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Plutinos
In astronomy, the plutinos are a dynamical group of trans-Neptunian objects that orbit in 2:3 mean-motion resonance with Neptune. This means that for every two orbits a plutino makes, Neptune orbits three times. The dwarf planet Pluto is the largest member as well as the namesake of this group. The next largest members are , , and . Plutinos are named after mythological creatures associated with the underworld. Plutinos form the inner part of the Kuiper belt and represent about a quarter of the known Kuiper belt objects. They are also the most populous known class of resonant trans-Neptunian objects ''(also see adjunct box with hierarchical listing)''. The first plutino after Pluto itself, (385185) 1993 RO, was discovered on September 16, 1993. Orbits Origin It is thought that the objects that are currently in mean orbital resonances with Neptune initially followed a variety of independent heliocentric paths. As Neptune migrated outward early in the Solar System's hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plutino Distributions And Sizes
In astronomy, the plutinos are a List of minor-planet groups, dynamical group of trans-Neptunian objects that orbit in 2:3 orbital resonance, mean-motion resonance with Neptune. This means that for every two orbits a plutino makes, Neptune orbits three times. The dwarf planet Pluto is the largest member as well as the namesake of this group. The next largest members are , , and . Plutinos Astronomical naming conventions#Minor planets, are named after mythological creatures associated with the underworld. Plutinos form the inner part of the Kuiper belt and represent about a quarter of the known Kuiper belt objects. They are also the most populous known class of resonant trans-Neptunian objects ''(also see adjunct box with hierarchical listing)''. The first plutino after Pluto itself, (385185) 1993 RO, was discovered on September 16, 1993. Orbits Origin It is thought that the objects that are currently in mean orbital resonances with Neptune initially followed a variety of i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest known trans-Neptunian object by volume, by a small margin, but is slightly less massive than Eris. Like other Kuiper belt objects, Pluto is made primarily of ice and rock and is much smaller than the inner planets. Compared to Earth's moon, Pluto has only one sixth its mass and one third its volume. Pluto has a moderately eccentric and inclined orbit, ranging from from the Sun. Light from the Sun takes 5.5 hours to reach Pluto at its average distance (). Pluto's eccentric orbit periodically brings it closer to the Sun than Neptune, but a stable orbital resonance prevents them from colliding. Pluto has five known moons: Charon, the largest, whose diameter is just over half that of Pluto; Styx; Nix; Kerberos; and Hydra. Pluto and C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Kuiper Belt Object
A classical Kuiper belt object, also called a cubewano ( "QB1-o"), is a low-eccentricity Kuiper belt object (KBO) that orbits beyond Neptune and is not controlled by an orbital resonance with Neptune. Cubewanos have orbits with semi-major axes in the 40–50 AU range and, unlike Pluto, do not cross Neptune's orbit. That is, they have low-eccentricity and sometimes low-inclination orbits like the classical planets. The name "cubewano" derives from the first trans-Neptunian object (TNO) found after Pluto and Charon: 15760 Albion, which until January 2018 had only the provisional designation (15760) 1992 QB1. Similar objects found later were often called "QB1-o's", or "cubewanos", after this object, though the term "classical" is much more frequently used in the scientific literature. Objects identified as cubewanos include: * 15760 Albion (aka 1992 QB1 and gave rise to term 'Cubewano') * 136472 Makemake, the largest known cubewano and a dwarf planet * 50000 Quaoar an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resonant Trans-Neptunian Object
In astronomy, a resonant trans-Neptunian object is a trans-Neptunian object (TNO) in mean-motion orbital resonance with Neptune. The orbital periods of the resonant objects are in a simple integer relations with the period of Neptune, e.g. 1:2, 2:3, etc. Resonant TNOs can be either part of the main Kuiper belt population, or the more distant scattered disc population. Distribution The diagram illustrates the distribution of the known trans-Neptunian objects. Resonant objects are plotted in red. Orbital resonances with Neptune are marked with vertical bars: 1:1 marks the position of Neptune's orbit and its trojans; 2:3 marks the orbit of Pluto and plutinos; and 1:2, 2:5, etc. mark a number of smaller families. The designation ''2:3'' or ''3:2'' both refer to the same resonance for TNOs. There is no ambiguity, because TNOs have, by definition, periods longer than Neptune's. The usage depends on the author and the field of research. Origin Detailed analytical and numerical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kuiper Belt Object
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia, and water. The Kuiper belt is home to most of the objects that astronomers generally accept as dwarf planets: Orcus, Pluto, Haumea, Quaoar, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region. The Kuiper belt was named after Dutch astronomer Gerard Kuiper, although he did not predict its existence. In 1992, minor planet (15760) Albi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cubewano
