Johann Franz Encke
Johann Franz Encke was a German
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

. Among his activities, he worked on the calculation of the periods of comets and asteroids, measured the distance from the earth to the sun, and made observations on the planet Saturn.


Encke was born in Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

, where his father was a clergyman, and educated at the Gelehrtenschule des Johanneums
Gelehrtenschule des Johanneums
The Gelehrtenschule des Johanneums is a Gymnasium in Hamburg, Germany. It is Hamburg's oldest school and was founded in 1529 by Johannes Bugenhagen. The school's motto is The Future needs a Heritage...

. He studied mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

 and astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 from 1811 at the University of Göttingen under Carl Friedrich Gauss
Carl Friedrich Gauss
Johann Carl Friedrich Gauss was a German mathematician and scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics.Sometimes referred to as the Princeps mathematicorum...

; but he enlisted in the Hanseatic Legion
Hanseatic Legion
The Hanseatic Legion was a military unit, first formed of a group of citizens of Hamburg. They had met in 1813 on the instigation of General Friedrich Karl von Tettenborn, in order to fight in the War of the Sixth Coalition...

 for the campaign of 1813–1814, and became lieutenant of artillery in the Prussian army
Prussian Army
The Royal Prussian Army was the army of the Kingdom of Prussia. It was vital to the development of Brandenburg-Prussia as a European power.The Prussian Army had its roots in the meager mercenary forces of Brandenburg during the Thirty Years' War...

 in 1815.

Having returned to Göttingen in 1816, he was at once appointed by Bernhardt von Lindenau as his assistant in the observatory of Seeberg
Gotha Observatory
Gotha Observatory was a German astronomical observatory located on Seeberg hill near Gotha, Thuringia, Germany...

 near Gotha
Gotha (town)
Gotha is a town in Thuringia, within the central core of Germany. It is the capital of the district of Gotha.- History :The town has existed at least since the 8th century, when it was mentioned in a document signed by Charlemagne as Villa Gotaha . Its importance derives from having been chosen in...

. There he completed his investigation of the comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...

 of 1680, for which the Cotta prize was awarded to him in 1817 by judges Gauss and Olbers; he correctly assigned a period of 71 years to the comet of 1812. That comet is now called 12P/Pons-Brooks
12P/Pons–Brooks is a periodic comet with a period of 71 years. The comet was suggested by Carl Sagan as the spectacular comet seen by the Chinese in 1486 BCE which, according to historical researcher Graham Phillips, might have inspired the rise of a number of monotheistic religions around the...


Following a suggestion by Jean-Louis Pons
Jean-Louis Pons
Jean-Louis Pons was a French astronomer.Despite humble beginnings and being self-taught, he went on to become the greatest visual comet discoverer of all time: between 1801 and 1827 Pons discovered thirty-seven comets, more than any other person in history.- Early life :Pons was born at Peyre,...

, who suspected one of the three comets discovered in 1818 to be the same one already discovered by him in 1805, Encke began to calculate the orbital elements
Orbital elements
Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are generally considered in classical two-body systems, where a Kepler orbit is used...

 of this comet. At this time, all the known comets had an orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...

 of seventy years and more, with an aphelion far beyond the orbit of Uranus
Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus , the father of Cronus and grandfather of Zeus...

. The most famous comet of this family was Comet Halley
Comet Halley
Halley's Comet or Comet Halley is the best-known of the short-period comets, and is visible from Earth every 75 to 76 years. Halley is the only short-period comet that is clearly visible to the naked eye from Earth, and thus the only naked-eye comet that might appear twice in a human lifetime...

 with its period of seventy-six years. So the orbit of the comet discovered by Pons was a sensation, because his orbit was found to have a period of 3.3 years, so that the aphelion had to be within the orbit of Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

. Encke predicted its return for 1822, but this return was observable only from the southern hemisphere and was seen by Carl Ludwig Christian Rümker
Carl Ludwig Christian Rümker
Carl Ludwig Christian Rümker was a German astronomer. In German, his name is spelt Karl Ludwig Christian Rümker; he was also known as Charles Rümker, Charles Rumker, Charles Luis Rumker, Christian Carl Ludwig Rümker and Dr...

 in Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. The comet was also identified with the one seen by Pierre Méchain
Pierre Méchain
Pierre François André Méchain was a French astronomer and surveyor who, with Charles Messier, was a major contributor to the early study of deep sky objects and comets.-Life:...

 in 1786 and by Caroline Herschel
Caroline Herschel
Caroline Lucretia Herschel was a German-British astronomer, the sister of astronomer Sir Friedrich Wilhelm Herschel with whom she worked throughout both of their careers. Her most significant contribution to astronomy was the discovery of several comets and in particular the periodic comet...

 in 1795.

