S-type asteroids are asteroids with a spectral type that is indicative of a siliceous mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second-most common after the carbonaceous C-type.
C-typeasteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks and minerals. They have an average density of about 1.7 g/cm3.
M-type asteroids are a spectral class of asteroids which appear to contain higher concentrations of metal phases than other asteroid classes, and are widely thought to be the source of iron meteorites.
A chondrite is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids. Some such bodies that are captured in the planet's gravity well become the most common type of meteorite by arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7% and 86.2%.
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, 944 Hidalgo and most 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.
B-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group; the 'B' indicates these objects are spectrally blue. In the asteroid population, B-class objects can be found in the outer asteroid belt, and also dominate the high-inclination Pallas family which includes the third-largest asteroid 2 Pallas. They are thought to be primitive, volatile-rich remnants from the early Solar System. There are 65 known B-type asteroids in the SMASS classification, and 9 in the Tholen classification as of March 2015.
38 Leda is a large, dark main-belt asteroid that was discovered by French astronomer J. Chacornac on January 12, 1856, and named after Leda, the mother of Helen of Troy in Greek mythology. In the Tholen classification system, it is categorized as a carbonaceous C-type asteroid, while the Bus asteroid taxonomy system lists it as a Cgh asteroid. The spectra of the asteroid displays evidence of aqueous alteration.
211 Isolda is a very large, dark main-belt asteroid. It is classified as a C-type asteroid and is probably composed of primitive carbonaceous material. The spectra of the asteroid displays evidence of aqueous alteration.
304 Olga is a large Main belt asteroid. It is classified as a C-type asteroid and is probably composed of carbonaceous material.
Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 8 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites. The C chondrites represent only a small proportion (4.6%) of meteorite falls.
An asteroid spectral type is assigned to asteroids based on their reflectance 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.
The X-group of asteroids collects together several types with similar spectra, but probably quite different compositions.
488 Kreusa is a C-type asteroid orbiting the Sun in the asteroid belt, with the type indicating a surface with a low albedo and high carbonaceous content. The spectra of the asteroid displays evidence of aqueous alteration.
712 Boliviana is a C-type asteroid from the asteroid belt, with the type indicating the surface has a low albedo with high carbonaceous content. The spectra of the asteroid displays evidence of aqueous alteration. It is named after Simón Bolívar.
The ordinary chondrites are a class of stony chondritic meteorites. They are by far the most numerous group, comprising 87% of all finds. Hence, they have been dubbed "ordinary". The ordinary chondrites are thought to have originated from three parent asteroids, with the fragments making up the H chondrite, L chondrite and LL chondrite groups respectively.
The Tagish Lake meteorite fell at 16:43 UTC on 18 January 2000 in the Tagish Lake area in northwestern British Columbia, Canada.
CI chondrites, also called C1 chondrites or Ivuna-type carbonaceous chondrites, are a group of rare carbonaceous chondrite, a type of stony meteorite. They are named after the Ivuna meteorite, the type specimen. CI chondrites have been recovered in France, Canada, India, and Tanzania. Their overall chemical composition closely resembles the elemental composition of the Sun, more so than any other type of meteorite.
This is a glossary of terms used in meteoritics, the science of meteorites.
Asteroidal water is water or water precursor deposits such as hydroxide (OH−) that exist in asteroids. The "snow line" of the Solar System lies outside of the main asteroid belt, and the majority of water is expected in minor planets. Nevertheless, a significant amount of water is also found inside the snow line, including in near-earth objects (NEOs).
CM chondrites are a group of chondritic meteorites which resemble their type specimen, the Mighei meteorite. The CM is the most commonly recovered group of the 'carbonaceous chondrite' class of meteorites, though all are rarer in collections than ordinary chondrites.
