Moons of Mars

natural satellites orbiting Mars

Mars has two little moons, Phobos and Deimos, which are thought to be captured asteroids.[1] They were found by Asaph Hall in 1877.[2]

Phobos (top) and Deimos (bottom).


Name and how to say
its name
Image diameter (km) Mass (kg)
Mars I Phobos /ˈfoʊbəs/
22.2 km (27×21.6×18.8) 1.08×1016
Mars II Deimos /ˈdaɪməs/
12.6 km (10×12×16) 2×1015


  1. John P. Millis. "Mars Moon Mystery".
  2. "The Planet Mars: A History of Observation and Discovery. Chapter 5: 1877. University of Arizona Press". Retrieved 2013-02-28.