Solar eclipses on Mars Solar eclipses on Mars The two moons of Mars, Phobos and Deimos, are much smaller than the Moon, greatly reducing the frequency of solar eclipses on that planet. Neither moon's apparent diameter is large enough to cover the disk of the sun, and therefore they are annular solar eclipses and can also be considered transits. Due to the small size of Phobos (about ) and its rapid orbital motion, an observer on the surface of Mars would never experience a solar eclipse for longer than about thirty seconds. Phobos also takes only 7 hours 39 minutes to orbit Mars, while
Martian Moons Exploration grams of soil into the sample container. The spacecraft will then take off from Phobos and make several flybys of the smaller moon Deimos before sending the Sample Return Capsule back to Earth, arriving in July 2029. Martian Moons Exploration The Martian Moons Exploration (MMX) is a robotic space probe set for launch in 2024 to bring back the first samples from Mars' largest moon Phobos. Developed by the Japanese Aerospace Exploration Agency (JAXA) and announced in 9 June 2015, MMX will land and collect samples from Phobos once or twice, along with conducting Deimos flyby observations and monitoring Mars'