This is the Stickney Crater. It is found on the Martian moon Phobos, and it is certainly the tiny Moon’s largest crater. Named after the wife of the astronomer who discovered both of Mars’ moons, Asaph Hall, the crater itself spans about half of the diameter of Phobos. The impact was obviously a dramatic event and probably came close to obliterating the moon.
This image was taken in 2008 by the Mars Reconnaissance Orbiter’s HiRISE camera when it made a close pass (within 6,000 kilometers) of Mars’ tiny companion. The image is taken in enhanced-color and it reveals two interesting things about the crater. First, we see some streaks that look like material has slid down the crater walls – in spite of Phobos having about 1/1000th Earth’s gravity. Second, there are groove on the surface – these are thought to be related to the devastating impact that caused the crater to form in the first place.