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D-type Asteroids (SMASS)
D-type asteroids have a very low albedo and a featureless reddish spectrum. It has been suggested that they have a composition of organic-rich silicates, carbon and anhydrous silicates, possibly with water ice in their interiors. D-type asteroids are found in the outer asteroid belt and beyond; examples are 152 Atala, and 944 Hidalgo as well as the majority of Jupiter trojans. It has been suggested that the Tagish Lake meteorite was a fragment from a D-type asteroid, and that the Martian moon Phobos is closely related. The Nice model suggests that D-type asteroids may have originated in the Kuiper belt. 46 D-type asteroids are known, including: 3552 Don Quixote, 944 Hidalgo, 624 Hektor, and 10199 Chariklo. Examples A list of some of the largest D-type asteroids. See also * Asteroid spectral types * Tagish Lake (meteorite) The Tagish Lake meteorite fell at 16:43 UTC on 18 January 2000 in the Tagish Lake area in northwestern British Columbia, Canada. History Fragmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albedo
Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that reflects all incident radiation. Surface albedo is defined as the ratio of radiosity ''J''e to the irradiance ''E''e (flux per unit area) received by a surface. The proportion reflected is not only determined by properties of the surface itself, but also by the spectral and angular distribution of solar radiation reaching the Earth's surface. These factors vary with atmospheric composition, geographic location, and time (see position of the Sun). While bi-hemispherical reflectance is calculated for a single angle of incidence (i.e., for a given position of the Sun), albedo is the directional integration of reflectance over all solar angles in a given period. The temporal resolution may range from seconds (as obtained from flux measurements) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMASS Classification
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, the surface and internal compositions are presumably similar, while large bodies such as Ceres and Vesta are known to have internal structure. Over the years, there has been a number of surveys that resulted in a set of different taxonomic systems such as the Tholen, SMASS and Bus–DeMeo classifications. Taxonomic systems In 1975, astronomers Clark R. Chapman, David Morrison, and Ben Zellner developed a simple taxonomic system for asteroids based on color, albedo, and spectral shape. The three categories were labelled " C" for dark carbonaceous objects, " S" for stony (silicaceous) objects, and "U" for those that did not fit into either C or S. This basic division of asteroid spectra has since been expanded and clarified.Thomas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
884 Priamus
884 Priamus is a large Jupiter trojan from the Trojan camp, approximately in diameter. It was discovered on 22 September 1917, by German astronomer Max Wolf at Heidelberg Observatory in southern Germany. The dark D-type asteroid is one of the 20 largest Jupiter trojans and has a rotation period of 6.9 hours. It was named after the Trojan king Priam from Greek mythology. Orbit and classification ''Priamus'' is orbiting in the trailing Trojan camp, at Jupiter's Lagrangian point, 60 ° behind its orbit in a 1:1 resonance . It is also a non-family asteroid of the Jovian background population. It orbits the Sun at a distance of 4.5–5.8 AU once every 11 years and 10 months (4,308 days; semi-major axis of 5.18 AU). Its orbit has an eccentricity of 0.12 and an inclination of 9 ° with respect to the ecliptic. The body's observation arc begins at Heidelberg in November 1917, two months after its official discovery observation. Naming This minor planet was na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
773 Irmintraud
773 Irmintraud, provisional designation 1913 TV, is a dark and reddish, rare-type asteroid from the outer region of the asteroid belt, about 92 kilometers in diameter. It was discovered on 22 December 1913, by German astronomer Franz Kaiser at Heidelberg Observatory in southern Germany. The asteroid is classified as a D-type and T-type body in the Tholen and SMASS taxonomy, respectively. The rare spectral T-type is similar to D-types which are often found among Jupiter trojans thought to have originated from the Kuiper belt. It orbits the Sun at a distance of 2.6–3.1 AU once every 4 years and 10 months (1,763 days). Its orbit is tilted by 17 degrees to the plane of the ecliptic and shows a low eccentricity of 0.08. According to the surveys carried out by the Infrared Astronomical Satellite, IRAS, the Japanese Akari satellite, and the Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the minor planet's low albedo lies in the range of 0.04–0.05 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
721 Tabora
721 Tabora is a minor planet orbiting the Sun. Tabora was named at a conference in Hamburg, Germany in 1913. The name was chosen because the conference was held aboard the passenger cargo liner of the Deutsche Ost-Afrika Linie. The asteroid is orbiting at a distance of from the Sun with a period of and an eccentricity (ovalness) of 0.12. The orbital plane for is inclined at an angle of 8.3° to the plane of the ecliptic It is a member of the Cybele group in the outer belt, located close to the 7:4 and 16:9 orbital resonances with Jupiter. Photometric observations of this asteroid made during 2005 were used to produce a light curve showing a rotation period of with a brightness variation of 0.28 in magnitude. This is a low albedo D-type asteroid showing the characteristic featureless, reddish spectrum of that taxonomic class. It spans a girth of approximately 76 km. References External links * * Cybele asteroids 19111018 D-type asteroids (Tholen) Tabor ... [...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 librates around one of Jupiter's stable 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 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 the asteroid belt. Like main-belt asteroids, Jupiter trojans form families. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