A classical Kuiper belt object, also called a cubewano ( "QB1-o"), is a low-eccentricity Kuiper belt object (KBO) that orbits beyond Neptune and is not controlled by an orbital resonance with Neptune. Cubewanos have orbits with semi-major axes in the 40–50 AU range and, unlike Pluto, do not cross Neptune's orbit. That is, they have low-eccentricity and sometimes low-inclination orbits like the classical planets. The name "cubewano" derives from the first trans-Neptunian object (TNO) found after Pluto and Charon: 15760 Albion, which until January 2018 had only the provisional designation (15760) 1992 QB1. Similar objects found later were often called "QB1-o's", or "cubewanos", after this object, though the term "classical" is much more frequently used in the scientific literature. Objects identified as cubewanos include: * 15760 Albion (aka 1992 QB1 and gave rise to term 'Cubewano') * 136472 Makemake, the largest known cubewano and a dwarf planet * 50000 Quaoar an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kuiper Belt
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia, and water. The Kuiper belt is home to most of the objects that astronomers generally accept as dwarf planets: Orcus, Pluto, Haumea, Quaoar, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region. The Kuiper belt was named after Dutch astronomer Gerard Kuiper, although he did not predict its existence. In 1992, minor planet (15760) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times the mass of Earth, and slightly more massive than its near-twin Uranus. Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere. It is referred to as one of the solar system's two ice giant planets (the other one being Uranus). Being composed primarily of gases and liquids, it has no well-defined "solid surface". The planet orbits the Sun once every 164.8 years at an average distance of . It is named after the Roman god of the sea and has the astronomical symbol , representing Neptune's trident. Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation. Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(385185) 1993 RO
(385185) 1993 RO is a plutino. It was the first plutino discovered after Pluto itself, with 1993 RP and (15788) 1993 SB a day and two days later, respectively. The discovery was made in 1993 at the Mauna Kea Observatory with a 2.2-meter telescope. Very little is known about (385185) 1993 RO. Even the diameter estimate of ~90 km is based on the assumed albedo of 0.09. KBO's found in 1993 include: (15788) 1993 SB, (15789) 1993 SC, (181708) 1993 FW, and (385185) 1993 RO. See also *List of trans-Neptunian objects This is a list of trans-Neptunian objects (TNOs), which are minor planets in the Solar System that orbit the Sun at a greater distance on average than Neptune, that is, their orbit has a semi-major axis greater than 30.1 astronomical units (AU) ... * Kuiper belt References External links IAUC 5865: 1993 RO* 385185 Discoveries by David C. Jewitt Discoveries by Jane Luu 19930914 {{centaurTNO-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
90482 Orcus
Orcus (minor-planet designation 90482 Orcus, provisional designation ) is a trans-Neptunian object, trans-Neptunian dwarf planet with a large moon, Vanth (moon), Vanth. It has a diameter of . The surface of Orcus is relatively bright with albedo reaching 23 percent, neutral in color and rich in water ice. The ice is predominantly in crystalline form, which may be related to past cryovolcanic activity. Other compounds like methane or ammonia may also be present on its surface. Orcus was discovered by American astronomers Michael E. Brown, Michael Brown, Chad Trujillo, and David L. Rabinowitz, David Rabinowitz on 17 February 2004. Orcus is a plutino, a trans-Neptunian object that is locked in a 2:3 resonance with the ice giant Neptune, making two revolutions around the Sun to every three of Neptune's. This is much like Pluto, except that the Phase (waves)#Phase difference, phase of Orcus's orbit is opposite to Pluto's: Orcus is at aphelion (most recently in 2019) around when Pluto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
15810 Arawn
15810 Arawn, provisional designation , is a trans-Neptunian object (TNO) from the inner regions of the Kuiper belt, approximately in diameter. It belongs to the plutinos, the largest class of resonant TNOs. It was named after Arawn, the ruler of the Celtic underworld, and discovered on 12 May 1994, by astronomers Michael J. Irwin, Michael Irwin and Anna N. Żytkow, Anna Żytkow with the 2.5-metre Isaac Newton Telescope at Roque de los Muchachos Observatory in the Canary Islands, Spain. Arawn is unique in that it has been observed at a much closer distance than most Kuiper belt objects, by the ''New Horizons'' spacecraft, which imaged it from a distance of in April 2016; this and its other observations have allowed its rotation period to be determined. Orbit and physical properties Arawn is moving in a relatively eccentric orbit entirely beyond the orbit of Neptune. With a semi-major axis of 39.4 Astronomical unit, AU, it orbits the Sun once every 247 years and 6 months ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hill Sphere
The Hill sphere of an astronomical body is the region in which it dominates the attraction of satellites. To be retained by a planet, a moon must have an orbit that lies within the planet's Hill sphere. That moon would, in turn, have a Hill sphere of its own. Any object within that distance would tend to become a satellite of the moon, rather than of the planet itself. One simple view of the extent of the Solar System is the Hill sphere of the Sun with respect to local stars and the galactic nucleus. In more precise terms, the Hill sphere approximates the gravitational sphere of influence of a smaller body in the face of perturbations from a more massive body. It was defined by the American astronomer George William Hill, based on the work of the French astronomer Édouard Roche. In the example to the right, the Earth's Hill sphere extends between the Lagrange points and , which lie along the line of centers of the two bodies. The region of influence of the smaller body i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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