Phobos (moon)
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Phobos is the innermost and larger of the two natural satellites of Mars, the other being Deimos. The two moons were discovered in 1877 by American astronomer Asaph Hall. It is named after Phobos, the Greek god of fear and panic, who is the son of Ares (Mars) and twin brother of Deimos.
Enhanced color image of Phobos, as captured by the Mars Reconnaissance Orbiter. Stickney, the largest crater on Phobos, is on the right.
Asaph Hall III, discoverer of Phobos
The Phobos monolith (right of center) as taken by the Mars Global Surveyor (MOC Image 55103, 1998).
Image: Stickney mro
Asaph Hall
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Asaph Hall III was an American astronomer who is best known for having discovered the two moons of Mars, Deimos and Phobos, in 1877. He determined the orbits of satellites of other planets and of double stars, the rotation of Saturn, and the mass of Mars.
Hall's former home in the Georgetown neighborhood of Washington, D.C., after enlargement. Note Angeline on front steps and two workers.
Hall's Gold Medal of the Royal Astronomical Society