Astronomy: Discovery of Uranus by William Herschel in 1781 Before the discovery of Uranus by William Herschel the world knew about the five existing planets that were able to be observed by the naked eye. These planets are Mercury, Venus, Mars, Jupiter and Saturn. The earth was not considered in these planets because earth was previously thought to be the center of the universe where all celestial bodies revolved around it. William Herschel began at a young age to ponder the heavens and what was out there, he used small telescopes but was soon frustrated because of their lack of power to see much further than the naked eye. Herschel was motivated to build larger telescopic tools to look deeper into the cosmos. Because of Herschel motivation