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Lists Of Comets
Non-periodic comets are seen only once. They are usually on near-parabolic orbits that will not return to the vicinity of the Sun for thousands of years, if ever. Periodic comets usually have elongated elliptical orbits, and usually return to the vicinity of the Sun after a number of decades. The official names of non-periodic comets begin with a "C"; the names of periodic comets begin with "P" or a number followed by "P". Lost comets, Comets that have been lost or disappeared have names with a "D". Comets whose orbit has not been determined are designated with a "X" prefix. Lists * List of comets by type * List of comets visited by spacecraft * List of comets with no meaningful orbit * List of Great Comets * List of Halley-type comets * List of hyperbolic comets * List of long-period comets * List of near-parabolic comets * List of numbered comets * List of periodic comets See also * Lists of astronomical objects * Comet vintages External links Bright Comet ChroniclesCom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S0484
S, or s, is the nineteenth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''ess'' (pronounced ), plural ''esses''. History Origin Northwest Semitic šîn represented a voiceless postalveolar fricative (as in 'ip'). It originated most likely as a pictogram of a tooth () and represented the phoneme via the acrophonic principle. Ancient Greek did not have a phoneme, so the derived Greek letter sigma () came to represent the voiceless alveolar sibilant . While the letter shape Σ continues Phoenician ''šîn'', its name ''sigma'' is taken from the letter '' samekh'', while the shape and position of ''samekh'' but name of ''šîn'' is continued in the '' xi''. Within Greek, the name of ''sigma'' was influenced by its association with the Greek word (earlier ) "to hiss". The original name of the letter "sigma" may have been ''san'', but due to the compli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Hyperbolic Comets
This is a list of parabolic and hyperbolic comets in the Solar System. Many of these comets may come from the Oort cloud, or perhaps even have interstellar origin. The Oort Cloud is not gravitationally attracted enough to the Sun to form into a fairly thin disk, like the inner Solar System. Thus, comets originating from the Oort Cloud can come from roughly any orientation (inclination to the ecliptic), and many even have a retrograde orbit. By definition, a hyperbolic orbit means that the comet will only travel through the Solar System once, with the Sun acting as a gravitational slingshot, sending the comet hurtling out of the Solar System entirely unless its eccentricity is otherwise changed. Comets orbiting in this way still originate from the Solar System, however. Typically comets in the Oort Cloud are thought to have roughly circular orbits around the Sun, but their orbital velocity is so slow that they may easily be perturbed by passing stars and the galactic tide. Astr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet Vintages
Comet vintages are years during which an astronomical event, involving generally a "Great Comet", occurs prior to harvest. Throughout the history of wine, winemakers have attributed successful vintages and ideal weather conditions to the unexplained effects caused by the comets.''The New York Times'' archives (August 13, 1872)The Comet/ref> Some of the most heralded vintages in the last couple of centuries—such as the 1811, 1826, 1839, 1845, 1852, 1858, 1861, 1985, and 1989 vintages—have coincided with a notable appearance of a comet.G. Harding ''"A Wine Miscellany"'' pg 45–47, Clarkson Potter Publishing, New York 2005 There is no scientific basis for any effect of comets on viticulture, but the term nevertheless remains in use. The term "comet wine" is sometimes used in the wine world to describe a wine of exceptional quality in reference to the high reputation that comet vintages have. The 1811 comet vintage, coinciding with the appearance of the Great Comet of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lists Of Astronomical Objects
This is a list of lists, grouped by type of astronomical object. Solar System * List of Solar System objects * List of gravitationally rounded objects of the Solar System * List of Solar System objects most distant from the Sun * List of Solar System objects by size * Lists of geological features of the Solar System * List of natural satellites (moons) * Lists of small Solar System bodies * Lists of comets * List of meteor showers ; Minor planets * List of minor planets ** List of exceptional asteroids ** List of minor planet moons ** List of damocloids ** List of centaurs (small Solar System bodies) ** List of trans-Neptunian objects ** List of unnumbered minor planets ** List of dwarf planets ** List of possible dwarf planets Exoplanets and brown dwarfs * Lists of planets * Lists of exoplanets ** List of largest exoplanets * List of brown dwarfs Stars *Lists of stars **List of nearest stars and brown dwarfs **List of brightest stars **List of hottest stars **Lis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Periodic Comets
