Ouranos (Ancient Greek: Οὐρανός - "sky" or "heaven") is the personification of the sky in Greek mythology. He is the son and husband of the primordial goddess Gaia and father of the Titans, Hekatonkheires, and Elder Cyclopes. His Roman equivalent was Caelus, the husband of Terra, as Gaia was known to the Romans. The planet Uranus is named after him, as well as the radioactive chemical element uranium.