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Willamette Meteorite
The Willamette Meteorite, officially named WillametteMeteoritical Bulletin Database: Willamette. The Meteoritical Society. Retrieved on August 16, 2008. and originally known as ''Tomanowos'' by the Clackamas Chinook Native American tribe, is an iron-nickel meteorite found in the of . It is the largest |
American Museum Of Natural History
The American Museum of Natural History (AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. Located in Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 21 interconnected buildings housing 45 permanent exhibition halls, in addition to a planetarium and a library. The museum collections contain about 32 million specimens of plants, animals, fungi, fossils, minerals, rocks, meteorites, human remains, and human cultural artifacts, as well as specialized collections for frozen tissue and genomic and astrophysical data, of which only a small fraction can be displayed at any given time. The museum occupies more than . AMNH has a full-time scientific staff of 225, sponsors over 120 special field expeditions each year, and averages about five million visits annually. The AMNH is a private 501(c)(3) organization. The naturalist Albert S. Bickmore devised the idea for the American Museum of Natural History in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willamette Valley
The Willamette Valley ( ) is a valley in Oregon, in the Pacific Northwest region of the United States. The Willamette River flows the entire length of the valley and is surrounded by mountains on three sides: the Cascade Range to the east, the Oregon Coast Range to the west, and the Calapooya Mountains to the south. The valley is synonymous with the cultural and political heart of Oregon and is home to approximately 70 percent of its population including the five largest cities in the state: Portland, Eugene, Salem, Gresham, and Hillsboro. The valley's numerous waterways, particularly the Willamette River, are vital to the economy of Oregon, as they continuously deposit highly fertile alluvial soils across its broad, flat plain. A massively productive agricultural area, the valley was widely publicized in the 1820s as a "promised land of flowing milk and honey". Throughout the 19th century, it was the destination of choice for the oxen-drawn wagon trains of emigr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium
Iridium is a chemical element; it has the symbol Ir and atomic number 77. This very hard, brittle, silvery-white transition metal of the platinum group, is considered the second-densest naturally occurring metal (after osmium) with a density of as defined by experimental X-ray crystallography. 191Ir and 193Ir are the only two naturally occurring isotopes of iridium, as well as the only stable isotopes; the latter is the more abundant. It is one of the most corrosion-resistant metals, even at temperatures as high as . Iridium was discovered in 1803 in the acid-insoluble residues of platinum ores by the English chemist Smithson Tennant. The name ''iridium'', derived from the Greek word ''iris'' (rainbow), refers to the various colors of its compounds. Iridium is one of the rarest elements in Earth's crust, with an estimated annual production of only in 2023. The dominant uses of iridium are the metal itself and its alloys, as in high-performance spark plugs, crucibles for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Widmanstätten Pattern
Widmanstätten patterns (), also known as Thomson structures, are figures of long Phase (matter), phases of nickel–iron, found in the octahedrite shapes of iron meteorite crystals and some pallasites. Iron meteorites are very often formed from a single crystal of iron-nickel alloy, or sometimes a number of large crystals that may be many meters in size, and often lack any discernable crystal boundary on the surface. Large crystals are extremely rare in metals, and in meteors they occur from extremely slow cooling from a molten state in the vacuum of space when the Solar System first formed. Once in the solid state, the slow cooling then allows the solid solution to Precipitation (chemistry), precipitate a separate phase that grows within the crystal lattice, which form at very specific angles that are determined by the lattice. In meteors, these interstitial defects can grow large enough to fill the entire crystal with needle or ribbon-like structures easily visible to the ... [...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] |
Planetesimal
Planetesimals () are solid objects thought to exist in protoplanetary disks and debris disks. Believed to have formed in the Solar System about 4.6 billion years ago, they aid study of its formation. Formation A widely accepted theory of planet formation, the planetesimal hypothesis of Viktor Safronov, states that planets form from cosmic dust grains that collide and stick to form ever-larger bodies. Once a body reaches around a kilometer in size, its constituent grains can attract each other directly through mutual gravity, enormously aiding further growth into moon-sized protoplanets. Smaller bodies must instead rely on Brownian motion or turbulence to cause the collisions leading to sticking. The mechanics of collisions and mechanisms of sticking are intricate. Alternatively, planetesimals may form in a very dense layer of dust grains that undergoes a collective gravitational instability in the mid-plane of a protoplanetary disk—or via the concentration and gravitatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorus
Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared artificially, the two most common allotropes being white phosphorus and red phosphorus. With as its only stable isotope, phosphorus has an occurrence in Earth's crust of about 0.1%, generally as phosphate rock. A member of the pnictogen family, phosphorus readily forms a wide variety of organic compound, organic and inorganic compound, inorganic compounds, with as its main oxidation states +5, +3 and −3. The isolation of white phosphorus in 1669 by Hennig Brand marked the scientific community's first discovery since Antiquity of an element. The name phosphorus is a reference to the Phosphorus (morning star), god of the Morning star in Greek mythology, inspired by the faint glow of white phosphorus when exposed to oxygen. This property is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalt
Cobalt is a chemical element; it has Symbol (chemistry), symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, somewhat brittle, gray metal. Cobalt-based blue pigments (cobalt blue) have been used since antiquity for jewelry and paints, and to impart a distinctive blue tint to glass. The color was long thought to be due to the metal bismuth. Miners had long used the name ''kobold ore'' (German language, German for ''goblin ore'') for some of the blue pigment-producing minerals. They were so named because they were poor in known metals and gave off poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), which was ultimately named for the ''kobold''. Today, some cobalt is produced sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel
Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks, and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere. Meteoric nickel is found in combination with iron, a reflection of the origin of those elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's outer and inner cores. Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's outer and inner core. It is the fourth most abundant element in the Earth's crust, being mainly deposited by meteorites in its metallic state. Extracting usable metal from iron ores requires kilns or furnaces capable of reaching , about 500 °C (900 °F) higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BC and the use of iron tools and weapons began to displace copper alloys – in some regions, only around 1200 BC. That event is considered the transition from the Bronze Age to the Iron Age. In the modern world, iron alloys, such as steel, stainless steel, cast iron and special steels, are by far the most common industrial metals, due to their mechan ... [...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] |
