Martian Moons

Phobos and Deimos

(moons of Mars)

Mars has two small moons: Phobos and Deimos. Phobos (fear) and Deimos (panic) were named after the horses that pulled the chariot of the Greek war god Ares, the counterpart to the Roman war god Mars. Both Phobos and Deimos were discovered in 1877 by American astronomer Asaph Hall. The moons appear to have surface materials similar to many asteroids in the outer asteroid belt, which leads most scientists to believe that Phobos and Deimos are captured asteroids

Two Moons Passing in the Night

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  This animation shows Phobos as a large white dot against a black background, representing Phobos, moving from the lower center toward the upward right corner. Above and to the left of it is Deimos, a smaller white dot, that also moves upward and to the right but at a much slower pace. In fact, Phobos starts out below Deimos, the smaller dot, and quickly moves past it in the sequence.
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  This animation shows a large white dot against a black background, representing Phobos, moving from the lower center toward the upward right corner. Above and to the left of it is a smaller white dot, representing Deimos, that also moves upward and to the right but at a much slower pace.

Two Moons and the Pleiades from Mars

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  This image shows on the upper right side, is a small white circle against a black background representing Phobos, with a smaller black circle representing Deimos a little above and to the right of it.
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  This image shows a large white circle representing an enhanced image of the light from Phobos with an oblong rock-like object representing Phobos itself inserted in the middle. A little above and to the right of that is a smaller white circle representing Deimos. In the lower left corner are several white pinpoints labeled 'The Pleiades.'

Phobos Viewed from Mars

See the Spirit Press Release for additional information.