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Meteoritics
Meteoritics is the science that deals with meteors, meteorites, and meteoroids. It is closely connected to cosmochemistry, mineralogy and geochemistry. A specialist who studies meteoritics is known as a ''meteoriticist''. Scientific research in meteoritics includes the collection, identification, and classification of meteorites and the analysis of samples taken from them in a laboratory. Typical analyses include investigation of the minerals that make up the meteorite, their relative locations, orientations, and chemical compositions; analysis of isotope ratios; and radiometric dating. These techniques are used to determine the age, formation process, and subsequent history of the material forming the meteorite. This provides information on the history of the Solar System, how it formed and evolved, and the process of planet formation. History of investigation Before the documentation of L'Aigle it was generally believed that meteorites were a type of superstition and those wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteor
A meteoroid () is a small rocky or metallic body in outer space. Meteoroids are defined as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than this are classified as micrometeoroids or space dust. Most are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars. When a meteoroid, comet, or asteroid enters Earth's atmosphere at a speed typically in excess of , aerodynamic heating of that object produces a streak of light, both from the glowing object and the trail of glowing particles that it leaves in its wake. This phenomenon is called a meteor or "shooting star". Meteors typically become visible when they are about 100 km above sea level. A series of many meteors appearing seconds or minutes apart and appearing to originate from the same fixed point in the sky is called a meteor shower. A meteorite is the remains of a meteoroid th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L'Aigle (meteorite)
L'Aigle is a L6 meteorite that fell on 26 April 1803 in Lower Normandy, France. History In the early afternoon of 26 April 1803 a meteorite shower of more than 3000 fragments fell upon the town of L'Aigle in Normandy, France. Upon hearing of this event the French Academy of Sciences sent the young scientist Jean-Baptiste Biot to investigate that spectacular fall of stones. After painstaking work in the field he reported two kinds of evidence pointing to an extraterrestrial origin for the stones: # ''Physical evidence'': the sudden appearance of many identical stones similar to other stones fallen from the sky in other places # ''Moral evidence'': many witnesses who observed a "''rain of stones thrown by the meteor''" Biot's passionate paper describing how these stones must undoubtedly be of extraterrestrial origin effectively gave birth to the science of meteoritics. The L'Aigle event was a milestone in the understanding of meteorites and their origins because at that time the me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Nebula
The formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small Solar System bodies formed. This model, known as the nebular hypothesis, was first developed in the 18th century by Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace. Its subsequent development has interwoven a variety of scientific disciplines including astronomy, chemistry, geology, physics, and planetary science. Since the dawn of the space age in the 1950s and the discovery of extrasolar planets in the 1990s, the model has been both challenged and refined to account for new observations. The Solar System has evolved considerably since its initial formation. Many moons have formed from circling discs of gas and dust around their parent planets, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay Mineral
Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay minerals form in the presence of water and have been important to life, and many theories of abiogenesis involve them. They are important constituents of soils, and have been useful to humans since ancient times in agriculture and manufacturing. Properties Clay is a very fine-grained geologic material that develops plasticity when wet, but becomes hard, brittle and non–plastic upon drying or firing. It is a very common material, and is the oldest known ceramic. Prehistoric humans discovered the useful properties of clay and used it for making pottery. The chemistry of clay, including its capacity to retain nutrient cations such as potassium and ammonium, is important to soil fertility. Because the individual particles in clay are less than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monahans Meteorite
Monahans can refer to: *Monahans, Texas *Monahans Sandhills State Park *Monahans-Wickett-Pyote Independent School District *The XScale PXA3xx chips, for which Monahans was a code-name See also *Monahan *Monaghan Monaghan ( ; ) is the county town of County Monaghan, Republic of Ireland, Ireland. It also provides the name of its Civil parishes in Ireland, civil parish and Monaghan (barony), barony. The population of the town as of the 2016 census was 7 ... {{dab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zag Meteorite
Zag or ZAG may refer to: Places *Zag, Kentucky, US *Zag, Mongolia, a district *Zag, Morocco, a town *Zagreb Airport, Croatia IATA airport code People *Zag de Sujurmenza, 13th-century Spanish astronomer *Zag, of English band Zag and the Coloured Beads Other uses *AZGP1 (Zinc-alpha-2-glycoprotein) *Zaghawa language, ISO 639-3 code *Zag numbers, a type of alternating permutation *Zag Industries, acquired by Stanley Black & Decker in 1990 *Gonzaga Bulldogs, known unofficially as the Zags *TrueCar TrueCar, Inc. is an automotive pricing and information website for new and used car buyers. The service allows users to see what others paid for any new or used vehicle in their local area and receive upfront prices from a network of over 15,000 ..., Inc., formerly Zag.com See also * Zig and Zag (other) * Zigzag (other) {{Disambiguation, geo, given name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroidal Water
