Callisto is a Latinized form of Kallisto, an Ancient Greek name. It is derived from the Greek word kallistos meaning "most beautiful", a superlative of kalos ("beautiful"). In Greek mythology, Kallisto was a nymph and a companion of the goddess Artemis. She was loved by Zeus and was transformed into a she-bear by the jealous Hera. According to myth, Zeus later placed her in the sky as the constellation Ursa Major (the Great Bear). The name was also used as a personal name in ancient Greece.Astronomical SignificanceCallisto is the name of one of Jupiter's largest moons, discovered in 1610 by Galileo Galilei. It is the third-largest moon in the solar system and is named after the mythological nymph. The naming of Jupiter's moons follows a tradition of using mythological figures associated with Zeus (the Greek equivalent of Jupiter).Related NamesThe name has several variants across languages. Kallisto is the original Ancient Greek form, while Calista is a Spanish variant. These forms share the same etymological root and mythological background.Meaning: "most beautiful"Origin: GreekType: First nameUsage: GreekSymbolism: Moon of Jupiter, constellation Ursa Major