Encke sent his calculations as a note to Gauss, Olbers, and Bessel
Friedrich Bessel
-References:* John Frederick William Herschel, A brief notice of the life, researches, and discoveries of Friedrich Wilhelm Bessel, London: Barclay, 1847 -External links:...

. His former mathematics professor published this note and Encke became famous as the discoverer of the short periodic comets. The first object of this family, the Encke comet, was named after him and so it is one of the few comets not named after the discoverer, but after the one who calculated the orbit. Later this comet was identified as the origin of the Taurids
The Taurids are an annual meteor shower associated with the comet Encke. They are named after their radiant point in the constellation Taurus, where they are seen to come from in the sky...

 meteor shower
Meteor shower
A meteor shower is a celestial event in which a number of meteors are observed to radiate from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller...


The importance of the predicted return based on the calculation by Encke was rewarded by the Royal Astronomical Society
Royal Astronomical Society
The Royal Astronomical Society is a learned society that began as the Astronomical Society of London in 1820 to support astronomical research . It became the Royal Astronomical Society in 1831 on receiving its Royal Charter from William IV...

 in London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 by presenting their Gold Medal
Gold Medal of the Royal Astronomical Society
-History:In the early years, more than one medal was often awarded in a year, but by 1833 only one medal was being awarded per year. This caused a problem when Neptune was discovered in 1846, because many felt an award should jointly be made to John Couch Adams and Urbain Le Verrier...

 to him in 1824. In this year Encke married Amalie Becker (1787–1879), daughter of a bookseller. They had three sons and two daughters. In 1825 he was elected a Fellow of the Royal Society.

Eight masterly treatises on the comet's movements were published by him in the Berliner Abhandlungen (1829–1859). From a fresh discussion of the transits of Venus
Transit of Venus
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and Earth, becoming visible against the solar disk. During a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun...

 in 1761 and 1769 he deduced a solar parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...

 of 8.57 arcsecond. This and the corresponding distance to the sun were long accepted as authoritative. His results were published in two separate tracts, entitled Die Entfernung der Sonne (The distance to the sun, 1822-1824).

In 1822 he became director of the Seeberg
Seeberg is a municipality in the Oberaargau administrative district in the canton of Bern in Switzerland.-Geography:Seeberg has an area of . Of this area, 58.8% is used for agricultural purposes, while 34% is forested...

 observatory, and in 1825 was promoted to a corresponding position at Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, where a new observatory
Berlin Observatory
The Berlin Observatory is a series of observatories and related organizations in and around the city of Berlin in Germany, starting from the 18th century...

, built under his superintendence and with the support of Alexander von Humboldt
Alexander von Humboldt
Friedrich Wilhelm Heinrich Alexander Freiherr von Humboldt was a German naturalist and explorer, and the younger brother of the Prussian minister, philosopher and linguist Wilhelm von Humboldt...

 and King Frederick William III of Prussia
Frederick William III of Prussia
Frederick William III was king of Prussia from 1797 to 1840. He was in personal union the sovereign prince of the Principality of Neuchâtel .-Early life:...

, was inaugurated in 1835. Mostly on the recommendation of Bessel, Encke became director of the new observatory and secretary of the Academy of Sciences
Prussian Academy of Sciences
The Prussian Academy of Sciences was an academy established in Berlin on 11 July 1700, four years after the Akademie der Künste or "Arts Academy", to which "Berlin Academy" may also refer.-Origins:...


He directed the preparation of the star maps of the Academy (1830–1859); beginning in 1830, he edited and greatly improved the Astronomisches Jahrbuch; and he issued four volumes of the Astronomische Beobachtungen auf der Sternwarte zu Berlin (Observations of the Berlin observatory, 1840–1857). Within the following time Encke was involved in the discovery and orbital parameter determination of other short periodic comets and asteroids.

In 1837, Encke described a broad variation in the brightness of the A Ring of Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...

. The Encke Gap was later named in honor of his observations of Saturn's rings.

