|
Yamato 791197
Yamato 791197, official abbreviation Y-791197, is a meteorite that was found in Antarctica on November 20, 1979. It is the first rock to be found on Earth identified as a lunar meteorite (see also ALH 81005). It was collected by National Institute of Polar Research, Japan. Classification and characteristics Weighing 52.4 grams, it is a weakly shocked feldspathic regolith breccia believed to have come from the lunar highlands on the far side of the Moon. It is classified as lunar-anorthositic breccia, a lunar meteorite that is primarily anorthositic. See also * Glossary of meteoritics * List of lunar meteorites This is a list of lunar meteorites. That is, meteorites that have been identified as having originated from Earth's Moon. Notes Where multiple meteorites are listed (e.g. NWA 4472/4485), they are believed to be pieces of the same original b ... References External links Chemical Classification {{Meteorites by name Meteorites found in Antarctica Lunar m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achondrite
An achondrite is a stony meteorite that does not contain chondrules. It consists of material similar to terrestrial basalts or plutonic rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies. As a result, achondrites have distinct textures and mineralogies indicative of igneous processes. Achondrites account for about 8% of meteorites overall, and the majority (about two-thirds) of them are HED meteorites, possibly originating from the crust of asteroid 4 Vesta. Other types include Martian, Lunar, and several types thought to originate from as-yet unidentified asteroids. These groups have been determined on the basis of e.g. the Fe/ Mn chemical ratio and the 17O/18O oxygen isotope ratios, thought to be characteristic "fingerprints" for each parent body. Classification Achondrites are classified into the following groups:O. Richard Norton. The Cambridge encyclopedia of meteorites. U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feldspathic
Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldspars and the ''alkali'' (potassium-sodium) feldspars. Feldspars make up about 60% of the Earth's crust, and 41% of the Earth's continental crust by weight. Feldspars crystalize from magma as both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar is known as anorthosite. Feldspars are also found in many types of sedimentary rocks. Compositions The feldspar group of minerals consists of tectosilicates, silicate minerals in which silicon ions are linked by shared oxygen ions to form a three-dimensional network. Compositions of major elements in common feldspars can be expressed in terms of three endmembers: * potassium feldspar (K-spar) en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Lunar Meteorites
This is a list of lunar meteorites. That is, meteorites that have been identified as having originated from Earth's Moon. Notes Where multiple meteorites are listed (e.g. NWA 4472/4485), they are believed to be pieces of the same original body. The mass shown is the total. *AaU - *ALH – Allan Hills, Antarctica *Asuka – Antarctica *Calcalong Creek – Australia *Dar al Gani – Libya *Dho - Dhofar, Oman *EET – Elephant Moraine, Antarctica *Kalahari – Botswana *LAP – LaPaz Icefield, Antarctica *MAC – MacAlpine Hills, Antarctica *MET – Meteorite Hills, Antarctica *MIL – Miller Range, Antarctica *NEA – Northeast Africa: Sudan *NWA – Northwest Africa: Morocco, Algeria *PCA – Pecora Escarpment, Antarctica *QUE – Queen Alexandra Range, Antarctica *SaU – Sayh al Uhaymir, Oman *Yamato – Antarctica Source: Washington University in St. Louis, Department of Earth and Planetary Science. See also * Glossary of meteoritics * List of Martian meteorites T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossary Of Meteoritics
This is a glossary of terms used in meteoritics, the science of meteorites. # * 2 Pallas – an asteroid from the asteroid belt and one of the likely parent bodies of the CR meteorites. * 4 Vesta – second-largest asteroid in the asteroid belt and likely source of the HED meteorites. * 221 Eos – an asteroid from the asteroid belt and one of the likely parent bodies of the CO meteorites. * 289 Nenetta – an asteroid from the asteroid belt and one of the likely parent bodies of the angrites. * 3103 Eger – an asteroid from the asteroid belt and one of the likely parent bodies of the aubrites. * 3819 Robinson – an asteroid from the asteroid belt and one of the likely parent bodies of the angrites. * IA meteorite – an iron meteorite group now part of the IAB group/complex. * IAB meteorite – an iron meteorite and primitive achondrite of the IAB group/complex. * IB meteorite – an iron meteorite group now part of the IAB group/complex. * IC meteorite – an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anorthositic
Anorthosite () is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. Anorthosites are of enormous geologic interest, because it is still not fully understood how they form. Most models involve separating plagioclase crystals based on their density. Plagioclase crystals are usually less dense than magma; so, as plagioclase crystallizes in a magma chamber, the plagioclase crystals float to the top, concentrating there. Anorthosite on Earth can be divided into five types: # Archean-age anorthosites # Proterozoic anorthosite (also known as massif or massif-type anorthosite) – the most abundant type of anorthosite on Earth # Layers within Layered Intrusions (e.g., Bushveld and Stillwater intrusions) # Mid-ocean ridge and transform fault anorthosites # Anorthosite xenoliths in other rocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Far Side Of The Moon
The far side of the Moon is the lunar hemisphere that always faces away from Earth, opposite to the Near side of the Moon, near side, because of synchronous rotation in the Moon's orbit. Compared to the near side, the far side's terrain is rugged, with a multitude of impact craters and relatively few flat and dark lunar mare, lunar maria ("seas"), giving it an appearance closer to other barren places in the Solar System such as Mercury (planet), Mercury and Callisto (moon), Callisto. It has one of the largest craters in the Solar System, the South Pole–Aitken basin. The hemisphere is sometimes called the "dark side of the Moon", where "dark" means "unknown" instead of "lacking sunlight" each side of the Moon experiences two weeks of sunlight while the opposite side experiences two weeks of night. About 18 percent of the far side is occasionally visible from Earth due to libration. The remaining 82 percent remained unobserved until 1959, when it was photographed by the Sovie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Highlands
