William Herschel was born in Hannover in Germany in 1738. As his father was a musician in the Hannover Guard his early life was devoted to music.
William followed in his father’s footsteps, becoming a musician in the Guard, but due to an impending invasion of Hannover by the French army his father sent him to England in 1757.
In England he changed his birth name, Wilhelm, to William and continued to devote his life to music, composing 24 symphonies.
It wouldn’t be until the early 1770’s that Herschel began to take an interest in astronomy. He engrossed himself in astronomical publications and associated with notable astronomers of the time.
Herschel began to observe the planets and stars but was frustrated with the inadequate telescopes that were available. As a result he constructed his own Newtonian reflecting telescope but on a much larger scale than anything that had been built before.
Herschel’s intention wasn’t to simply peer at local planets but to map the entire sky. He began cataloguing double stars, stars that appear very close to each other in the night sky. It was thought that all double stars were in fact extremely distant from each other and by observing their shifts as Earth orbited the sun their distance could be calculated. Herschel eventually realized that many double stars were not distant from each but in fact close and actually orbited around each other. Two stars that orbit each other are known as binaries and by the end of his life Herschel had discovered almost a thousand binary or multiple star systems.
During his observations of binary stars Herschel noticed what he thought at the time was a comet, further investigation of the object concluded that he had in fact discovered a new planet. Herschel named the new planet Georgium Sidus (Georges’s Star) after the then King of England. It would later be known as Uranus, the first planet to be discovered since the ancients discovered Mercury through Saturn.
In the late 18th century Herschel began investigating non-stellar objects, calling them nebulae. He catalogued the different varieties of these ‘nebulae’, discovering more than 2,000 of them, unknown to him was that many of these nebulae were in fact galaxies, a fact which wouldn’t be discovered until the 20th century.
Herschel went on to discover the moons Mimas and Enceladus, which orbited Saturn, and Titania and Oberon which orbited Uranus, with telescopes that he had built himself. He also proved that the entire solar system was moving through space, discovered infrared light and estimated that the Milky Way Galaxy was disc shaped.
William Herschel was a true genius and astronomical pioneer, advancing our understanding of the universe by an enormous amount. He may not be as well known in modern times as Galileo or Newton but his contribution to science is no less profound. Six years before his death he became Sir William Herschel after he was knighted in 1816, he died in 1822 aged 83.
