is a moon of Saturn, and it is unique in its own right. Its atmosphere is around 372 miles thick and there is very low gravity. In theory, this combination would allow humans to fly around the planet like birds.
Did you know?
Titan is nearly Earth-like in terms of weather and terrain. It has lakes, rivers and seas (albeit of liquid methane) and it also has a methane-based (as opposed to water) weather system.
5. Triton is home to cryovolcanoes
Triton, a moon of Neptune, behaves quite strangely. Cryovolcanoes (these spew water and ammonia instead of lava) aside, the moon also has geysers. These can 'shoot' sublimated (a transition from solid to gas, without becoming liquid) several miles above the surface.
Did you know?
In around 3.6 billion years Triton will move to within Neptune's Roche limit (a gravitational distance that potentially tears two celestial bodies apart). When it does it will either collide with the planet or break up creating a new ring system.
6. Europa is a candidate for life
It is thought the outer crust, which is solid ice, is anywhere between 6 and 19 miles thick. Geologists estimate that the ocean that lies three ‘layers’ down could be 60 miles deep. This would mean the total volume of water on Europa could be 2 or 3 times the total volume of oceans here on Earth.
Did you know?
With the level of technology as it is right now, it would be almost impossible to drill down and sample Europa’s oceans.
7. Mimas looks like a Star Wars Death Star
There is a moon of Saturn that has a huge crater, making it look uncannily like the famous Death Star. The impact crater of Mimas very nearly shattered the moon, so it's lucky to still be around. The moon is fractured on the other side because of the impact crater.
Did you know?
The crater is almost one-third of the moon's total diameter. If Earth had a similar crater, one-third of its diameter, it would be wider than Australia.
8. Charon is the largest moon relative to the object it orbits
Pluto is a dwarf planet, and as if to prove it Charon is half its diameter. Charon is so big next to Pluto that it is sometimes called a double planet system..
Did you know?
It is thought that Charon, like Triton, also has active cryovolcanoes and cryogeysers.
9. Phobos orbits faster than Mars rotates
Phobos, a moon of Mars, appears to rise and set twice each Martian day. This is because the moon orbits the planet faster than the planet rotates on its axis.
Did you know?
One day Mars will enter Mars' Roche limit. This means it will either collide with the planet or form a ring(s) around the planet after breaking up.
10. NASA once protected Europa, in case it has life.
NASA had a perfectly functional spacecraft called Galileo and sent it crashing into Jupiter. The agency said it did this so it didn't hit Europa because it is thought the moon may contain life.
Did you know?
NASA didn’t want to potentially hurt any life that may live on the moon, so before the spacecraft ran out of fuel it was diverted to crash into the planet instead.