368 Haidea
Haidea ( minor planet designation: 368 Haidea) is a large asteroid residing in the asteroid belt. It was discovered by Auguste Charlois on 19 May 1893 in Nice Nice ( , ; Niçard dialect, Niçard: , classical norm, or , nonstandard, ; it, Nizza ; lij, Nissa; grc, Νίκαια; la, Nicaea) is the prefecture of the Alpes-Maritimes departments of France, department in France. The Nice urban unit, agg .... References External links * * Background asteroids Haidea Haidea D-type asteroids (Tholen) 18930519 {{Beltasteroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
336 Lacadiera
Lacadiera ( minor planet designation: 336 Lacadiera) is a large Main belt asteroid. It is classified as a D-type asteroid and is probably composed of organic rich silicates, carbon and anhydrous silicates. The asteroid was discovered by Auguste Charlois on 19 September 1892 in Nice Nice ( , ; Niçard dialect, Niçard: , classical norm, or , nonstandard, ; it, Nizza ; lij, Nissa; grc, Νίκαια; la, Nicaea) is the prefecture of the Alpes-Maritimes departments of France, department in France. The Nice urban unit, agg .... In 2000, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.21 AU. The resulting data yielded an effective diameter of . References External links * * 000336 Discoveries by Auguste Charlois Named minor planets 000336 000336 18920919 {{Beltasteroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main-belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called asteroids or minor planets. This asteroid belt is also called the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System such as near-Earth asteroids and trojan asteroids. The asteroid belt is the smallest and innermost known circumstellar disc in the Solar System. About 60% of its mass is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea. The total mass of the asteroid belt is calculated to be 3% that of the Moon. Ceres, the only object in the asteroid belt large enough to be a dwarf planet, is about 950 km in diameter, whereas Vesta, Pallas, and Hygiea have mean diameters less than 600 km. The remaining bodies range down to the size of a dust particle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-type Asteroid
The X-group of asteroids collects together several types with similar spectra, but probably quite different compositions. Tholen classification In the Tholen classification the X-group consists of the following types: * E-type – with high albedo (> 0.30), composed of enstatite, forsterite and feldspar. They are found in the inner main-belt. * M-type – the largest grouping, intermediate albedo, "metallic", composed of iron and nickel, thought to be the progenitors of nickel–iron meteorites. They are found around 3.0 AU and in the Hungaria region (innermost main-belt). * P-type – low albedos (< 0.10) with featureless red spectra; presumably composed of carbonaceous chondrites, and found in the outer main-belt and in the Jupiter trojan region. Since in this scheme the albedo is crucial in discriminating between the above types, some objects for which albedo information was not available were assigned an X-type. An example of this is 50 Virginia. SMASS class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
279 Thule
Thule, minor planet designation: 279 Thule, is a large asteroid from the outer asteroid belt. It is classified as a D-type asteroid and is probably composed of organic-rich silicates, carbon and anhydrous silicates. Thule was the first asteroid discovered with a semi-major axis greater than 4 AU. It was discovered by Johann Palisa on 25 October 1888 in Vienna and was named after the ultimate northern land of Thule. Thule asteroids Thule was the first discovered member of the ''Thule dynamical group'', which as of 2008 is known to consist of three objects: 279 Thule, , and . The orbits of these bodies are unusual. They orbit in the outermost edge of the asteroid belt in a 4:3 orbital resonance with Jupiter, the result of the periodic force Jupiter exerts on a body with Thule's orbital period, in the same way (though with the reverse effect) as the Kirkwood gaps in the more inner parts of the asteroid belt. References External links * * Thule asteroids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main-belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called asteroids or minor planets. This asteroid belt is also called the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System such as near-Earth asteroids and trojan asteroids. The asteroid belt is the smallest and innermost known circumstellar disc in the Solar System. About 60% of its mass is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea. The total mass of the asteroid belt is calculated to be 3% that of the Moon. Ceres, the only object in the asteroid belt large enough to be a dwarf planet, is about 950 km in diameter, whereas Vesta, Pallas, and Hygiea have mean diameters less than 600 km. The remaining bodies range down to the size of a dust particle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
