Phobos was discovered by astronomer Asaph Hall on 18 August 1877 at the United States Naval Observatory in Washington, D.C., at about 09:14 Greenwich Mean Time. … See more

The orbital motion of Phobos has been intensively studied, making it "the best studied natural satellite in the Solar System" in terms of orbits completed. Its close orbit around … See more

Launched missions
Phobos has been photographed in close-up by several spacecraft whose primary mission has been to photograph Mars. The first was Mariner 7 in 1969, followed by Mariner 9 in 1971, Viking 1 in 1977, Phobos 2 See more

• Phobos Profile at NASA's Solar System Exploration site
• HiRISE Phobos
• USGS Phobos nomenclature
• Asaph Hall and the Moons of Mars See more

Phobos has dimensions of 26 km × 23 km × 18 km, and retains too little mass to be rounded under its own gravity. Phobos does not have an atmosphere due to its low mass and low … See more

The origin of the Martian moons has been disputed. Phobos and Deimos both have much in common with carbonaceous C-type asteroids, with spectra, albedo, and density very … See more

• List of natural satellites
• List of missions to the moons of Mars
• Phobos monolith See more