Johann Gottfried Galle

Johann Gottfried Galle was a German astronomer working at the Berlin Observatory when, on 23 September 1846, he received coordinates from Urbain Le Verrier predicting the position of an unknown planet. With the help of student Heinrich Louis d'Arrest, Galle pointed his telescope at the spot that same night and identified Neptune within 1° of where Le Verrier said it would be. The discovery stood as a dramatic validation of celestial mechanics — mathematics had conjured a world into view. Born in Radis, Germany, on 9 June 1812, Galle lived to see the 20th century, dying on 10 July 1910, six dec…