Space potato 🥔 Phobos is the larger of Mars' two moons—but it's still only about 17 x 14 x 11 miles (27 by 22 by 18 kilometers) in diameter. Because Phobos is so small, its gravity isn't strong enough to pull it into a sphere (like Earth's Moon), giving it its lumpy shape. Phobos is also on a collision course with Mars—though it'll take a while to get there. It's nearing the Red Planet at a rate of six feet (1.8 meters) every hundred years. At that rate, the moon will either crash into Mars in 50 million years or break up into a ring. This image was taken by the High Resolution Imaging Science Experiment (HiRISE) camera on our Mars Reconnaissance Orbiter, which has been studying Mars since 2006. Image description: The Martian moon Phobos stands against the darkness of space. The moon is brownish-red and lumpy, pocketed with a number of craters of all sizes. A white patch is visible next to Stickney crater, a particularly large crater on its right side. Credit: NASA/JPL-Caltech/...