Periodic comets (also known as short-period comets) are comets with orbital periods of less than 200 years or that have been observed during more than a single perihelion passage (e.g. 153P/Ikeya–Zhang). "Periodic comet" is also sometimes used to mean any comet with a periodic orbit, even if greater than 200 years. Periodic comets receive a permanent number prefix usually after the second perihelion passage, which is why there are a number of unnumbered periodic comets, such as P/2005 T5 (Broughton). Comets that are not observed after a number of perihelion passages, or presumed to be destroyed, are given the D designation, and likewise comets given a periodic number and subsequently lost are given instead of , such as 3D/Biela or 5D/Brorsen. In nearly all cases, comets are named after their discoverers, but in a few cases such as 2P/Encke and 27P/Crommelin they were named for a person who calculated their orbits (the orbit computers). The long-term orbits of comets are ... [...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 lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Near-parabolic Comets
The following is a list of comets with a very high eccentricity (generally 0.99 or higher) and a period of over 1,000 years that do not quite have a high enough velocity to escape the Solar System. Often, these comets, due to their extreme semimajor axes and eccentricity, will have small orbital interactions with planets and minor planets, most often ending up with the comets fluctuating significantly in their orbital path. These comets probably come from the Oort cloud, a cloud of comets orbiting the Sun from ~10,000 to roughly 50,000 AU. The actual orbit of these comets significantly differs from the provided coordinates. A Solar System barycentric orbit computed at an epoch when the object is located beyond all the planets is a more accurate measurement of its long-term orbit. List of near-parabolic comets See also * List of comets by type * List of Halley-type comets * List of hyperbolic comets * List of long-period comets * List of numbered comets This is a list of pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Long-period Comets
The following list is of comets with very long orbital periods, defined as between 200 and 1000 years. These comets come from the Kuiper belt and scattered disk, beyond the orbit of Pluto, with possible origins in the Oort cloud for many. For comets with an orbital period of over 1000 years, see the List of near-parabolic comets. See also * List of comets by type * List of hyperbolic comets * List of periodic comets * 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 ... References {{Portal bar, Astronomy, Stars, Spaceflight, Outer space, Solar System long period comets ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Halley-type Comets
The following is a list of Halley-type comets (HTCs), which are periodic comets with an orbital period between 20 and 200 years, often appearing only once or twice within one's lifetime. The majority come from between the orbits of Saturn and Neptune. Due to the nature of their orbits, they can be perturbed by the giant planets and sent into orbits too far from the Sun to outgas, and vice versa. Minor planets in comet-like orbits similar to HTCs that never come close enough to the Sun to outgas are called centaurs. HTCs are named after the first discovered member, and the first discovered periodic comet, Halley's Comet, which orbits the Sun in about 75 years, and passing as far as the orbit of Neptune. Most of the comets that have a period between 20 and 200 years (making them HTCs based on the classical definition) are actually officially classified as either Jupiter-family comets (JFCs) or Chiron-type comets (CTCs), based on their Jupiter Tisserand's parameter (TJupiter). Although ... [...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 mill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Great Comets
A great comet is a comet that becomes exceptionally bright. There is no official definition; often the term is attached to comets such as Halley's Comet, which during certain appearances are bright enough to be noticed by casual observers who are not looking for them, and become well known outside the astronomical community. Great comets appear at irregular, unpredictable intervals, on average about once per decade. Although comets are officially named after their discoverers, great comets are sometimes also referred to by the year in which they appeared great, using the formulation "The Great Comet of ...", followed by the year. Causes The vast majority of comets are never bright enough to be seen by the naked eye, and generally pass through the inner Solar System unseen by anyone except astronomers. However, occasionally a comet may brighten to naked eye visibility, and even more rarely it may become as bright as or brighter than the brightest stars. The requirements for thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Comets With No Meaningful Orbit
This is a list of comets designated with X/ prefix. The majority of these comets were discovered before the invention of the telescope in 1610, and as such there was nobody to plot the positions of the comets to a high enough precision to generate any meaningful orbit. Later comets, observed in the 17th century or later, either did not have enough observations, sometimes as few as one or two, or the comet disintegrated or moved out of a favorable location in the sky before it was possible to make more observations of it. References * Maik Meyer. Catalogue of Comet Discoveries External links * PDS PD, P.D., or Pd may refer to: Arts and media * ''People's Democracy'' (newspaper), weekly organ of the Communist Party of India (Marxist) * ''The Plain Dealer'', a Cleveland, Ohio, US newspaper * Post Diaspora, a time frame in the ''Honorverse'' ...br>Comet Catalog {{Portal bar, Astronomy, Stars, Spaceflight, Outer space, Solar System No meaningful orbit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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