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Ices in the Solar System

Ices in the Solar System
Ices in the Solar System Not all ice is water. Not all water is on Earth. These are the first insights to come from studying the various ices in our solar system. Comets, such as Hale-Bopp (inset), are made primarily of water ice, but frozen carbon dioxide often makes up a substantial part of a comet nucleus. The Martian north polar cap (3D background image, exaggerated vertically to show detail) is primarily frozen water, but the southern cap on Mars is mostly frozen carbon dioxide. The largest of Jupiter's moons, Ganymede (full disk), is bigger than the planet Mercury. Still, in composition, it is roughly half water ice, making it truly a giant snowball in space. Hale-Bopp image: Jerzy Giergielewicz; Mars: MSSS/NASA; Ganymede: JPL/NASA