Johann Encke, Biography

      On September 23, 1791, Johann Encke was born in Hamburg, Germany. He went to school at Gelehrtenschule des Johanneums, a college preparatory school. After graduation he went on to study mathematics and astronomy at the University of Gottingen in 1811 under Carl Friedrich Gauss, but it did not last long. He soon enlisted in the Hanseatic Legion for the campaign of 1813-1814, and then became a lieutenant of artillery in the Prussian service in 1815.

After his stint in the military, he returned to Gottingen in 1816. Immediately following his return, he was appointed as the assistant to Benhardt von Lindenau in the Seeberg Observatory in Switzerland. It was at that observatory that he completed his investigation of the comet of 1680, and his discovery earned him a Cotta Prize in 1817, awarded by judged Gauss and Olbers. He also correctly assigned an orbit period of 71 years to the comet of 1812, which is now known as 12P/Pons-Brooks. And most importantly discovered the comet that now bears his name, Encke’s comet. In 1822 he was appointed director of the Seeberg Observatory.

Encke discovered the orbit of Encke’s comet following a suggestion by Jean-Louis Pons. Pons surmised that one of the three comets that passed in 1808 was the same one that he has discovered in 1805. So, under Pons’ suggestion, Encke began studying the orbital elements of this comet, which was at the time, groundbreaking. At the time when Encke was investigating this comet, all other known comets had orbital periods of at least seventy years, with an aphelion far beyond the orbit of Uranus. While Pons was suggesting one with a less than fifteen-year orbital period, which was unheard of. For instance, the most famous comet to fall under that category was Halley’s comet, with a seventy-six year orbital period.

            However, after calculations, it was discovered that the comet had an orbital period of only 3.3 years, which was miraculous in those days. This showed that Encke’s comet had an aphelion that was inside the orbit of Jupiter. Encke predicted its return for 1822, which fit the schedule of its orbital period.

            Encke sent his calculations and discovery to Gauss, Olbers, and Bessel. Gauss published the works immediately, and Encke became known as the discoverer of short periodic comets. And because of this, it was named Encke’s comet. It is unusually, one of the only comets who was not named after its discoverer, and instead after the one who calculated its orbit.

In 1824, because of his discovery, the Royal Astronomical Society in London presented him with a Gold Medal. It was in that same year that Encke married Amalie Becker, the daughter of a bookseller. The two later had three sons and two daughters. It was the following year that Encke was a Fellow of the Royal Society.

Some of Encke’s smaller achievements include: becoming new director of the Academy of Sciences, issuing four volumes of Astronomische Beobachtungen auf der Sternwarte zu Berlin, discovering the Encke Gap in the Rings of Saturn, becoming an astronomy professor at the University of Berlin, and being elected a member of the Royal Swedish Academy of Sciences.

On August 26, 1865 he passed away from a brain disease, but he remained the director of the observatory until the day he passed. He passed away in Spandua and is buried in a cemetery in the Kreuzberg section of Berlin.