A complete view of Phobos
This animation of Phobos, the larger of the two Martian satellites, was created using a combination of images from the High Resolution Stereo Camera (HRSC) on board the Mars Express orbiter along with some images taken in 1977 during an intensive scientific investigation of Phobos by the Viking Orbiter-1.
Mars Express is currently the only spacecraft orbiting the Red Planet that is able to view Phobos close up. The nature of Mars Express' highly elliptical, polar orbit brings it close to Phobos every six months. The suite of seven instruments onboard Mars Express, primarily used to study the atmosphere and surface of the Red Planet, can also be successfully used to examine Phobos.