1 day / second
0.5 AU
Deimos
Moon of Mars
A tiny, irregularly shaped moon that orbits Mars every 30.3 hours at a distance of 23,460 km above the planet's surface.
Key Facts
learn more | Wikipedia |
mass | 1.4762e+15 kg |
radius | 6.2 km |
semi-major axis | 23,458 km |
eccentricity | 0 |
inclination | 26.12º |
longitude of the ascending node | 0º |
argument of periapsis | 0º |
orbital period | 1.262 days |
sidereal rotation period | 1.263 days |
axial tilt | 0º |
discovery date | August 12, 1877 |
discovered by | Asaph Hall |
name origins | Named after Deimos, one of the twin sons of Ares (Mars) in Greek mythology |
dimensions | 12.4 km diameter |
albedo | 0.068 |
density | 1.471 g/cm³ |
material composition | Likely composed of carbon-rich rock |
rotation | Tidally locked to Mars |
Gallery
Parent Planet
Mars
A cold, dusty red planet with massive extinct volcanoes, deep canyons, frozen polar caps, and evidence of ancient water flows, making it the most Earth-like planet in the Solar System.
Spacecraft Visits
Hera
Flyby
Launched in 2024, visited in 2025
Hera conducted a flyby of Deimos on October 7, 2025, capturing detailed images and measurements of the small Martian moon during its journey to study the binary asteroid system Didymos.
