Deimos, the smaller of Mars’s two moons, is a tiny speck of a thing, with a mean radius of only 6.2 km. (Small for a moon.) But the HiRISE camera aboard the Mars Reconnaissance Orbiter took two pictures of Deimos, 5½ hours apart, last month.

(The same camera nabbed Phobos, the larger moon, in March 2008, and also caught an avalanche in progress on the Martian surface, to say nothing of the Phoenix lander’s arrival. HiRISE is made of awesome.)

Via Bad Astronomy.

(Image credit: NASA/JPL/University of Arizona.)