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Phobos

[Image of Phobos]

Mean Radius:
9.2 x 13.4 km

Mass:
1.08x1016 kg

Orbital Period:
0.319 Earth days

Rotation Period:
0.319 Earth days

Orbit:
9,378 km from Mars

Phobos is the larger, innermost of Mars' two moons. Deimos is the other moon.

Web Pages with Information about Phobos

Astrogeology Research Program

Browse the Solar System: Interactive version of our popular poster Mapping the Solar System
Browse the Geologic Solar System: Interactive version of our popular poster Geology of the Solar System
Gazetteer of Planetary Nomenclature: Information about and access to the official International Astromical Union approved names for planetary features
Cartographic Coordinates and Rotational Elements of the Planets and Satellites - IAU Working Group: IAU CCRE Working Group, information, publications, and references, including tables of the accepted values for the size, shape, and rotations of the planets and satellites
NASA Planetary Photojournal: Images from various Solar System exploration programs

Other Web Sites