William Herschel Discovers Uranus
March 13, 1781 · Early Modern
On March 13, 1781, German-born British astronomer William Herschel observed a faint object in constellation Gemini that differed from surrounding stars. Initially believing it was a comet, Herschel tracked its slow movement over subsequent nights. After consultation with Astronomer Royal Nevil Maskelyne and other European astronomers, calculations revealed the object had a nearly circular orbit, confirming it was a previously unknown planet. This discovery doubled the known size of the solar system, making Uranus the first planet discovered using a telescope. Herschel originally named it 'Georgium Sidus' after King George III, but 'Uranus' was later adopted internationally.
Key Figures
King George IIIWilliam HerschelNevil Maskelyne
Locations
Bath
Topics
astronomyplanetsheliocentrismsolar system
Connected Events — 4 Connections
Uranus orbital irregularities prompted Le Verrier and Adams to mathematically predict Neptune position Discovery of Neptune
Herschel's discovery of Uranus in 1781 established his reputation as a leading observational astronomer and demonstrated his skill in detecting subtle celestial motions, which directly enabled his subsequent analysis of stellar proper motions that led to determining the Sun's motion through space Herschel Determines the Sun's Motion Through Space
Uranus discovery brought Herschel fame and royal patronage, providing the resources and recognition that enabled his systematic star-counting surveys of the Milky Way William Herschel Maps the Milky Way Galaxy
Expanded the known size of the solar system in 1781, making stellar parallax measurements more urgent as astronomers sought to understand the scale relationship between planetary and stellar distances First Stellar Parallax Measurement
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