Moons of Mars Proposed NASA's PADME mission proposes to launch in 2020 and reach Mars orbit in 2021 to conduct multiple flybys of the Martian moons. Also, NASA is assessing the OSIRIS-REx II, concept mission for a sample return from Phobos. Another sample return mission from Deimos, called Gulliver. has been conceptualized. Russia plans to repeat Fobos-Grunt mission around 2024. Moons of Mars The two moons of Mars are Phobos and Deimos. Both were discovered by Asaph Hall in August 1877 and are named after the Greek mythological twin characters Phobos (panic/fear) and Deimos (terror/dread) who accompanied their father Ares, god of war,
Transit of Phobos from Mars the autumnal equinox and the vernal equinox, while farther from the equator they happen closer to the winter solstice. Observers at high latitudes (but less than 70.4°) will see a noticeably smaller angular diameter for Phobos because they are considerably farther away from it than observers at Mars's equator. As a result, transits of Phobos for such observers will cover less of the Sun's disk. Because it orbits so close to Mars, Phobos cannot be seen north of 70.4°N or south of 70.4°S; observers at such latitudes will obviously not see transits, either. Mars Rover "Opportunity" rover photographed transits of