The Moons of Other Planets The moons of other planets range in size from very small to as large as terrestrial planets. Venus and Mercury have no moons. All of the outer planets have multiple moons. Some moons orbit their planets backwards! Moons may be some of the most bizarre and interesting places in the solar system. Chapter 16-4 Part 2 Part 2

The Moons of Mars Phobos and Deimos are small, oddly shaped satellites. They look much like asteroids. One possibility is that these two moons are asteroids that were caught by Mars’s gravity.

The Moons of Jupiter Jupiter has more than 60 moons. The four largest were discovered by Galileo in 1610. Ganymede is the largest. It is larger than the planet Mercury. Io is the most volcanically active body in the solar system. Recent information suggests Europa may have liquid water beneath its icy surface. Callisto may also have water beneath its surface.

The Moons of Saturn The Moons of Uranus Saturn has at least 47 moons. Titan is the largest moon of Saturn. It has an atmosphere 700 km thick composed of nitrogen. The Moons of Uranus Uranus has at least 27 moons. One smaller moon is called Miranda. It’s patchwork surface may have been caused by an impact that shattered the moon and caused it to reform.

The Moons of Neptune The Moon of Pluto Neptune has 13 known moons. Triton is the largest. Triton orbits in Neptune in retrograde. It is geologically active and has a thin atmosphere of nitrogen gas. The Moon of Pluto Charon has a period of revolution that is the same as Pluto’s period of rotation. So, one side of Pluto always faces Charon and if you were standing on Pluto, Charon would seem not to move!