Phobos 360

The innermost moon of Mars, Phobos, is seen here in full 360 degree glory. The images were taken by the High Resolution Stereo Camera (HRSC) on ESA’s Mars Express at various times throughout the mission’s 10 years. The moon’s parallel sets of grooves are perhaps the most striking feature, along with the giant 9 km-wide Stickney impact crater that dominates one face of the 27 x 22 x 18 km moon. The origin of the moon’s grooves is a subject of much debate. One idea assumes that the crater chains