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Comet Halley, officially designated 1P/Halley, more generally known as Halley's Comet after Edmond Halley, is the best-known and the brightest of the "short-period" comets from the Kuiper belt that visit the inner solar system in years or decades-long orbits rather than the millennial periods of comets from the Oort Cloud.

The most standard pronunciation of "Halley" is [hælɪ] ( IPA), to rhyme with "valley". The once-standard alternate pronunciation [heɪlɪ] (to rhyme with "Bailey") led to rock and roll singer Bill Haley naming his band Bill Haley & His Comets.

1 Early history

Having perceived that the elements of the comet of 1682 were nearly the same as those of two comets which had appeared in 1531 (observed by Petrus ApianusPetrus Apianus (real name Peter Bienewitz) ( April 16, 1495 April 21, 1557) was a German astronomer, cartographer and instrument maker. Apianus's Cosmographia (1524) was the most popular book of its time on astronomy and geography. He also published the f) and 1607Events April 25 Battle of Gibraltar Dutch fleet destroys anchored Spanish fleet April 26 English colonists make landfall at Cape Henry, Virginia, later moving up the James River to found Jamestown, the first permanent English settlement in North America. (observed by Johannes KeplerThis article is about Johannes Kepler the astronomer. For the planned planet-finding space telescope, see Kepler Space Mission. Johannes Kepler ( December 27, 1571 November 15, 1630), a key figure in the scientific revolution, was a German astronomer, mat in PragueStatistics Area:496 km² Population: 1,169,106 2001 Map Prague Praha in Czech) is the capital and largest city of the Czech Republic. Situated on the Vltava river in central Bohemia, it is home to approximately 1. 2 million inhabitants. It can be derived f), Halley concluded that all three comets were in fact the same object returning every 76 years. After a rough estimate of the perturbations the comet would sustain from the attraction of the planets, he predicted its return for 1757Events March 14 On-board the HMS Monarch Admiral John Byng is executed by firing squad for neglecting his duty. June 23 Indian Mutiny: Battle of Plassey 3000 British troops under Robert Clive defeat a 50,000 strong Indian army under Siraj-ud-Dawlah at Pla. Halley's prediction of the comet's return proved to be correct, although it was not seen until December 1758, and did not pass through its perihelion until March 1759Events January 11 In Philadelphia, Pennsylvania, the first American life insurance company is incorporated. January 13 The Tavora family is executed following the accusation of attempted regicide on Joseph I of Portugal January 15 The British Museum opens, the attraction of Jupiter and Saturn having caused, as was computed by Alexis Clairault previously to its return, a retardation of 618 days. Halley did not live to see the comet's return, having died in 1742.

Halley's calculations enabled the comet's earlier appearances to be found in the historical record:

• When the comet was observed in 1456, it passed very near to the Earth; its tail extended over 60° of the heavens, and its tail took the form of a sabre.
• In 1066, the comet was thought to be an omen: later that year Harold II of England died at the Battle of Hastings. It is shown on the Bayeux Tapestry, and the accounts which have been preserved represent it as having then appeared to be four times the size of Venus, and to have shone with a light equal to a fourth of that of the Moon.
• It is calculated that Comet Halley may have passed as close as 0.03 AU from Earth in the year 837.
• Some have suggested that the comet's appearance in 12 BC might explain the Biblical story of the Star of Bethlehem.