The Solar SystemMoons |
How many moons does Mars have? |
Mars has two moons, Phobos and Deimos. They were discovered in 1877 by the American astronomer Asaph Hall (1829–1907).
Mars’ two moons are Phobos (top), which has a radius of about 6.9 miles (11.1 kilometers); and Deimos, below, has an even smaller radius of 3.9 miles (6.2 kilometers). (Jet Propulsion Lab/California Institute of Technology—taken by Mars Reconnaissance Orbiter)