The Planet Uranus, number 7 in a set of 9 prints featuring the planets of our Solar System. Uranus is the seventh planet from the Sun. It is named after the ancient Greek deity of the sky Uranus, the father of Cronus (Saturn) and grandfather of Zeus (Jupiter). Though it is visible to the naked eye like the five classical planets, it was never recognized as a planet by ancient observers. Sir William Herschel announced its discovery on March 13, 1781, expanding the known boundaries of the Solar System for the first time in modern history. Uranus was also the first planet discovered with a telescope.