Callisto is one of the largest natural satellites orbiting Jupiter. It is characterized by a highly cratered, ancient surface, suggesting that its geological processes have been largely inactive for extended periods. Its distance from the gas giant has contributed to a relatively stable, though heavily impacted, surface that preserves a record of early bombardment history. The moon's orbit places it far from the main planetary body, and its composition is thought to involve a mantle of rock and an icy crust.