William Lassell discovers Ariel and Umbriel, moons…
October 1851 CE
William Lassell discovers Ariel and Umbriel, moons of Uranus, on October 24. 1851
Lassel had made his fortune as a beer brewer, which enabled him to indulge his interest in astronomy.
He built an observatory at his house "Starfield" in West Derby, a suburb of Liverpool.
Here he has a 24-inch (610 mm) reflector telescope, for which he has pioneered the use of an equatorial mount for easy tracking of objects as the Earth rotates.
He ground and polished the mirror himself, using equipment he constructed.
The observatory will later (1854) be moved further out of Liverpool, to Bradstone.
In 1846 Lassell had discovered Triton, the largest moon of Neptune, just seventeen days after the discovery of Neptune itself by German astronomer Johann Gottfried Galle.
In 1848 he had independently co-discovered Hyperion, a moon of Saturn.