in greek mythology, zeus places his son (the baby heracles) whose mother was a mortal woman on hera's breast while she is sleeping so that the baby will drink her divine milk and become immortal. however, hera wakes up while she is breastfeeding the baby and realizes she is nursing a baby she does not know. according to greek mythology, she then pushes the baby away and a stream of her milk sprays the night sky, making a faint band of light known as the milky way.