William Lassell (June 18, 1799 - October 5, 1880) was an English merchant and astronomer. He is remembered for his improvements to the reflecting telescope and his ensuing discoveries of four planetary satellites. In 1846 Lassell discovered Triton, the largest moon of Neptune, just 17 days after the discovery of Neptune itself by German astronomer Johann Gottfried Galle. In 1848 he independently co-discovered Hyperion, a moon of Saturn. In 1851 he discovered Ariel and Umbriel, two moons of Uranus. In 1855, he built a 48-inch telescope, which he installed in Malta because of the observing conditions that were better than in often-overcast England. On his return to the UK after several years in Malta he moved to Maidenhead and operated his 24-inch telescope in an observatory there. The 48-inch telescope was dismantled and was eventually scrapped. Lassell was a Fellow of the Royal Astronomical Society (FRAS) from 1839, won the Gold Medal of the Royal Astronomical Society in 1849, and served as its president for two years starting in 1870. | |
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