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Mars' Moons

Mars has two small moons, Phobos and Deimos. Phobos is the larger of the two. It is shaped like a potato, about 15 miles long by 10 miles wide. One end is scarred by a giant crater. The impact that created it may have fractured the entire moon, leaving big cracks that travel from one end to the other. Phobos is in such a low orbit that it circles Mars about three times per day. It rises in the west, then sets in the east just a few hours later. As seen from the equator it looks less than half as big as our Moon looks from Earth. Deimos is both smaller and farther out. It takes almost three days to complete one orbit. From the Martian surface, it looks about like Venus looks from Earth.


Mars' Moons February 19, 2016


Mars February 10, 2016

Radio Programs

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Featured Images

artist's concept of mmx spacecraft with mars moons in background

Sampling a Martian Moon August 21, 2023

Emirates Mars Mission view of Deimos in front of Mars

Family Portrait April 28, 2023

Artist's concept of astronauts on Phobos, a moon of Mars

Charged Moon May 13, 2020

Deimos and Saturn from Mars Express

Two for One March 3, 2018