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V-type Asteroids
A V-type asteroid or Vestoid is an asteroid whose spectral type is that of 4 Vesta. Approximately 6% of main-belt asteroids are vestoids, with Vesta being by far the largest of them. They are relatively bright, and rather similar to the more common S-type asteroid, which are also made up of stony irons and ordinary chondrites, with V-types containing more pyroxene than S-types. A large proportion of vestoids have orbital elements similar to those of Vesta, either close enough to be part of the Vesta family, or having similar eccentricities and inclinations but with a semi-major axis lying between about 2.18 AU and the 3:1 Kirkwood gap at 2.50 AU. This suggests that they originated as fragments of Vesta's crust. There seem to be two populations of Vestoids, one created 2 billion years ago and the other 1 billion years ago, coming respectively from the enormous southern-hemisphere craters Veneneia and Rheasilvia. Fragments that ended up in the 3:1 Jupiter resonance were perturbed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. Of the roughly one million known asteroids the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 AU from the Sun, in the main asteroid belt. Asteroids are generally classified to be of three types: C-type, M-type, and S-type. These were named after and are generally identified with carbonaceous, metallic, and silicaceous compositions, respectively. The size of asteroids varies greatly; the largest, Ceres, is almost across and qualifies as a dwarf planet. The total mass of all the asteroids combined is only 3% that of Earth's Moon. The majority of main belt asteroids follow slightly elliptical, stable orbits, revolving in the same direction as the Earth and taking from three to six years to comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheasilvia
Rheasilvia is the most prominent surface feature on the asteroid Vesta and is thought to be an impact crater. It is in diameter, which is 90% the diameter of Vesta itself, and is 95% the mean diameter of Vesta, . However, the mean is affected by the crater itself. It is 89% the mean equatorial diameter of , making it one of the largest craters in the Solar System, and at 75°S latitude, covers most of the southern hemisphere. The peak in the center of the crater is in diameter, and rises from its base, making it one of the tallest mountains known in the Solar System. Discovery Rheasilvia was discovered in Hubble Space Telescope images in 1997, but was not named until the arrival of the ''Dawn'' spacecraft in 2011. It is named after Rhea Silvia, a mythological vestal virgin and mother of the founders of Rome, Romulus and Remus.(NASA coordinates) Characteristics The crater partially obscures an earlier crater, named Veneneia, that at is almost as large. Rheasilvia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1459 Magnya
1459 Magnya, provisional designation , is a basaltic, slightly elongated asteroid from the outer regions of the asteroid belt, approximately 20 kilometers in diameter. Discovered by Grigory Neujmin at the Simeiz Observatory in 1937, this background asteroid was later named from the Latin word "Magnya", which means "clear, bright, wonderful" when literally translated into Russian. It is the only known basalt asteroid orbiting beyond 4 Vesta. Discovery ''Magnya'' was discovered on 4 November 1937, by Soviet astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula. Two nights later, it was independently discovered by French astronomer André Patry at Nice Observatory on 6 November 1937. The Minor Planet Center only recognizes the first discoverer, although Patry was first to announce the discovery. However, André Patry later received the honor to name the asteroid ''(see below)''. Orbit and classification ''Magnya'' is a non-family asteroid of the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
956 Elisa
956 Elisa ('' prov. designation:'' ''or'' ) is a Flora asteroid from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 8 August 1921, by German astronomer Karl Reinmuth at the Heidelberg Observatory. The V-type asteroid has a rotation period of 16.5 hours. It was named after Elisa Reinmuth, mother of the discoverer. Orbit and classification When applying the synthetic hierarchical clustering method (HCM) by Nesvorný, ''Elisa'' is a member of the Flora family (), a giant asteroid family and the largest family of stony asteroids in the main-belt. However, according to another HCM-analysis by Milani and Knežević (AstDys), it is a background asteroid as this analysis does not recognize the Flora asteroid clan. ''Elisa'' orbits the Sun in the inner asteroid belt at a distance of 1.8–2.8 AU once every 3 years and 6 months (1,273 days; semi-major axis of 2.3 AU). Its orbit has an eccentricity of 0.20 and an inclination of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Family
The Flora family (''adj. Florian''; ; also known as ''Ariadne family'') is a prominent family of stony asteroids located in the inner region of the asteroid belt. It is one of the largest families with more than 13,000 known members, or approximately 3.5% of all main-belt asteroids. The origin and properties of this family are relatively poorly understood. It is a very broad family which gradually fades into the surrounding background population. While the largest members, 8 Flora and 43 Ariadne, are located near the edge, there are several distinct groupings within the family, possibly created by later, secondary collisions. Due to this complex internal structure and the poorly defined boundaries, the Flora family has also been described as an asteroid clan. Only few interlopers have been identified. This family may be the source of the impactor that formed the Chicxulub crater, the likely culprit in the extinction of the dinosaurs. Characteristics The larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
809 Lundia
