William Herschel

Born on November 15, 1738, in Hanover, William Herschel was trained as a military musician and oboist. Moving to England in 1757, he became a renowned organist, composer, and conductor in Bath. Herschel's passion for music led him into mathematical harmonics and thence to astronomy. Dissatisfied with commercial telescopes, Herschel taught himself optical glass-grinding and speculum metal casting, building the finest, most powerful reflecting telescopes of the 18th century with the vital assistance of his sister and scientific partner Caroline Herschel. On the night of March 13, 1781, while conducting a systematic survey of the night sky from his garden in Bath, Herschel discovered an uncharted celestial object that proved to be Uranus—the first planet discovered since antiquity, instantly doubling the known diameter of the Solar System. Appointed Court Astronomer to King George III, Herschel constructed his colossal '40-foot telescope' (1.2-meter aperture) at Slough. Over decades of celestial surveying, Herschel and Caroline cataloged more than 2,500 nebulae and star clusters, discovered two moons of Saturn (Enceladus and Mimas) and two of Uranus (Titania and Oberon). In 1800, while passing sunlight through prisms and measuring temperatures beyond the red end of the spectrum, Herschel discovered invisible 'calorific rays'—the first discovery of infrared radiation. He died on August 25, 1822, as the pioneer of observational deep-sky cosmology.