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List Of Comets By Type
This is a list of comets (bodies that travel in Elliptic orbit, elliptical, Parabolic trajectory, parabolic, and sometimes Hyperbolic trajectory, hyperbolic orbits and display a Comet tail, tail behind them) listed by type. Comets are sorted into four categories: List of periodic comets, periodic comets (e.g. Halley's Comet), List of non-periodic comets, non-periodic comets (e.g. Comet Hale–Bopp), comets with List of hyperbolic comets, no meaningful orbit (the X/1106 C1, Great Comet of 1106), and Lost comet, lost comets (5D/Brorsen), displayed as either P (periodic), C (non-periodic), X (no orbit), and D (lost). Many of the earlier comets to be observed in history are designated with an X or D due to not having the tools to measure a comet's orbit accurately and eventually losing it. X/1106 C1 (the Great Comet of 1106) is a good example. The orbital elements for the older non-periodic comets in the list assume that the comet has an Orbital eccentricity, eccentricity of roughly 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times Earth's diameter, while the tail may stretch beyond one astronomical unit. If sufficiently bright, a comet may be seen from Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures and religions. Comets usually have highly eccentric elliptical orbits, and they have a wide range of orbital periods, ranging from several years to potentially several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Numbered Comets
This is a list of periodic comets that were numbered by the Minor Planet Center after having been observed on at least two occasions. Their orbital periods vary from 3.2 to 366 years. there are 436 numbered comets (1P–436P), most of them being members of the Jupiter-family (JFC). There are also 31 Encke-type comets (ETCs), 14 Halley-type comets (HTCs), five Chiron-type comets (CTCs), and one long-period comet ( 153P). About a third of these bodies are also near-Earth comets (NECs). In addition, eight numbered comets are principally classified as minor planets – five main-belt comets, two centaurs (CEN), and one Apollo asteroid – and display characteristics of both an asteroid and a comet. Occasionally, comets will break up into multiple chunks, as volatiles coming off the comet and rotational forces may cause it to break into two or more pieces. An extreme example of this is 73P/Schwassmann–Wachmann, which broke into over 50 pieces during its 1995 perihelion. For a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits the Sun, from a maximum (aphelion) to a minimum ( perihelion) and back again once each year. The astronomical unit was originally conceived as the average of Earth's aphelion and perihelion; however, since 2012 it has been defined as exactly (see below for several conversions). The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oort Cloud
The Oort cloud (), sometimes called the Öpik–Oort cloud, first described in 1950 by the Dutch astronomer Jan Oort, is a theoretical concept of a cloud of predominantly icy planetesimals proposed to surround the Sun at distances ranging from 2,000 to 200,000 AU (0.03 to 3.2 light-years).The Oort cloud's outer limit is difficult to define as it varies over the millennia as different stars pass the Sun and thus is subject to variation. Estimates of its distance range from 50,000 to 200,000 au. It is divided into two regions: a disc-shaped inner Oort cloud (or Hills cloud) and a spherical outer Oort cloud. Both regions lie beyond the heliosphere and are in interstellar space. The Kuiper belt, the scattered disc and the detached objects, the other three reservoirs of trans-Neptunian objects, are less than one thousandth as far from the Sun as the Oort cloud. The outer limit of the Oort cloud defines the cosmographic boundary of the Solar System and the extent of the Sun' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kreutz Sungrazer
The Kreutz sungrazers ( ) are a family of sungrazing comets, characterized by orbits taking them extremely close to the Sun at perihelion. They are believed to be fragments of one large comet that broke up several centuries ago and are named for German astronomer Heinrich Kreutz, who first demonstrated that they were related. A Kreutz sungrazers's aphelion is about from the Sun; these sungrazers make their way from the distant outer Solar System from a patch in the sky in Canis Major, to the inner Solar System, to their perihelion point near the Sun, and then leave the inner Solar System in their return trip to their aphelion. Several members of the Kreutz family have become great comets, occasionally visible near the Sun in the daytime sky. The most recent of these was Comet Ikeya–Seki in 1965, which may have been one of the brightest comets in the last millennium. It has been suggested that another cluster of bright Kreutz system comets may begin to arrive in the inner Sola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interstellar Comet
An interstellar object is an astronomical object (such as an asteroid, a comet, or a rogue planet, but not a star) in interstellar space that is not gravitationally bound to a star. This term can also be applied to an object that is on an interstellar trajectory but is temporarily passing close to a star, such as certain asteroids and comets (including exocomets). In the latter case, the object may be called an interstellar interloper. The first interstellar objects discovered were rogue planets, planets ejected from their original stellar system (e.g., OTS 44 or Cha 110913−773444), though they are difficult to distinguish from sub-brown dwarfs, planet-mass objects that formed in interstellar space as stars do. The first interstellar object which was discovered traveling through our Solar System was 1I/ʻOumuamua in 2017. The second was 2I/Borisov in 2019. They both possess significant hyperbolic excess velocity, indicating they did not originate in the Solar System. Earlier, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Naming Conventions
