Sir William Herschel was a German-born British musician who became interested in astronomy later in life and built his own telescopes. It was with one of these instruments that Herschel discovered Uranus in 1781.
Herschel's discovery brought him many honours and allowed him to become a fulltime astronomer employed by George III. He then studied Saturn and discovered the moons Enceladus and Mimas. He also discovered Uranus's moons Oberon and Titania and studied and catalogued double stars and nebulae.
Photo: Portrait of William Herschel (Science Source/Science Photo Library)
The German-born British astronomer discovers Uranus.
The British astronomer concludes that Mars has seasons and inhabitants.
The 18th and early 19th century German-born British astronomer Sir William Herschel observed Mars's poles and noticed that they grew and shrank over the course of a year. Herschel correctly concluded that Mars has seasons, though he was wrong about Mars having inhabitants and a substantial atmosphere.
Patrick Moore describes the asteroid belt and its discovery.
Sir Patrick Moore explains how the asteroid belt between Mars and Jupiter was discovered. He also talks about Bode's Law, an 18th century empirical rule that was once thought to predict planets' orbits. It is now discredited by astronomers, including Sir Patrick.
Frederick William Herschel,KH, FRS (German: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a British astronomer and composer of German origin, and brother of Caroline Herschel. Born in the Electorate of Hanover, Herschel followed his father into the Military Band of Hanover, before migrating to Great Britain in 1757 at the age of nineteen.
Herschel constructed his first large telescope in 1774, after which he spent nine years carrying out sky surveys to investigate double stars. The resolving power of the Herschel telescopes revealed that the nebulae in the Messier catalogue were clusters of stars. Herschel published catalogues of nebulae in 1802 (2,500 objects) and in 1820 (5,000 objects). In the course of an observation on 13 March 1781 he realized that one celestial body he had observed was not a star, but a planet, Uranus. This was the first planet to be discovered since antiquity and Herschel became famous overnight. As a result of this discovery, George III appointed him Court Astronomer. He was elected as a Fellow of the Royal Society and grants were provided for the construction of new telescopes.
Herschel pioneered the use of astronomical spectrophotometry as a diagnostic tool, using prisms and temperature measuring equipment to measure the wavelength distribution of stellar spectra. Other work included an improved determination of the rotation period of Mars, the discovery that the Martian polar caps vary seasonally, the discovery of Titania and Oberon (moons of Uranus) and Enceladus and Mimas (moons of Saturn). In addition, Herschel discovered infrared radiation. Herschel was made a Knight of the Royal Guelphic Order in 1816. He was the first President of the Royal Astronomical Society when it was founded in 1820. He died in August 1822, and his work was continued by his only son, John Herschel.