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Chondrules in the chondrite classification Grassland. A millimeter scale is shown. Chondrules in the Carbonaceous Chondrite NWA 13887. A chondrule (from Ancient Greek χόνδρος chondros, grain) is a round grain found in a chondrite. Chondrules form as molten or partially molten droplets in space before being accreted to their parent asteroids.
Chondrules, metal grains, and other components likely formed in the solar nebula. These accreted together to form parent asteroids. These accreted together to form parent asteroids. Some of these bodies subsequently melted, forming metallic cores and olivine -rich mantles ; others were aqueously altered. [ 35 ]
A chondrite / ˈ k ɒ n d r aɪ t / is a stony (non-metallic) meteorite that has not been modified by either melting or differentiation of the parent body. [a] [1] They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids.
Aqueous alteration promotes a composition of hydrous phyllosilicates, magnetite, and olivine crystals occurring in a black matrix, and a possible lack of chondrules. It is thought they have not been heated above 50 °C (122 °F), indicating that they condensed in the cooler outer portion of the solar nebula.
The number of nebulae was then greatly increased by the efforts of William Herschel and his sister, Caroline Herschel. Their Catalogue of One Thousand New Nebulae and Clusters of Stars [16] was published in 1786. A second catalog of a thousand was published in 1789, and the third and final catalog of 510 appeared in 1802.
There are many indicators why some achondrites are deemed primitive. Some contain relic chondrules (e.g. Acapulcoite, Lodranite) and some have oxygen isotope ratios that are similar to chondrites. There are similarities in trace element concentrations between primitive achondrites and chondrites.
The Sun; Sirius A with Sirius B, a white dwarf; the Crab Nebula, a remnant supernova; A black hole (artist concept); Vela Pulsar, a rotating neutron star; M80, a globular cluster, and the Pleiades, an open star cluster; The Whirlpool galaxy and Abell 2744, a galaxy cluster; Superclusters, galactic filaments and voids
The main petrologic characteristic of Type 1 chondrites, such as CIs, is the lack of recognizable chondrules, thus excepting the sample from Tagish Lake. Yet small chondrule fragments and calcium–aluminium-rich inclusions (CAIs) do occur, but are quite rare. [73]