Ganymede (moon) Ganymede. By definition, Anat is at 128° longitude. The 0° longitude directly faces Jupiter, and unless stated otherwise longitude increases toward the west. Ganymede appears to be fully differentiated, with an internal structure consisting of an iron-sulfide–iron core, a silicate mantle and outer layers of water ice and liquid water. The precise thicknesses of the different layers in the interior of Ganymede depend on the assumed composition of silicates (fraction of olivine and pyroxene) and amount of sulfur in the core. Ganymede has the lowest moment of inertia factor, 0.31, among the solid Solar System bodies. This is a consequence
Triton (moon) more than 99.5% of all the mass known to orbit Neptune, including the planet's rings and thirteen other known moons, and is also more massive than all known moons in the Solar System smaller than itself combined. Also, with a diameter 5.5% that of Neptune, it is the largest moon of a gas giant relative to its planet in terms of diameter, although Titan is bigger relative to Saturn in terms of mass. It has a radius, density (2.061 g/cm), temperature and chemical composition similar to those of Pluto. Triton's surface is covered with a transparent layer of annealed frozen