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| name=1P/Halley | image= Giotto Mission . The nucleus is sunlit from the left, and several bright jets of gas and dust are visible.]] | discoverer=prehistoric; Named after Edmond Halley | discovery_date=1758 (first predicted perihelion) | designations=Halley's Comet, 1P (see perihelia) | epoch=2449400.5 ( February 17 , 1994 ) | semimajor=17.8 AU | perihelion=0.586 AU | aphelion=35.1 AU | eccentricity=0.967 | period=75.3 A | inclination=162.3° | last_p= February 9 , 1986 | next_p= July 28 , 2061 }} ''See Halley's Comet (song) for the Phish song'' Comet Halley, officially designated '''1P/Halley''', more generally known as '''Halley's Comet''' after Edmond Halley , is a Comet that can be seen every 75-76 years. It is the most famous of all periodic comets, even though in every century many comets appear brighter and more spectacular. Halley's comet last appeared in the inner Solar System in 1986, and will appear again in the summer of 2061. The most standard pronunciation of "Halley" - and the pronunciation that the astronomer himself probably used - is ( IPA ), to rhyme with "valley". The once-standard alternate pronunciation [ (to rhyme with "Bailey") led to Rock And Roll Singer Bill Haley naming his band Bill Haley And The Comets . Edmond Halley's study Halley's Comet was the first to be recognized as periodic. Having perceived that the observed characteristics of the comet of 1682 were nearly the same as those of two comets which had appeared in 1531 (observed by Petrus Apianus ) and 1607 (observed by Johannes Kepler in Prague ), Halley concluded that all three comets were in fact the same object returning every 76 years (a period that has since been amended to every 75-76 years). After a rough estimate of the perturbations the comet would sustain from the attraction of the planets, he predicted its return for 1757. Halley's prediction of the comet's return proved to be correct, although it was not seen until 25 December 1758 by Johann Georg Palitzsch , a German farmer and amateur astronomer, and did not pass through its Perihelion until March 1759; the attraction of Jupiter and Saturn having caused a retardation of 618 days, as was computed by a team of three French mathematicians, Alexis Clairault , Joseph Lalande , and Nicole-Reine Lepaute , previous to its return. Halley did not live to see the comet's return, having died in 1742. Notable appearances Halley's calculations enabled the comet's earlier appearances to be found in the historical record. Early appearances tablet recording the appearance of Halley's comet in 164 BC.]] . ''ISTI MIRANT STELLA'' meaning ''they are watching the star''.]]
Recent history The most recent appearances have been in 1835, 1910 and 1986. Halley's Comet will next appear in 2061. 1910 The May 1910 approach was notable for several reasons: it was the first approach of which photographs exist, and the comet made a relatively close approach, making it a spectacular sight. Indeed, on 19 May , the comet Transited the Sun's disk, and the Earth actually passed through its tail. At the time, the comet's tail was known to contain poisonous Cyanogen gas. The popular media picked up this fact and, despite the pleas of astronomers, wove sensational tales of mass cyanide poisoning engulfing the planet. In reality, the gas is so diffuse that the world suffered no ill-effects from the passage through the tail. Many people who claim to remember seeing the 1910 apparition are in fact remembering a different comet, the Great Daylight Comet Of 1910 , which surpassed Halley in brilliance and was actually visible in broad daylight for a short time about four months before Halley made its appearance. 1986 The 1986 approach was the least favourable for Earth observers of all recorded passages of the comet throughout history: the comet did not achieve the spectacular brightness of some previous approaches, and with increased Light Pollution from urbanization, many people never saw the comet at all. Further, the comet appeared brightest when it was almost invisible from the northern hemisphere in March and April, prompting many amateur astronomers to travel to the southern hemisphere for a glimpse of the interloper. However, the development of space travel allowed scientists the opportunity to study a comet at close quarters, and several probes were launched to do so. Most spectacularly, the Giotto Space Probe , launched by the European Space Agency , made a close pass of the comet's nucleus. Other probes included the Soviet Union / France joint projects Vega 1 and Vega 2 , and two Japan ese probes, Suisei and Sakigake . The probes were unofficially known as the Halley Armada . It was Stephen Edberg (the serving as the Coordinator for Amateur Observations at NASA 's Jet Propulsion Laboratory ( JPL )) and Charles Morris who were the first to observe Comet Halley with the naked eye in its 1986 apparition. The comet was also observed from space by the International Cometary Explorer , which was in a solar orbit at the time. Originally International Sun-Earth Explorer 3 (ISEE-3), it was renamed and retooled after it was freed from its L1 Lagrangian Point location to observe comet 21P/Giacobini-Zinner . Two Space Shuttle missions--the ill-fated STS-51-L and STS-61-E--were scheduled to observe Comet Halley from Low Earth Orbit . 61-E, which would have been flown by '' Columbia '' in March 1986, would have carried the ASTRO-1 platform to study the comet, among other things. The ''Challenger'' disaster thwarted all such plans. ASTRO-1 would not fly until late 1990 on STS-35 . {Link without Title} The Soviet Union 's Salyut 7 space station was unoccupied during Halley's 1986 visit, and Mir , though launched during the visit, did not receive its first crew until later. Dates of perihelia Comet Halley returned / will return to Perihelion on the following dates. It is usually visible to the unaided eye for a few months around perihelion. The above table sets out the dates of perihelia and the Astronomical Designation for various Apparition s of Halley's Comet. For example, " 9 February 1986 (1P/1982 U1, 1986 III, 1982i)" indicates that for the perihelion on 9 February 1986 , Halley's Comet was the first period comet known (designated 1P) and this apparition was the first seen in "half-month" U (the first half of November) in 1982 (giving 1P/1982 U1); it was the third comet past perihelion in 1986 (1986 III); and it was the ninth comet spotted in 1982 ( Provisional Designation 1982i). Trivia
Halley's Comet in fiction
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