Galle, Johann Gottfried 1812-1910
German astronomer

Born in Pabsthaus, near Wittenberg, and educated at Berlin University, he graduated in mathematics and physics in 1833. He taught for two years in a school before being invited by Johann Encke to become his assistant at the newly-established Berlin Observatory. After 16 years in this post he became director of the observatory at Breslau (now Wrojaw, Poland, 1851-91). He took a special interest in comets, discovered three new ones and for many years computed ephemerides of comets and minor planets for the Astronomisches Jahrbuch. His most dramatic discovery, made in Berlin, was of the planet Neptune, whose existence had been theoretically predicted and whose expected position had been calculated by Urbain Leverrier. In 1872 he proposed the use of asteroids rather than regular planets for determinations of the solar parallax, a suggestion which bore fruit in a successful international campaign (1888-89). The method was last used during the closest approach of the minor planet Eros in 1930-31.