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Österplana 065
Österplana 065 (Öst 65) is an Ordovician fossil meteorite found in the Thorsberg quarry in Sweden on June 26, 2011, and scientifically described in 2016. Measuring 8×6.5×2 cm, it impacted the Earth 470 million years ago, during the Ordovician According to the naming conventions of the Meteoritical Society, the meteorite was named after the locality at which it was found, Österplana. The meteorite type does not fit into existing meteorite classification. It was preliminarily classified as "winonaite-like". The level of chromium isotope 54Cr in Österplana 065 is similar to those in ordinary chondrites, while oxygen isotopes are similar to those in some rare primitive achondrites. Österplana 065 also features a chromium-spinel–rutile assemblage, not observed in other meteorites. Österplana 065 is believed to have originated from a larger asteroid, and belongs to a meteorite type that does not presently fall on the Earth. See also *Ordovician meteor event The Ordovici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium
Chromium is a chemical element; it has Symbol (chemistry), symbol Cr and atomic number 24. It is the first element in Group 6 element, group 6. It is a steely-grey, Luster (mineralogy), lustrous, hard, and brittle transition metal. Chromium is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating (electroplating with chromium) together comprise 85% of the commercial use. Chromium is also greatly valued as a metal that is able to be highly polishing, polished while resisting tarnishing. Polished chromium reflects almost 70% of the visible spectrum, and almost 90% of infrared, infrared light. The name of the element is derived from the Ancient Greek, Greek word χρῶμα, ''chrōma'', meaning color, because many chromium compounds are intensely colored. Indust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotopes Of Chromium
Naturally occurring chromium (24Cr) is composed of four stable isotopes; 50Cr, 52Cr, 53Cr, and 54Cr with 52Cr being the most abundant (83.789% natural abundance). 50Cr is suspected of decaying by β+β+ to 50Ti with a half-life of (more than) 1.8×1017 years. Twenty-two radioisotopes, all of which are entirely synthetic, have been characterized, the most stable being 51Cr with a half-life of 27.7 days. All of the remaining radioactive isotopes have half-lives that are less than 24 hours and the majority of these have half-lives that are less than 1 minute. This element also has two meta states, 45mCr, the more stable one, and 59mCr, the least stable isotope or isomer. 53Cr is the radiogenic decay product of 53 Mn. Chromium isotopic contents are typically combined with manganese isotopic contents and have found application in isotope geology. Mn-Cr isotope ratios reinforce the evidence from 26Al and 107 Pd for the early history of the Solar System. Variations in 53Cr/52Cr and Mn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Meteor Event
The Ordovician meteor event was a dramatic increase in the rate at which L chondrite meteorites fell to Earth during the Middle Ordovician period, about 467.5±0.28 million years ago, lasting for about 40 million years. This rate increase is indicated by abundant fossil L chondrite meteorites in a quarry in Sweden and enhanced concentrations of ordinary chondritic chromite grains in sedimentary rocks from this time. According to a 2019 study, this temporary increase in the impact rate could have been caused by the destruction of the L chondrite parent body that was in diameter and orbited in the asteroid belt between Mars and Jupiter. This occurred around 468 ± 0.3 million years ago having scattered fragments into Earth-crossing orbits, a chronology which is also supported by shock ages in numerous L chondrite meteorites that fall to Earth today. It has been speculated that this influx contributed to, or possibly even instigated, the Great Ordovician Biodiversification Even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). Asteroids are rocky, metallic, or icy bodies with no atmosphere, and are broadly classified into C-type asteroid, C-type (carbonaceous), M-type asteroid, M-type (metallic), or S-type asteroid, S-type (silicaceous). The size and shape of asteroids vary significantly, ranging from small rubble piles under a kilometer across to Ceres (dwarf planet), Ceres, a dwarf planet almost 1000 km in diameter. A body is classified as a comet, not an asteroid, if it shows a coma (tail) when warmed by solar radiation, although recent observations suggest a continuum between these types of bodies. Of the roughly one million known asteroids, the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 astronomical unit, AU ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium
Chromium is a chemical element; it has Symbol (chemistry), symbol Cr and atomic number 24. It is the first element in Group 6 element, group 6. It is a steely-grey, Luster (mineralogy), lustrous, hard, and brittle transition metal. Chromium is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating (electroplating with chromium) together comprise 85% of the commercial use. Chromium is also greatly valued as a metal that is able to be highly polishing, polished while resisting tarnishing. Polished chromium reflects almost 70% of the visible spectrum, and almost 90% of infrared, infrared light. The name of the element is derived from the Ancient Greek, Greek word χρῶμα, ''chrōma'', meaning color, because many chromium compounds are intensely colored. Indust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primitive Achondrite
