Mariner 9 was the first spacecraft to image Mars' moons. It revealed Phobos to be a heavily cratered world, with one enormous crater, named Stickney, taking a large bite off of one end. But the largest crater visible in many of these photos is Hall, which overlaps Phobos' south pole. These images were taken between December 1, 1971 and February 2, 1972.
Images have had salt-and-pepper noise removed. All have been brightened. A few data dropouts appear as black stripes across some images. Images are at their original resolution.