Asteroidal water is water or water precursor deposits such as hydroxide (OH−) that exist in asteroids (i.e., small Solar System bodies (SSSBs) not explicitly in the subcategory of comets). The "snow line" of the Solar System lies outside of the main asteroid belt, and the majority of water is expected in minor planets (e.g. Kuiper belt objects (KBOs) and Centaurs). Nevertheless, a significant amount of water is also found inside the snow line, including in near-earth objects (NEOs). The formation of asteroidal water mirrors that of water formation in the Solar System, either from transfer via bombardment, migration, ejection, or other means. Asteroidal water has recently been pursued as a resource to support deep space exploration activities, for example, for use as a rocket propellant, human consumption, or for agricultural production, etc. History Meteorites Since the early 1800s, meteorites have been assumed to be "space rocks", not terrestrial or atmospheric phenomena. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wadsleyite
Wadsleyite is an orthorhombic mineral with the formula β-(Mg,Fe)2SiO4. It was first found in nature in the Peace River meteorite from Alberta, Canada. It is formed by a phase transformation from olivine (α-(Mg,Fe)2SiO4) under increasing pressure and eventually transforms into spinel-structured ringwoodite (γ-(Mg,Fe)2SiO4) as pressure increases further. The structure can take up a limited amount of other bivalent cations instead of magnesium, but contrary to the α and γ structures, a β structure with the sum formula Fe2SiO4 is not thermodynamically stable. Its cell parameters are approximately a = 5.7 Å, b = 11.71 Å and c = 8.24 Å. Wadsleyite is found to be stable in the upper part of the Transition Zone of the Earth's mantle between in depth. Because of oxygen atoms not bound to silicon in the Si2O7 groups of wadsleyite, it leaves some oxygen atoms insufficiently bonded. Thus, these oxygens are hydrated easily, allowing for high concentrations of hydroge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stishovite
Stishovite is an extremely hard, dense tetragonal form (Polymorphism (materials science), polymorph) of silicon dioxide. It is very rare on the Earth's surface; however, it may be a predominant form of silicon dioxide in the Earth, especially in the Lower mantle (Earth), lower mantle. Stishovite was named after Sergey M. Stishov, a Russian high-pressure physicist who first synthesized the mineral in 1961. It was discovered in Meteor Crater in 1962 by Edward C. T. Chao. Unlike other silica polymorphs, the crystal structure of stishovite resembles that of rutile (TiO2). The silicon in stishovite adopts an octahedral coordination geometry, being bound to six oxides. Similarly, the oxides are three-connected, unlike low-pressure forms of SiO2. In most silicates, silicon is tetrahedral, being bound to four oxides. It was long considered the hardest known oxide (~30 GPa Vickers); however, boron suboxide has been discovered in 2002 to be much harder. At normal temperature and pressur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ringwoodite
Ringwoodite is a high-pressure phase of Mg2SiO4 (magnesium silicate) formed at high temperatures and pressures of the Earth's mantle between depth. It may also contain iron and hydrogen. It is polymorphous with the olivine phase forsterite (a magnesium iron silicate). Ringwoodite is notable for being able to contain hydroxide ions (oxygen and hydrogen atoms bound together) within its structure. In this case two hydroxide ions usually take the place of a magnesium ion and two oxide ions. Combined with evidence of its occurrence deep in the Earth's mantle, this suggests that there is from one to three times the world ocean's equivalent of water in the mantle transition zone from 410 to 660 km deep. This mineral was first identified in the Tenham meteorite in 1969, and is inferred to be present in large quantities in the Earth's mantle. Ringwoodite was named after the Australian earth scientist Ted Ringwood (1930–1993), who studied polymorphic phase transitions in the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Majorite
Majorite is a type of garnet mineral found in the mantle of the Earth. Its chemical formula is Mg3(MgSi)(SiO4)3. It is distinguished from other garnets in having Si in octahedral as well as tetrahedral coordination. Majorite was first described in 1970 from the Coorara Meteorite of Western Australia and has been reported from various other meteorites in which majorite is thought to result from an extraterrestrial high pressure shock event. Mantle derived xenoliths containing majorite have been reported from potassic ultramafic magmas on Malaita Island on the Ontong Java Plateau Southwest Pacific. Synthetic magnesium endmember majorite Pure synthetic magnesium majorite (MgSiO3) is polymorphous with enstatite, and akimotoite. Majorite is a member of the garnet group. It has Mg in eight-coordination with oxygen; it also has both Mg and Si in octahedral (6) coordination; and Si in tetrahedral (4) coordination with oxygen. Unlike most garnets, which are cubic, pure MgSiO3 majorite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akimotoite
Akimotoite is a rare silicate mineral in the ilmenite group of minerals, with the chemical formula . It is polymorphous with pyroxene and with bridgmanite, a natural silicate perovskite that is the most abundant mineral in Earth's silicate mantle. Akimotoite has a vitreous luster, is colorless, and has a white or colorless streak. It crystallizes in the trigonal crystal system in space group R. It is the silicon analogue of geikielite (MgTiO3). Crystal structure The crystal structure is similar to that of ilmenite (FeTiO3) with Si and Mg in regular octahedral coordination with oxygen. The Si and Mg octahedra align in discrete layers alternating up the c-axis. The space group is R (trigonal) with a = 4.7284 Å; c = 13.5591 Å; V = 262.94 Å3; Z = 6.Horiuchi, H., Hirano, M., Ito, E., and Matsui, Y. (1982) MgSiO3 (ilmenite-type): single crystal X-ray diffraction study. American Mineralogist, 67, 788-793 Occurrence Akimotoite was found in the Tenham meteorites in Queen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
