Released today, this photo from the HiRISE camera aboard the MRO shows the smooth face of Deimos, Mars’ smaller moon. (Its larger brother is Phobos, also photographed by the HiRISE in 2008.) Its surface is covered by a fine layer of rocky soil, called regolith, which gives it its smooth texture.
Deimos is only about 6-7 miles wide. Both it and Phobos are thought to have once been asteroids captured by Mars, perhaps after first being knocked from their own orbits by the massive gravity of Jupiter.
Deimos and Phobos are named after the Greek gods of panic and fear, respectively. Fitting for moons of Mars, whose Roman namesake is the bringer of war.
Image credit: NASA/JPL/University of Arizona