Stereo views of Phobos

Caption NASA originale:"The upper pair shows the side facing away from Mars at a range of 500 Km from the Viking 1 Orbiter. The large craters near the limb are about 4 Km across and a few hundred meters deep. The lower pair shows the side facing Mars at a range of 300 Km.
The grooves are radiating from Stickney and are tens of kilometers long, hundreds of meters wide and can be tens of meters deep".