In ancient times, only the Sun and Moon, a few stars, and the most easily visible planets had names. Over the last few hundred years, the number of identified astronomical objects has risen from hundreds to over a billion, and more are discovered every year. Astronomers need to be able to assign systematic designations to unambiguously identify all of these objects, and at the same time give names to the most interesting objects, and where relevant, features of those objects. The International Astronomical Union (IAU) is the recognized authority in astronomy for assigning designations to celestial bodies such as stars, planets, and minor planets, including any surface features on them. In response to the need for unambiguous names for astronomical objects, it has created a number of systematic naming systems for objects of various sorts. Stars There are no more than a few thousand stars that appear sufficiently bright in Earth's sky to be visible to the naked eye. This repres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1P/Halley
Halley's Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–79 years. Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and thus the only naked-eye comet that can appear twice in a human lifetime. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. Halley's periodic returns to the inner Solar System have been observed and recorded by astronomers around the world since at least 240 BC. But it was not until 1705 that the English astronomer Edmond Halley understood that these appearances were reappearances of the same comet. As a result of this discovery, the comet is named after Halley. During its 1986 visit to the inner Solar System, Halley's Comet became the first comet to be observed in detail by spacecraft, providing the first observational data on the structure of a comet nucleus and the mechanism of coma and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edmond Halley
Edmond (or Edmund) Halley (; – ) was an English astronomer, mathematician and physicist. He was the second Astronomer Royal in Britain, succeeding John Flamsteed in 1720. From an observatory he constructed on Saint Helena in 1676–77, Halley catalogued the southern celestial hemisphere and recorded a transit of Mercury across the Sun. He realised that a similar transit of Venus could be used to determine the distances between Earth, Venus, and the Sun. Upon his return to England, he was made a fellow of the Royal Society, and with the help of King Charles II, was granted a master's degree from Oxford. Halley encouraged and helped fund the publication of Isaac Newton's influential ''Philosophiæ Naturalis Principia Mathematica'' (1687). From observations Halley made in September 1682, he used Newton's laws of motion to compute the periodicity of Halley's Comet in his 1705 ''Synopsis of the Astronomy of Comets''. It was named after him upon its predicted return in 1758, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsden Group
Marsden may refer to: Places Australia *Marsden, Queensland, a suburb in Logan City *Point Marsden, South Australia Canada *Marsden, Saskatchewan New Zealand *Marsden (New Zealand electorate) *Marsden Point *Marsden Bay, New Zealand United Kingdom *Marsden, Tyne and Wear *Marsden, West Yorkshire United States *Marsden Mounds an archaeological site in Louisiana, USA Other uses *Marsden (surname) *Marsden motion, a legal motion to replace an incompetent attorney *Marsden High School, in New South Wales, Australia *Marsden State High School, in Queensland, Australia *Samuel Marsden Collegiate School in Wellington, New Zealand *Marsden Rattler, otherwise known as the South Shields, Marsden, and Whitburn Colliery Railway The South Shields, Marsden, and Whitburn Colliery Railway was a Whitburn Coal Company built twin track branch railway line that ran along the North Sea coast in County Durham, England, from in South Shields to Whitburn Colliery at Marsden ... See also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kracht Group
"1.power, force, strength" # Low German giben name '' Crachto'' (High German: '' Krafto, Kraft'') , region = Netherlands, Northern Germany , languageorigin = Low German, Dutch , variant = Kraft, Krafft, Craft, Kraftmann, Kraftlos; Stark, Starker , footnotes = Kracht is surname of: * Christian Kracht (born 1966), a Swiss novelist and journalist * Felix Kracht (1912, Krefeld – 2002), a German engineer * Marion Kracht (born 1962, Munich), a German television actress * Torsten Kracht (born 1967), an East German-German football player * Lewis Kracht (1867–19??), a Swiss naturalist and dog-breeder See also * Kracht's theorem (Kracht formula) * ''Kracht'' (film), a 1990 Dutch drama film directed by Frouke Fokkema * ''Geeft ons kracht'', a 1920 Dutch silent film directed by Theo Frenkel Theodorus Maurita Frenkel (14 July 1871 – 20 September 1956) was a Dutch film director, actor and screenwriter of the silent era. He worked in Britain under the name Theo Bouwmeest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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