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Minor Planets
According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor planet'', but that year's meeting IAU definition of planet, reclassified minor planets and comets into dwarf planets and Small Solar System body, small Solar System bodies (SSSBs).Press release, IAU 2006 General Assembly: Result of the IAU Resolution votes International Astronomical Union, August 24, 2006. Accessed May 5, 2008. In contrast to the eight official planets of the Solar System, all minor planets fail to clearing the neighborhood, clear their orbital neighborhood. Minor planets include asteroids (near- ... [...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 Trans-Neptunian object, 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 less massive than Eris (dwarf planet), Eris. Like other Kuiper belt objects, Pluto is made primarily of ice and rock and is much smaller than the inner planets. Pluto has roughly one-sixth the mass of the Moon and one-third its volume. Originally considered a planet, its classification was changed when astronomers adopted a new definition of planet, definition of ''planet''. Pluto has a moderately Orbital eccentricity, eccentric and Inclination, inclined orbit, ranging from from the Sun. Light from the Sun takes 5.5 hours to reach Pluto at its orbital distance of . Pluto's eccentric orbit periodically brings it closer to the Sun than Neptune, but a stabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravitationally bound Planetary system, system of the Sun and the objects that orbit it. It Formation and evolution of the Solar System, formed about 4.6 billion years ago when a dense region of a molecular cloud collapsed, forming the Sun and a protoplanetary disc. The Sun is a typical star that maintains a hydrostatic equilibrium, balanced equilibrium by the thermonuclear fusion, fusion of hydrogen into helium at its stellar core, core, releasing this energy from its outer photosphere. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trans-Neptunian Objects
A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has an orbital semi-major axis of 30.1 astronomical units (AU). Typically, TNOs are further divided into the Classical Kuiper belt object, classical and Resonant trans-Neptunian object, resonant objects of the Kuiper belt, the scattered disc and detached objects with the sednoids being the most distant ones. As of February 2025, the List of minor planets#Main index, catalog of minor planets contains List of trans-Neptunian objects, 1006 numbered and more than List of unnumbered trans-Neptunian objects, 4000 unnumbered TNOs. However, nearly 5900 objects with semimajor axis over 30 AU are present in the MPC catalog, with 1009 being numbered. The first trans-Neptunian object to be Planets beyond Neptune, discovered was Pluto in 1930. It took until 1992 to discover a second trans-Neptunian object orbiting t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaur (small Solar System Body)
In planetary astronomy, a centaur is a small Solar System body that orbits the Sun between Jupiter and Neptune and crosses the orbits of one or more of the giant planets. Centaurs generally have unstable orbits because of this; almost all their orbits have dynamic lifetimes of only a few million years, but there is one known centaur, 514107 Kaʻepaokaʻawela, which may be in a Retrograde and prograde motion, stable (though retrograde) orbit. Centaurs typically exhibit the characteristics of both asteroids and comets. They are named after the mythological centaurs that were a mixture of horse and human. Observational bias toward large objects makes determination of the total centaur population difficult. Estimates for the number of centaurs in the Solar System more than 1 km in diameter range from as low as 44,000 to more than 10,000,000. The first centaur to be discovered, under the definition of the Jet Propulsion Laboratory and the one used here, was 944 Hidalgo in 1920 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptune Trojan
Neptune trojans are bodies that orbit the Sun near one of the stable Lagrangian points of Neptune, similar to the trojans of other planets. They therefore have approximately the same orbital period as Neptune and follow roughly the same orbital path. Thirty-one Neptune trojans are currently known, of which 27 orbit near the Sun–Neptune Lagrangian point 60° ahead of Neptune and four orbit near Neptune's region 60° behind Neptune. The Neptune trojans are termed 'trojans' by analogy with the Jupiter trojans. The discovery of in a high-inclination (>25°) orbit was significant, because it suggested a "thick" cloud of trojans ( Jupiter trojans have inclinations up to 40°), which is indicative of freeze-in capture instead of in situ or collisional formation. It is suspected that large (radius ≈ 100 km) Neptune trojans could outnumber Jupiter trojans by an order of magnitude. E. I. Chiang and Y. Lithwick ''Neptune Trojans as a Testbed for Planet Formation'', The Astr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranus Trojan
A Uranus trojan is an asteroid that shares an orbit with Uranus Uranus is the seventh planet from the Sun. It is a gaseous cyan-coloured ice giant. Most of the planet is made of water, ammonia, and methane in a Supercritical fluid, supercritical phase of matter, which astronomy calls "ice" or Volatile ( ... and the Sun. Predicted in simulations earlier, two trojans have been discovered in Uranus’s Lagrangian point (leading Uranus). was the first body to be classified as such a trojan in 2013, while in 2017 became the second. Several theories have come to be on how such trojans could orbit Uranus. Gravitational scattering is the most popular, stating that such asteroids (or comets) could have been gravitationally pulled by the other planets, leading them on a perfect trajectory towards Uranus, or somewhere where Uranus’s gravitational pull is neutral. References Sources * * Trojans (astronomy) {{asteroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distant Minor Planet
A distant minor planet, or ''distant object'', is any minor planet found beyond Jupiter in the outer Solar System that is not commonly thought of as an "asteroid". The umbrella term is used by IAU's Minor Planet Center (MPC), which is responsible for the identification, designation and orbit computation of these objects. , the MPC maintains 6101 distant objects in its data base. Most distant minor planets are trans-Neptunian objects and centaurs, while relatively few are damocloids, Neptune trojans or Uranus trojans. All distant objects have a semi-major axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longe ... (average distance from the Sun) greater than 6 AU. This threshold, which is just beyond the orbit of Jupiter (5.2 AU), ensures that the vast majority of "true ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter Trojan
The Jupiter trojans, commonly called trojan asteroids or simply trojans, are a large group of asteroids that share the planet Jupiter's orbit around the Sun. Relative to Jupiter, each Trojan (celestial body), trojan Libration point orbit, librates around one of Jupiter's stable Lagrangian point, Lagrange points: either ', existing 60° ahead of the planet in its orbit, or ', 60° behind. Jupiter trojans are distributed in two elongated, curved regions around these Lagrangian points with an average semi-major axis of about 5.2 Astronomical unit, AU. The first Jupiter trojan discovered, 588 Achilles, was spotted in 1906 by German astronomer Max Wolf. More than 9,800 Jupiter trojans have been found . By convention, they are each named from Greek mythology after a figure of the Trojan War, hence the name "trojan". The total number of Jupiter trojans larger than 1 km in diameter is believed to be about , approximately equal to the number of asteroids larger than 1 km in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