809 Lundia is a small, binary, V-type asteroid orbiting within the Flora family in the main belt. It is named after Lund Observatory, Sweden. Characteristics Lundia orbits within the Flora family. However, its V-type spectrum indicates that it is not genetically related to the Flora family, but rather is probably a fragment (two fragments, if its moon is included) ejected from the surface of 4 Vesta by a large impact in the past. Its orbit lies too far from Vesta for it to actually be a member of the Vesta family. It is not clear how it arrived at an orbit so far from Vesta, but other examples of V-type asteroids orbiting fairly far from their parent body are known. A mechanism of interplay between the Yarkovsky effect and nonlinear secular resonances (primarily involving Jupiter and Saturn) has been proposed. Binary system Lightcurve observations in 2005 revealed that Lundia is a binary system of two similarly sized objects orbiting their common centre of gravity. "Lundia" now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3908 Nyx
3908 Nyx is an Amor and Mars-crosser asteroid. It was discovered by Hans-Emil Schuster on August 6, 1980, and is named after Nyx, the Greek goddess of the night, after which Pluto's moon Nix is also named. It is 1–2 km in diameter and is a V-type asteroid, meaning that it may be a fragment of the asteroid 4 Vesta. Observations In 2000, radar observations conducted at the Arecibo and Goldstone observatories produced a model of Nyx's shape; the asteroid can best be described as spherical but with many protruding lumps. Name To avoid confusion with 3908 Nyx, Pluto's moon Nix was changed from the initial proposal of the classical spelling Nyx, to Nix. See also * 3551 Verenia * 4 Vesta * 4055 Magellan * HED meteorite * V-type asteroid A V-type asteroid or Vestoid is an asteroid whose spectral type is that of 4 Vesta. Approximately 6% of main-belt asteroids are vestoids, with Vesta being by far the largest of them. They are relatively bright, and rather similar to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near-Earth Objects
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). If a NEO's orbit crosses the Earth's orbit, and the object is larger than across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but a small fraction are comets. There are over 30,503 known near-Earth asteroids (NEAs) and over a hundred known short-period near-Earth comets (NECs). A number of solar-orbiting meteoroids were large enough to be tracked in space before striking the Earth. It is now widely accepted that collisions in the past have had a significant role in shaping the geological and biological history of the Earth. Asteroids as small as in diameter can cause significant damage to the local environment and human populations. Larger asteroids penetrate the atmosphere to the sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
9969 Braille
9969 Braille, provisional designation , is an eccentric, rare-type and elongated asteroid from the innermost regions of the asteroid belt, classified as Mars-crosser and slow rotator, approximately 1–2 kilometers in diameter. It was discovered in 1992, by astronomers at Palomar Observatory and later named after Louis Braille, the inventor of the writing system for the blind. It was photographed in closeup by the spacecraft Deep Space 1 in 1999, but a malfunction resulted in indistinct images. Discovery and naming Discovered on May 27, 1992, by E. F. Helin and K. J. Lawrence working at the Palomar observatory as part of NASA's Planet-Crossing Asteroid Survey, it was given the provisional designation . Later, it was named Braille in honour of Louis Braille as suggested by Kennedy Space Center software engineer Kerry Babcock in The Planetary Society's contest titled "Name That Asteroid". The official naming citation was published by the Minor Planet Center on 28 July 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars-crosser Asteroid
A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers Minor planet designation, numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and . Many databases, for instance the JPL Small-Body Database (JPL SBDB), only list asteroids with a perihelion greater than 1.3 Astronomical Unit, AU as Mars-crossers. An asteroid with a perihelion less than this is classed as a near-Earth object even though it is crossing the orbit of Mars as well as crossing (or coming near to) that of Earth. Nevertheless, these objects are listed on this page. A grazer is an object with a perihelion below the aphelion of Mars (1.67 AU) but above the Martian perihelion (1.38 AU). The JPL SBDB lists 13,500 Mars-crossing asteroids. Only 18 MCAs are brighter than Absolute magnitude#Solar System bodies (H), absolute magnitude (H) 12.5, which typically makes these asteroids with H<12.5 more than 13 km in d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diogenite
Diogenites are a group of the HED meteorite clan, a type of achondritic stony meteorites. Origin and composition Diogenites are currently believed to originate from deep within the crust of the asteroid 4 Vesta, and as such are part of the HED meteorite clan. There are about 40 distinct members known. Diogenites are composed of igneous rocks of plutonic origin, having solidified slowly enough deep within Vesta's crust to form crystals which are larger than in the eucrites. These crystals are primarily magnesium-rich orthopyroxene, with small amounts of plagioclase and olivine. Name Diogenites are named for Diogenes of Apollonia, an ancient Greek philosopher who was the first to suggest an outer space origin for meteorites. See also * Glossary of meteoritics * Vesta family The Vesta family (adj. ''Vestian''; ) is a family of asteroids. The cratering family is located in the inner asteroid belt in the vicinity of its namesake and principal body, 4 Vesta. It is one of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J-type Asteroids
J-type asteroids are asteroids with spectra similar to that of diogenite meteorites and so, presumably, to the deeper layers of the crust of 4 Vesta. Their spectra are rather similar to that of the V-type asteroids but have a particularly strong 1 μm absorption band. Examples are 2442 Corbett, 3869 Norton, 4005 Dyagilev, and 4215 Kamo.R. P. Binzel and S. Xu ''Chips off of asteroid 4 Vesta: Evidence for the parent body of basaltic achondrite meteorites'', Science, Vol. 260, p. 186 (1993). See also *Asteroid spectral types An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated ... References Asteroid spectral classes {{Asteroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
