According to some writers, Zeus transformed himself into the figure of Artemis to lure Callisto and rape her. She became pregnant and when this was eventually discovered, she was expelled from Artemis’s group, after which a furious Hera, the wife of Zeus, transformed her into a bear. Later, just as she was about to be killed by her son when he was hunting, she was set among the stars as Ursa Major (“the Great Bear”). She was the bear-mother of the Arcadians, through her son Arcas by Zeus.
The fourth Galilean moon of Jupiter and a main belt asteroid are named after Callisto.