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Sikhote-Alin Meteorite
In southeastern Russia, an iron meteorite fell on the Sikhote-Alin mountains in 1947. Large iron meteorite falls have been witnessed, and fragments have been recovered, but never before in recorded history has a fall of this magnitude occurred. An estimated 23 tonnes of fragments survived the fiery passage through the atmosphere and reached the Earth. Impact At around 10:30 AM on 12 February 1947, eyewitnesses in the Sikhote-Alin Mountains, Primorye, Soviet Union, observed a large bolide brighter than the sun that came out of the north and descended at an angle of about 41 degrees. The bright flash and the loud sound of the fall were observed for around the point of impact not far from Luchegorsk and approximately northeast of Vladivostok. A smoke trail, estimated at long, remained in the sky for several hours. As the meteor, traveling at a speed of about , entered the atmosphere, it began to break apart, and the fragments fell together, some burying themselves deep. At ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Meteorite
Iron meteorites, also called siderites or ferrous meteorites, are a type of meteorite that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that usually consists of two mineral phases: kamacite and taenite. Most iron meteorites originate from cores of planetesimals, with the exception of the IIE iron meteorite group. The iron found in iron meteorites was one of the earliest sources of usable iron available to humans, due to the malleability and ductility of the meteoric iron, before the development of smelting that signaled the beginning of the Iron Age. Occurrence Although they are fairly rare compared to the stony meteorites, comprising only about 5.7% of witnessed falls, iron meteorites have historically been heavily over-represented in meteorite collections. This is due to several factors: * They are easily recognized as unusual, as opposed to stony meteorites. Modern-day searches for meteorites in deserts and Antarctica yield a much more repre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolide
A bolide is normally taken to mean an exceptionally bright meteor, but the term is subject to more than one definition, according to context. It may refer to any large Impact crater, crater-forming body, or to one that explodes in the atmosphere. It can be a synonym for a Meteoroid#Fireball, fireball, sometimes specific to those with an apparent magnitude of −4 or brighter. Definitions The word ''bolide'' (; from Italian language, Italian via Latin, ) may refer to somewhat different phenomena depending on the context in which the word appears, and readers may need to make inferences to determine which meaning is intended in a particular publication. An early usage occurs in ''Natural History (Pliny), Natural History'', where Pliny the Elder describes two types of prodigium, prodigies, "those which are called lampades and those which are called bolides". At least one of the prodigies described by Pliny (a "spark" that fell, grew to the "size of the moon", and "returned into the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yevgeny Krinov
Yevgeny Leonidovich Krinov () (3 March 1906 – 2 January 1984), D.G.S., was a Soviet Russian astronomer and geologist, born in Otyassy () village in the Morshansky District of the Tambov Governorate of the Russian Empire. Krinov was a renowned meteorite researcher; the mineral Krinovite, discovered in 1966, was named after him. Scientific work From 1926 through 1930 Yevgeny Krinov worked in the meteor division of the Mineralogy Museum of the Soviet Academy of Sciences. During this period he conducted research into the Tunguska event under the supervision of Leonid Kulik. Krinov took part in the longest expedition to the Tunguska site in the years 1929–1930 as an astronomer. The data that was gathered during this expedition became the basis for his 1949 monograph (in Russian) called '' The Tunguska Meteorite''. In 1975, Yevgeny Krinov ordered the burning of 1500 negatives from a 1938 expedition by Leonid Kulik to the Tunguska event as part of an effort to dispose of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Belt
The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids or minor planets. The identified objects are of many sizes, but much smaller than planets, and, on average, are about one million kilometers (or six hundred thousand miles) apart. This asteroid belt is also called the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System. The asteroid belt is the smallest and innermost circumstellar disc in the Solar System. Classes of Small Solar System body, small Solar System bodies in other regions are the near-Earth objects, the Centaur (minor planet), centaurs, the Kuiper belt objects, the scattered disc objects, the sednoids, and the Oort cloud objects. About 60% of the main belt mass is contained in the four largest asteroids: Ceres (dwarf planet), C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellipse
In mathematics, an ellipse is a plane curve surrounding two focus (geometry), focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special type of ellipse in which the two focal points are the same. The elongation of an ellipse is measured by its eccentricity (mathematics), eccentricity e, a number ranging from e = 0 (the Limiting case (mathematics), limiting case of a circle) to e = 1 (the limiting case of infinite elongation, no longer an ellipse but a parabola). An ellipse has a simple algebraic solution for its area, but for Perimeter of an ellipse, its perimeter (also known as circumference), Integral, integration is required to obtain an exact solution. The largest and smallest diameters of an ellipse, also known as its width and height, are typically denoted and . An ellipse has four extreme points: two ''Vertex (geometry), vertices'' at the endpoints of the major axis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit
