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
Phobos monolith astronaut Buzz Aldrin has spoken about the Phobos monolith and his support for a mission to Phobos. The object appears in Mars Global Surveyor images SPS252603 and SPS255103, dated 1998. The object is unrelated to another monolith located on the surface of Mars, which NASA noted as an example of a common surface feature in that region. Phobos monolith The Phobos monolith is a large rock on the surface of Mars's moon Phobos. It is a boulder about across and tall. A monolith is a geological feature consisting of a single massive piece of rock. Monoliths also occur naturally on