Johann Franz Encke was a German astronomer. He worked on the calculation of the periods of comets and asteroids, measured the distance from the earth to the sun, and made observations of the planet Saturn.
Background
Encke was born on September 23, 1791, in Hamburg, Germany, where his father was the Pastor at the St. James' Church, Hamburg. He was the youngest of eight children, and at the time his father died when he was four, the family in straitened circumstances.
Education
Encke was educated at Hamburg and the University of Göttingen, where he worked under the direction of Carl Friedrich Gauss.
Career
In 1816 Encke became assistant at the Seeberg Observatory near Gotha, Germany, where he was made vice director in 1820 and director in 1822. In 1825 he was appointed professor of astronomy and director of the observatory of the University of Berlin. There he planned and supervised the construction of a new observatory, completed in 1835.
Besides the comet that bears his name, Encke is also known for his discovery of Encke’s Division, in the outermost ring of Saturn. From observations of the transits of Venus recorded in 1761 and 1769, he derived a value for the solar parallax (in effect, for the Sun’s distance from the Earth) that, at 8″. 57, is close to the presently accepted figure. He also established methods for calculating the orbits of minor planets and orbits of double stars
Achievements
Membership
He was a member of Royal Swedish Academy of Sciences, American Academy of Arts and Sciences.
Connections
In 1824 Encke married Amalie Becker daughter of author, bookseller and publisher Rudolph Zacharias Becker, the publisher of works from the Seeberg Observatory. They had three sons and two daughters.