Moons of Mars other small moons that suffered the fate expected of Phobos, and that the Martian crust as a whole shifted between these events. Deimos, on the other hand, is far enough away that its orbit is being slowly boosted instead, as in the case of our own Moon. The origin of the Martian moons is still controversial. Phobos and Deimos both have much in common with carbonaceous C-type asteroids, with spectra, albedo, and density very similar to those of C- or D-type asteroids. Based on their similarity, one hypothesis is that both moons may be captured main-belt asteroids. Both moons have
Phobos 2 to approach within of Phobos' surface and release two landers, one a mobile , the other a stationary platform, contact with "Phobos 2" was lost. The mission ended when the spacecraft signal failed to be successfully reacquired on 27 March 1989. The cause of the failure was determined to be a malfunction of the on-board computer. The "Phobos 2" infrared spectrometer (ISM) obtained 45000 spectra in the near infrared (from ) in the equatorial areas of Mars, with a spatial resolution ranging from , and 400 spectra of Phobos at 700 m resolution. These observations made it possible to retrieve