Quote:
Callisto (kə-lis'-toe, IPA: [kəˈlɪstoʊ]; Greek Καλλιστώ) is a moon of the planet Jupiter, discovered in 1610 by Galileo Galilei. It is the third-largest moon in the solar system, about the same size as the planet Mercury.
Callisto is named after Callisto, one of Zeus's many love interests in Greek mythology.
Although the name "Callisto" was suggested by Simon Marius soon after the moon's discovery, this name and the names of the other Galilean satellites fell into disfavour for a considerable time, and were not revived in common use until the mid-20th century. In much of the earlier astronomical literature, Callisto is simply referred to by its Roman numeral designation, Jupiter IV or as "the fourth satellite of Jupiter".
In scientific writing, the adjectival form of the name is usually Callistoan.
Callisto is one of the most heavily cratered satellites in the solar system. In fact, impact craters and associated concentric rings are about the only features to be found; there are no large callistoan mountains. This is probably due to the icy nature of its surface, with the largest craters and mountains being erased by the flow of the icy crust over geological time. Two enormous concentric ring impact basins are found on Callisto; Valhalla is the largest with a bright central region that is 600 kilometers in diameter and rings extending to 3000 kilometers in diameter, and the second-largest impact basin is Asgard measuring about 1600 kilometers in diameter. Another interesting feature is Gipul Catena, a long series of impact craters lined up in a straight line across Callisto's surface. This was probably caused by an object that was tidally disrupted as it passed close to Jupiter (much like Comet Shoemaker-Levy 9) before it impacted. Callisto's crust is thought to be approximately 4 billion years old, dating back almost to the formation of the solar system.
Callisto is named after Callisto, one of Zeus's many love interests in Greek mythology.
Although the name "Callisto" was suggested by Simon Marius soon after the moon's discovery, this name and the names of the other Galilean satellites fell into disfavour for a considerable time, and were not revived in common use until the mid-20th century. In much of the earlier astronomical literature, Callisto is simply referred to by its Roman numeral designation, Jupiter IV or as "the fourth satellite of Jupiter".
In scientific writing, the adjectival form of the name is usually Callistoan.
Callisto is one of the most heavily cratered satellites in the solar system. In fact, impact craters and associated concentric rings are about the only features to be found; there are no large callistoan mountains. This is probably due to the icy nature of its surface, with the largest craters and mountains being erased by the flow of the icy crust over geological time. Two enormous concentric ring impact basins are found on Callisto; Valhalla is the largest with a bright central region that is 600 kilometers in diameter and rings extending to 3000 kilometers in diameter, and the second-largest impact basin is Asgard measuring about 1600 kilometers in diameter. Another interesting feature is Gipul Catena, a long series of impact craters lined up in a straight line across Callisto's surface. This was probably caused by an object that was tidally disrupted as it passed close to Jupiter (much like Comet Shoemaker-Levy 9) before it impacted. Callisto's crust is thought to be approximately 4 billion years old, dating back almost to the formation of the solar system.
