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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.
Fall – a meteorite that was seen while it fell to Earth and found. Find – a meteorite that was found without seeing it fall. Fossil meteorite – a meteorite that was buried under layers of sediment before the start of the Quaternary period. Some or all of the original cosmic material has been replaced by diagenetic minerals.
The 60-tonne, 2.7 m-long (8.9 ft) Hoba meteorite in Namibia is the largest known intact meteorite.[1]A meteorite is a rock that originated in outer space and has fallen to the surface of a planet or moon.
Octahedrites are the most common structural class of iron meteorites. The structures occur because the meteoric iron has a certain nickel concentration that leads to the exsolution of kamacite out of taenite while cooling.
Stony-iron meteorites or siderolites are meteorites that consist of nearly equal parts of meteoric iron and silicates. This distinguishes them from the stony meteorites, that are mostly silicates, and the iron meteorites, that are mostly meteoric iron. [1] Stony-iron meteorites are all differentiated, meaning that they show signs of alteration.
Pallasites are a rare type of meteorite. Only 61 are known to date, including 10 from Antarctica, with four being observed falls. [9] [10] The following four falls are in chronological order: Mineo, Sicily, Italy. A luminous meteor was observed and an object seen to fall with a loud roar in May 1826. Only 46 grams (1.6 oz) are preserved in ...
Iron meteorite groups are designated with a Roman numeral and one or two letters. Classification is based on diagrams in which the nickel content of meteoric iron is plotted against certain trace elements (e.g. gallium, germanium and iridium). Clusters in these diagrams are assigned a row (Roman numeral) and a letter in alphabetical order.
The L type ordinary chondrites are the second most common group of meteorites, accounting for approximately 35% of all those catalogued, and 40% of the ordinary chondrites. [1] 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 ...