The geology of the Moon (sometimes called selenology, although the latter term can refer more generally to "lunar science") is quite different from that of Earth. The Moon lacks a true Celestial body atmosphere, atmosphere, which eliminates erosion due to weather. It does not have any known form of plate tectonics, it has a lower gravity, and because of its small size, it cooled faster. The complex geomorphology of the lunar surface has been formed by a combination of processes, especially impact cratering and volcanism. The Moon is a planetary differentiation, differentiated body, with a crust (geology), crust, mantle (geology), mantle, and planetary core, core. Geology, Geological studies of the Moon are based on a combination of Earth-based telescope observations, measurements from Exploration of the Moon, orbiting spacecraft, moon rock, lunar samples, and geophysical data. Six locations were sampled directly during the crewed Apollo program landings from 1969 to 1972, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, tectonic breccia, igneous breccia, impact breccia, and hydrothermal breccia. A megabreccia is a breccia composed of very large rock fragments, sometimes kilometers across, which can be formed by landslides, impact events, or caldera collapse. Types Breccia is composed of coarse rock fragments held together by cement or a fine-grained matrix. Like conglomerate, breccia contains at least 30 percent of gravel-sized particles (particles over 2mm in size), but it is distinguished from conglomerate because the rock fragments have sharp edges that have not been worn down. These indicate that the gravel was deposited very close to its source area, since otherwise th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regolith
Regolith () is a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rocks, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestrial planets and moons. Etymology The term ''regolith'' combines two Greek words: (), 'blanket', and (), 'rock'. The American geologist George P. Merrill first defined the term in 1897, writing: Earth Earth's regolith includes the following subdivisions and components: * soil or pedolith * alluvium and other transported cover, including that transported by aeolian, glacial, marine, and gravity flow processes. * "saprolith'", generally divided into the ** ''upper saprolite'': completely oxidised bedrock ** ''lower saprolite'': chemically reduced partially weathered rocks ** ''saprock'': fractured bedrock with weathering restricted to fracture margins * volcanic ash and lava flows that are interbedded with unconsolidated material * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Institute Of Polar Research (Japan)
is the Japanese research institute for Antarctica. This agency manages several research bases on Antarctica. Research centers The NIPR has several research centers on Antarctica topics. Among others there are meteorological, geological, glacier motion, life science, ice dynamics, etc. In 1969, the NIPR started collecting meteorites. Their meteorite collection contains almost 17,000 specimens of meteorites — one of the world's largest meteorite collections. The Antarctic meteorite research in the United States is guided by ANSMET. Antarctic stations * Asuka Station * Dome F * Mizuho Station * Showa Station Planetary science education The NIPR Antarctic Meteorite Research Center loans a set of 30 thin sections of various meteorite types for use in education. The Institute prepared 20 sets of this collection. They were used in several European countries as well, including Hungary, Romania, Denmark, and Belgium. The set includes lunar and Martian meteorites. Asteroid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Meteorite
A lunar meteorite is a meteorite that is known to have originated on the Moon. A meteorite hitting the Moon is normally classified as a transient lunar phenomenon. Discovery In January 1982, John Schutt, leading an expedition in Antarctica for the ANSMET program, found a meteorite that he recognized to be unusual. Shortly thereafter, the meteorite now called Allan Hills 81005 was sent to Washington, DC, where Smithsonian Institution geochemist Brian Mason recognized that the sample was unlike any other known meteorite and resembled some rocks brought back from the Moon by the Apollo program. Several years later, Japanese scientists recognized that they had also collected a lunar meteorite, Yamato 791197, during the 1979 field season in Antarctica. , 371 lunar meteorites have been discovered, perhaps representing more than 30 separate meteorite falls (i.e., many of the stones are "paired" fragments of the same meteoroid). The total mass is more than . All lunar meteorites ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALH 81005
Allan Hills A81005 or ALH A81005 (sometimes also named without the "A" in front of the number) was the first lunar meteorite found on Earth. It was found in 1982 in the Allan Hills at the end of the Transantarctic Mountains, during a meteorite gathering expedition (ANSMET). Discovery and naming ALH A81005 was found on 17 January 1982 by John Schutt and Ian Whillans. It is named after the Allan Hills, a mountain chain in Antarctica where many meteorites are gathered by expeditions. The large number of meteorites collected in Antarctica and the lack of geographic terms that could be used for names have led to the adaption of the "Antarctic rules" for meteorite naming. Every meteorite found in Antarctica receives the names of the collection area (Allan Hills) and a number. The number consists of the year the expedition started "81" and a three digit number that is given out consecutively (005). The "A" in front of the number stands for meteorites collected by ANSMET expeditions and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_Labrador.jpg "Click for more on -> Anorthositic")
