Mars and Deimos - Illustration - Mars and Deimos - Illustration - Artist's view of...

Mars and Deimos - Illustration - Mars and Deimos - Illustration - Artist's view of Deimos, the smallest of Mars's two satellites. This is how Mars and its even smaller satellite Deimos might appear from a distance of about 100 miles from the surface of Deimos. Deimos is over Acidalia Planitia, an albedo feature that has been observed by Earth - bound astronomers since the 19th century. To the southwest are the fog - filled canyons of Valles Marineris, the westernmost of which are still in darkness. Beyond Mars, immediately to the left of its night side, is Phobos at a distance of 20,000 miles. The two bright objects in the lower left are the stars Beta Gruis and Al Nair in the southern constellation Grus. Like it's larger companion Phobos, Deimos does not possess enough mass to pull itself into a sphere; its shape instead is oblong with a length of about 10 miles and only 6 miles wide at its smallest dimension. Like Phobos, Deimos may be an asteroid long ago captured by Mars' gravity. Orbiting 14,600 miles above Mars' surface, Deimos completes one revolution every 30 hours