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Who discovered Phobos and Deimos?
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Mars
An especially serene view of Mars (Tharsis side), a composite of images taken by the Mars Global Surveyor spacecraft in April 1999. The northern polar cap and encircling dark dune field of Vastitas Borealis are visible at the top of the globe. White water-ice clouds surround the most prominent volcanic peaks, including Olympus Mons near the western limb, Alba Patera to its northeast, and the line of Tharsis volcanoes to the southeast. East of the Tharsis rise can be seen the enormous near-equatorial gash that marks the canyon system Valles Marineris.
The two moons of Mars, Phobos and Deimos, were discovered in 1877 by the American astronomer Asaph Hall.123
Hall, who served as a professor of mathematics at the U.S. Naval Observatory, identified both satellites telescopically that year and subsequently calculated their orbits. He named the moons after the personifications of panic and dread from Greek mythology, who were the sons of Ares—the Greek counterpart to the Roman god Mars.123