Meet Phobos, one of two tiny moons in orbit around Mars. Phobos is Greek for fear, an appropriate name we think for a moon that orbits a planet named for a god of war. We fear that time for Phobos might be short. The moon is so close to Mars (about 5,800 kilometers above the surface compared to 400,000 kilometers for our own moon) that gravitational forces are pulling it down, leading to an inevitable crash with the planet.
However, don't be too sad for Phobos -- it isn't going anywhere anytime soon. It's got another 100 million years or so before it meets its shattering demise. In the meantime, we can ooh and ahh over Stickney Crater, seen here. At over 9 kilometers across, Stickney is nearly half the diameter of Phobos itself. It's so large, NASA thinks the impact that blasted out the crater likely came close to shattering the tiny moon.
Image Courtesy NASA
