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
Mars Exploration Program used toward a mission that is part of the Mars Sample Return program. As a result of the smaller budget for the MEP, NASA was forced to cancel the Mars Science Orbiter planned for 2016 that would have studied the climate of the planet. NASA does not have any missions for the future of the MEP, as a plan is still being developed that will encompass the next few decades. Mars Exploration Program The Mars Exploration Program (MEP) is a long-term effort to explore the planet Mars, funded and led by NASA. Formed in 1993, MEP has made use of