In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. To a close approximation, planets and satellites follow elliptic orbits, with the center of mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion. For most situations, orbital motion is adequately approximated by Newtonian mechanics, which explains gravity as a force obeying an inverse-square law. However, Albert Einstein's general theory of relativity, which accounts for gravity as due to curvature of spacetime, with orbits following geodesics, provides a more accurate calculation and u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteoroid
A meteoroid ( ) is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than ''asteroids'', ranging in size from grains to objects up to wide. Objects smaller than meteoroids are classified as ''micrometeoroids'' or ''space dust''. Many are fragments from comets or asteroids, whereas others are impact event, collision impact space debris, debris ejected from bodies such as the Moon or Mars. The visible passage of a meteoroid, comet, or asteroid atmospheric entry, entering Earth's atmosphere is called a meteor, and 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. An estimated 25 million meteoroids, micrometeoroids and other space debris enter Earth's atmosphere each day, which results in an estimated 15,000 tonnes of that material entering the atmosphere each year. A ''meteorite'' is the remains of a meteoroid that has surv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russian Academy Of Sciences
The Russian Academy of Sciences (RAS; ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across the Russian Federation; and additional scientific and social units such as libraries, publishing units, and hospitals. Peter the Great established the academy (then the St. Petersburg Academy of Sciences) in 1724 with guidance from Gottfried Wilhelm Leibniz, Gottfried Leibniz. From its establishment, the academy benefitted from a slate of foreign scholars as professors; the academy then gained its first clear set of goals from the 1747 Charter. The academy functioned as a university and research center throughout the mid-18th century until the university was dissolved, leaving research as the main pillar of the institution. The rest of the 18th century continuing on through the 19th century consisted of many published academic works from Academy scholars and a few Academy name changes, ending as The Imperial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteor
A meteor, known colloquially as a shooting star, is a glowing streak of a small body (usually meteoroid) going through Earth's atmosphere, after being heated to incandescence by collisions with air molecules in the upper atmosphere, creating a streak of light via its rapid motion and sometimes also by shedding glowing material in its wake. Although a meteor may seem to be a few thousand feet from the Earth, meteors typically occur in the mesosphere at altitudes from . The root word ''meteor'' comes from the Ancient Greek, Greek ''meteōros'', meaning "high in the air". Millions of meteors occur in Earth's atmosphere daily. Most meteoroids that cause meteors are about the size of a grain of sand, i.e. they are usually millimeter-sized or smaller. Meteoroid sizes can be calculated from their mass and density which, in turn, can be estimated from the observed meteor trajectory in the upper atmosphere. Meteors may occur in meteor shower, showers, which arise when Earth passes throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dow Planetarium
The Dow Planetarium (later renamed the Montreal Planetarium) is a decommissioned public planetarium located at Chaboillez Square southeast of downtown Montreal, Quebec, Canada. It closed permanently in October 2011. A new facility, the Rio Tinto Alcan Planetarium, near Olympic Stadium in Montreal, opened in April 2013. History The planetarium was opened in advance of Expo 67 and inaugurated on April 1, 1966, by then-Montreal mayor Jean Drapeau. Its inaugural show, "New Skies for a New City", premiered on April 4, 1966. Work had commenced on the project more than three years before its launch, under the guidance of Dr. Pierre Gendron, a former professor of chemistry and founding dean of the Faculty of Science at the University of Ottawa, who was an avid amateur astronomer. As president of the board of directors of Dow Breweries, Gendron convinced Dow to create a world-class planetarium in Montreal as part of the Canadian Centennial celebrations. The architectural firm sele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soviet Union
The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet Union, it dissolved in 1991. During its existence, it was the list of countries and dependencies by area, largest country by area, extending across Time in Russia, eleven time zones and sharing Geography of the Soviet Union#Borders and neighbors, borders with twelve countries, and the List of countries and dependencies by population, third-most populous country. An overall successor to the Russian Empire, it was nominally organized as a federal union of Republics of the Soviet Union, national republics, the largest and most populous of which was the Russian SFSR. In practice, Government of the Soviet Union, its government and Economy of the Soviet Union, economy were Soviet-type economic planning, highly centralized. As a one-party state go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