Primitive achondrites are a subdivision of meteorites. They are classified on the same rank (historically called "Class") and lying between chondrites and achondrites. They are called primitive because they are achondrites that have retained much of their original chondritic properties. Very characteristic are relic chondrules and chemical compositions close to the composition of chondrites. These observations are explained as melt residues, partial melting, or extensive recrystallization. History The concept of primitive achondrites was first summarized in 1983. In 2006 a classification was published that assigned 7 groups to the primitive achondrites, but the classification remains controversial. The authors define primitive achondrites as meteorites "''that exceeded their solidus temperature on the parent body''" and thus would partially melt. Meteorites that have been fully melted are included if they did not reach isotopic equilibrium on their parent body. Description There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen Isotopes
There are three known stable isotopes of oxygen (8O): , , and . Radioactive isotopes ranging from to have also been characterized, all short-lived. The longest-lived radioisotope is with a half-life of , while the shortest-lived isotope is the unbound with a half-life of , though half-lives have not been measured for the unbound heavy isotopes and . List of isotopes , -id=Oxygen-11 , , style="text-align:right" , 8 , style="text-align:right" , 3 , , [] , proton emission, 2p , , (3/2−) , , , -id=Oxygen-12 , , style="text-align:right" , 8 , style="text-align:right" , 4 , , , 2p , , 0+ , , , - , rowspan=3, , rowspan=3 style="text-align:right" , 8 , rowspan=3 style="text-align:right" , 5 , rowspan=3, , rowspan=3, , β+ () , , rowspan=3, (3/2−) , rowspan=3, , rowspan=3, , - , β+p () , , - , β+p,α ( , - , Can be used in NMR studies of metabolic pathways. , style="text-align:right" , 8 , style="text-align:right" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordinary Chondrite
The ordinary chondrites (sometimes called the O 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. Origin It is suspected that they are not representative of typical asteroid parent bodies, but rather of a select few which are advantageously placed to send impact fragments to Earth-crossing orbits. Such positions are e.g. near Kirkwood gaps and/or secular resonances in the main asteroid belt. In fact, only the one rather insignificant asteroid 3628 Božněmcová has been identified to have a spectrum close to the ordinary chondrites. A probable parent body of the H chondrites (comprising about 46% of the ordinary chondrites) is 6 Hebe, but its spectrum is dissimilar due to what i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winonaite
Winonaites are a group of primitive achondrite meteorites. Like all primitive achondrites, winonaites share similarities with chondrites and achondrites. They show signs of metamorphism, partial melting, brecciation and relic chondrules. Their chemical and mineralogical composition lies between H and E chondrites. Naming and history The winonaite group is named after the type specimen, the Winona meteorite. The name itself derived from Winona, Arizona where the type specimen was said to be found during an archaeological excavation of the Sinagua village Elden Pueblo in September 1928. The Sinagua lived in the village between 1150 and 1275. The meteorite was said to be retrieved from the cist of one of the rooms. However, a later study indicates the meteorite was found at another Sinagua site and not in Elden Pueblo.A. L. Christenson "J. W. Simmons' account of the discovery of the Winona meteorite."''Meteorite'' 10(3):14–16, 2004. As of 2021, 54 meteorites are included in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinel
Spinel () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , a diminutive form of ''spine,'' in reference to its pointed crystals. Properties Spinel crystallizes in the isometric system; common crystal forms are octahedron, octahedra, usually Crystal twinning, twinned. It has no true Cleavage (crystal), cleavage, but shows an octahedral Parting (crystal), parting and a conchoidal fracture. Its Mohs scale of mineral hardness, hardness is 8, its specific gravity is 3.5–4.1, and it is transparent to opaque with a vitreous to dull Lustre (mineralogy), luster. It may be colorless, but is usually various shades of red, lavender (color), lavender, blue, green, brown, black, or yellow. Chromium(III) causes the red color in spinel from Burma. Some spinels are among the most famous gemstones; among them are the Black Prince's Ruby and the "Timur ruby" in the British Crown Jewels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features Peer review, peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2022 ''Journal Citation Reports'' (with an ascribed impact factor of 50.5), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in the autumn of 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander MacMillan (publisher), Alexander MacMillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorite Classification
In meteoritics, a meteorite classification system attempts to group similar meteorites and allows scientists to communicate with a standardized terminology when discussing them. Meteorites are classified according to a variety of characteristics, especially mineralogical, petrological, chemical, and isotopic properties. Terminology There is no single, standardized terminology used in meteorite classification; however, commonly used terms for categories include ''types'', ''classes'', ''clans'', ''groups'', and ''subgroups''. Some researchers hierarchize these terms, but there is no consensus as to which hierarchy is most appropriate. Meteorites that do not fit any known group (though they may fit somewhere within a higher level of classification) are ''ungrouped''. Genetic relationships Meteorite classification may indicate that a "genetic" relationship exists between similar meteorite specimens. Similarly classified meteorites may share a common origin, and therefore may co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
