What planet does Deimos orbit?

Deimos orbits Mars at an average distance of about 23,463 km, completing one lap every 1.3 days.

Deimos has a diameter of about 12 km and a mass of roughly 1.48 × 10¹⁵ kg.

Why is Deimos famous?

Deimos's claim to fame: the smaller and outer of Mars's two moons, a lumpy body only about 12 km across.

Deimos

Moon of Mars

Deimos facts

Orbits: Mars
Distance from Mars: 23,463 km (6.9 Mars-radii)
Orbital period: 1.3 days
Diameter: 12 km
Mass: 1.48 × 10¹⁵ kg
Orbital inclination: 1.79°
Tidally locked: Yes
Discovered: 1877, by Asaph Hall

Deimos orbits Mars

Watch Deimos (highlighted) circle Mars. Press play; the moons run at their real relative speeds.

SpeedRelative sizes and spacing are compressed; orbits shown coplanar. Click a moon for its page.

About Deimos

Deimos is the smaller, outer moon of Mars, a lumpy body just 12 km across. Like Phobos it is thought to be a captured asteroid or a leftover from an impact. It is so small that from the Martian surface it would look like a bright star that takes days to cross the sky.

Named after the Greek personification of dread, a son of Ares
Discovered: 1877, by Asaph Hall

Deimos: frequently asked questions

What is Deimos?: Deimos is the smaller, outer moon of Mars, a lumpy body just 12 km across.
What planet does Deimos orbit?: Deimos orbits Mars at an average distance of about 23,463 km, completing one lap every 1.3 days.
How big is Deimos?: Deimos has a diameter of about 12 km and a mass of roughly 1.48 × 10¹⁵ kg.
Why is Deimos famous?: Deimos's claim to fame: the smaller and outer of Mars's two moons, a lumpy body only about 12 km across.

See Deimos in motion

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Data from NASA/JPL and NSSDCA. Source.