Callisto

Also, Kallisto. Classical Mythology. a nymph attendant on Artemis, punished for a love affair with Zeus by being changed into a bear and then transformed into stars as the constellation Ursa Major.
Astronomy. a large natural satellite of the planet Jupiter.
Historical Examples

A Journey in Other Worlds John Jacob Astor
Medal of Honor Dallas McCord Reynolds
The Classic Myths in English Literature and in Art (2nd ed.) (1911) Charles Mills Gayley
The Space Rover Edwin K. Sloat
Spacehounds of IPC Edward Elmer Smith
Empire Clifford Donald Simak
The Indulgence of Negu Mah Robert Andrew Arthur
Empire Clifford Donald Simak
Spacehounds of IPC Edward Elmer Smith
Astronomy of To-day Cecil G. Dolmage

noun
(Greek myth) a nymph who attracted the love of Zeus and was changed into a bear by Hera. Zeus then set her in the sky as the constellation Ursa Major
noun
the second largest (but faintest) of the four Galilean satellites of Jupiter, discovered in 1610 by Galileo. Approximate diameter: 4800 km; orbital radius: 1 883 000 km See also Galilean satellite
Callisto
(kə-lĭs’tō)
One of the four brightest satellites of Jupiter and the eighth in distance from the planet. Originally sighted by Galileo, it is the largest planetary satellite.