Phobos program Phobos program The Phobos (, ) program was an unmanned space mission consisting of two probes launched by the Soviet Union to study Mars and its moons Phobos and Deimos. "Phobos 1" was launched on 7 July 1988, and "Phobos 2" on 12 July 1988, each aboard a Proton-K rocket. "Phobos 1" suffered a terminal failure en route to Mars. "Phobos 2" attained Mars orbit, but contact was lost before the final phase, prior to deployment of a planned Phobos lander. "Phobos 1" and "2" were of a new spacecraft design, succeeding the type used in the "Venera" planetary missions
Transit of Phobos from Mars transit of Phobos from Mars usually lasts only thirty seconds or so, due to the moon's very rapid orbital period of about 7.6 hours. Because Phobos orbits close to Mars and in line with its equator, transits of Phobos occur somewhere on Mars on most days of the Martian year. Its orbital inclination is 1.08°, so the latitude of its shadow projected onto the Martian surface shows a seasonal variation, moving from 70.4°S to 70.4°N and back again over the course of a Martian year. Phobos is so close to Mars that it is not visible south of 70.4°S or