The ancient Greeks used to explain things they couldn't understand with myths. That is how they explained the creation of the world, natural phenomena or destructions, the existance of powers that could surpass human nature, and, in general, everything that bothered them. That way, when they were looking at the sky and were observing all these stars, they would wonder what had caused these stars and constellations to exist. In fact, many myths have been created to explain the existence of stars. The story of Callisto is such a myth, created for the sake of two beautiful constellations, the Ursa Major and the Ursa Minor.
Callisto the bear
Callisto was the daughter of Lykaon, king of Arcadia and follower in hunting of goddess Artemis. Callisto, whose name means "the most beautiful", had sworn the goddess to remain virgin for all her life, as did all the companions of Artemis. However, one day, Zeus saw her and after many attempts, he seduced her.
Soon, the girl realized that she was pregnant but decided to keep it a secret from Artemis. Unfortunately, one day, while the goddess and her companions were getting ready to take their bath in a river, the pregnancy of Callisto was revealed. Artemis got so angry because the girl had violated her vow that she turned her into a bear, with the curse to live in the wild for the rest of her life and be killed by hunters one day.
Callisto the star
A few months later, Callisto the bear delivered a son, who was named Arcas, meaning "born by a bear". Zeus gave the baby boy to goddess Maia to raise him up. When he became a man, Arcas became the king of that land, who was named after his name, Arcadia. One day, while Arcas was hunting in the forest, he met a bear. It was his mother, Callisto. Arcas, who didn't know the truth about his mother, was getting ready to throw a javelin and kill this great bear.
Zeus, from Mount Olympus, saw that tragedy coming and before the javelin hit Callisto, he turned both of them into constellations. According to the ancient Greeks, these are the Ursa Major and Ursa Minor, meaning Big and Small Bear in Latin. They are the representations of Callisto and her son, Arcas. These stars can be seen mostly in summer, when the sky is clear, at the north side of the horizon.