13 Deimos Moon Facts | Awesome Facts about Deimos

Deimos is one of the smallest moons in our solar system, and one of the two moons that orbit around the Mars, the planet. It takes its name from the Greek son of Ares, which when translated into English, literally means “dread”, or “terror”. But does this small moon really deserve such a vicious name? Well, lets look at some of the facts about the moon Deimos to find out.


Deimos Moon Facts

  1. Deimos is very small for a moon, as it has a radius of only 6.2km.
  2. It is the smaller of the two moons that orbit Mars. The other moon, Phobos, is almost twice the size of Deimos.
  3. Deimos has a distance of 14,580 miles (23,460 km) away from Mars.
  4. Whilst its twin moon is closer to Mars and can orbit it relatively quickly, it takes more than 30 hours for Deimos to orbit Mars.
  5. Both moons take their name from the God Ares, who is the Greek equivalent of Mars. Their names literally mean fear (Phobos) and Terror (Deimos).
  6. Deimos is considered by many astronomers to be an asteroid, that has been “captured” in the gravity of Mars.
  7. Whilst both Mars moons were discovered within a week of each other, Deimos was discovered first out of the two.
  8. It can be difficult to spot this moon, as the surface of Deimos is very dark with less than 7% reflectiveness. Both moons have a lot of craters, but Deimos is the smoother of the two. It only has 2 officially named craters.
  9. The largest crater on Deimos, Voltaire, is has a 1.9 mile (3km) diameter. It takes its name from the French writer who predicted that Mars had two moons in the 18th Century.
  10. The Earth is more than 1000x the size of Deimos.
  11. Deimos has a weird shape, kind of like a potato. This is why some astronomers think that it’s an asteroid that’s been captured by the gravity of Mars. This is pretty likely, as the asteroid belt runs between Mars and Jupiter.
  12. Deimos isn’t large enough to have any atmosphere, and it has very low surface gravity, which is why is isn’t circular or oval shaped.
  13. Although there is a mission planned to go to Phobos, there is no mission to Deimos as of yet. This moon still hasn’t been visited.

Common Questions about Deimos

Does Deimos have an atmosphere?

Both Deimos and its twin brother Phobos are very small moons. Because they are too small, they don’t have an atmosphere like the planets do – their gravity isn’t strong enough to maintain at atmosphere because of their low mass. So no, Deimos doesn’t have an atmosphere like Earth.

Why isn’t Deimos spherical?

The same reason that Deimos doesn’t have an atmosphere is the same reason why it isn’t spherical or shaped like an ellipse. The reason why objects like planets become spherical is because of their gravity, which pulls the planet out in each directly equally (or fairly equally). The gravity on Deimos is so low that it does not pull the object out, so it stays in it’s strange potato-like shape.

How many craters does Deimos have?

We know that both Phobos and Deimos have a lot of craters on them, though Phobos has more out of the two moons. Although, we don’t know just how many craters that Deimos has on its surface. Only two of these craters have been named and identified, Voltaire and Swift. It’s difficult to make out the surface and craters on Deimos clearly due to its small size and gray color.

Where does Deimos take it’s name from?

Deimos takes its name directly from the Greek deity, which when translated into English means “dread”. He is the son of Ares and Aphrodite, and appears in many mythological books like The Iliad.

What is Deimos made of?

Deimos is made from the same materials as asteroids, which leads astronomers to believe that it might actually be an asteroid in Mars’ orbit. It is made up primarily of carbon-rich rock.


So, we know that Deimos is the smaller of the two moons that orbit Mars, and it’s much further out too. How it came to be is still deliberated by astronomers, with some thinking it’s an asteroid, whilst others believe it formed more recently from a collision.