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Phobos orbits Mars at a distance closer than the distance of a synchronous orbit. For that reason, Phobos actually rises in the ''west'' and sets in the ''east'' of the Martian sky.<ref name=planetsoc>"[http://www.planetary.org/explore/topics/our_solar_system/mars/phobos.html Entry for Phobos]." The Planetary Society. Accessed February 11, 2008.</ref> Yet because Phobos orbits Mars so closely, it is not visible above the horizon at latitudes higher than 70° north or south.

Phobos orbits Mars at a distance closer than the distance of a synchronous orbit. For that reason, Phobos actually rises in the ''west'' and sets in the ''east'' of the Martian sky.<ref name=planetsoc>"[http://www.planetary.org/explore/topics/our_solar_system/mars/phobos.html Entry for Phobos]." The Planetary Society. Accessed February 11, 2008.</ref> Yet because Phobos orbits Mars so closely, it is not visible above the horizon at latitudes higher than 70° north or south.

Phobos is not round, but is shaped like a [[potato]], with dimensions 27 x 21.6 x 18.8 km. Its most remarkable surface feature is Creater Stickney, named for the family of Mrs. Asaph Hall. Stickney has a diameter of 10 km, and its outer rim has pronounced surface striations suggesting a tremendous impact.<ref name=nasa2>"[http://marsprogram.jpl.nasa.gov/facts/phobos.html Entry for Phobos]." Mars Exploration Program, [[NASA]]. Accessed February 11, 2008.</ref><ref name=planetsoc/>

Phobos is not round, but is shaped like a [[potato]], with dimensions 27 x 21.6 x 18.8 km. Its most remarkable surface feature is Crater Stickney, named for the family of Mrs. Asaph Hall. Stickney has a diameter of 10 km, and its outer rim has pronounced surface striations suggesting a tremendous impact.<ref name=nasa2>"[http://marsprogram.jpl.nasa.gov/facts/phobos.html Entry for Phobos]." Mars Exploration Program, [[NASA]]. Accessed February 11, 2008.</ref><ref name=planetsoc/>

Phobos is spiraling in toward Mars at a rate of 18 mm per year. At that rate, if it had 50 million years to wait, it would enter the Martian atmosphere and drop to the surface in a cataclysmic crash, or else disintegrate into a ring.<ref name=nasa1/>

Phobos is spiraling in toward Mars at a rate of 18 mm per year. At that rate, if it had 50 million years to wait, it would enter the Martian atmosphere and drop to the surface in a cataclysmic crash, or else disintegrate into a ring.<ref name=nasa1/>