In 1844, Encke became professor for astronomy at the University of Berlin
Humboldt University of Berlin
The Humboldt University of Berlin is Berlin's oldest university, founded in 1810 as the University of Berlin by the liberal Prussian educational reformer and linguist Wilhelm von Humboldt, whose university model has strongly influenced other European and Western universities...

. Much labor was bestowed by him upon facilitating the computation of the movements of the asteroids. With this end in view he expounded to the Berlin Academy in 1849 a mode of determining an elliptic orbit
Elliptic orbit
In astrodynamics or celestial mechanics an elliptic orbit is a Kepler orbit with the eccentricity less than 1; this includes the special case of a circular orbit, with eccentricity equal to zero. In a stricter sense, it is a Kepler orbit with the eccentricity greater than 0 and less than 1 . In a...

 from three observations, and communicated to that body in 1851 a new method of calculating planetary perturbations by means of rectangular coordinates (republished in W. Ostwald's Klassiker der exacten Wissenschaften, No. 141, 1903).

Encke visited England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 in 1840. He was elected a foreign member of the Royal Swedish Academy of Sciences
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...

 in 1836. Incipient brain-disease compelled him to withdraw from official life in November 1863. He still was director of the Berlin observatory until his death on 26 August 1865 in Spandau
Spandau is the fifth of the twelve boroughs of Berlin. It is the fourth largest and westernmost borough, situated at the confluence of the Havel and Spree rivers and along the western bank of the Havel, but the least populated.-Overview:...

. His successor was Wilhelm Julius Foerster
Wilhelm Julius Foerster
Wilhelm Julius Foerster was a German astronomer, father of the pacifist and ethicist Friedrich Wilhelm Foerster. His name can also be written Förster, but is usually written "Foerster" even in most German sources where 'ö' is otherwise used in the text.A native of Grünberg, Silesia, he worked as...


He contributed extensively to the periodical literature of astronomy.

Encke's grave is preserved at a cemetery in the Kreuzberg
Kreuzberg, a part of the combined Friedrichshain-Kreuzberg borough located south of Mitte since 2001, is one of the best-known areas of Berlin...

 section of Berlin, the Friedhof II der Jerusalems- und Neuen Kirchengemeinde (Cemetery No. II of the congregations of Jerusalem's Church
Jerusalem's Church
Jerusalem's Church is one of the churches of the Evangelical Congregation in the Friedrichstadt , a member of the Protestant umbrella organisation Evangelical Church of Berlin-Brandenburg-Silesian Upper Lusatia. The present church building is located in Berlin, borough Friedrichshain-Kreuzberg, in...

 and New Church
Deutscher Dom
Deutscher Dom is the colloquial naming for the New Church located in Berlin on the Gendarmenmarkt across from Französischer Dom . Its parish comprised the northern part of the then new quarter of Friedrichstadt, which until then belonged to the parish of the congregations of Jerusalem's Church...

) (entrance: opposite to 58-60, Zossener Str.;61, Baruther Street only for vehicles of the cemetery). His grave is close to that of the mathematician Carl Gustav Jacob Jacobi.


  • Twice, in 1824 and 1830, the recipient of the Gold Medal of the Royal Astronomical Society
    Gold Medal of the Royal Astronomical Society
    -History:In the early years, more than one medal was often awarded in a year, but by 1833 only one medal was being awarded per year. This caused a problem when Neptune was discovered in 1846, because many felt an award should jointly be made to John Couch Adams and Urbain Le Verrier...

  • The crater Encke
    Encke (crater)
    Encke is a lunar crater that is located on the western edge of the Mare Insularum, to the south-southeast of the crater Kepler. The small crater Kunowsky lies to the east-southeast on the mare....

     on the Moon
    The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

     is named after him.
  • The asteroid
    Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

     9134 Encke
    9134 Encke
    9134 Encke is an asteroid-belt asteroid discovered on 24 September 1960 by Cornelis Johannes van Houten and Ingrid van Houten-Groeneveld at Leiden University, on photographic plates from the Palomar Observatory....

     is named in his honour.
  • The Encke gap of Saturn's rings is named after him.
  • The Comet Encke
    Comet Encke
    Comet Encke or Encke's Comet is a periodic comet that completes an orbit of the Sun once every three years — the shortest period of any known comet...

     is named after him for his calculation of its orbit.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.