Herschel Discovers Uranus: Solar System Expands Beyond Saturn

William Herschel was surveying the night sky from his garden in Bath, England, on March 13, 1781, when he noticed a faint object that moved against the background stars. He initially reported it as a comet, but further observation revealed a nearly circular orbit characteristic of a planet. The mathematical astronomer Anders Johan Lexell calculated its distance at roughly 19 times the Earth-Sun distance, confirming it was far beyond Saturn. Herschel wanted to name it 'Georgium Sidus' after King George III, a suggestion that Continental astronomers rejected. The name Uranus, proposed by Johann Bode, eventually won acceptance. The discovery was the first new planet found since antiquity and effectively doubled the known size of the solar system. It also made Herschel famous overnight. George III appointed him Royal Astronomer with an annual salary of 200 pounds, freeing him from his career as a musician and allowing him to dedicate his life to astronomy. His sister Caroline, who assisted him throughout, became the first woman to discover a comet.