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Encyclopedia > Tunguska event
Trees knocked over by the Tunguska blast. Photograph from Kulik's 1927 expedition
Trees knocked over by the Tunguska blast. Photograph from Kulik's 1927 expedition

The Tunguska Event, sometimes called the Tunguska explosion, was a massive explosion that occurred near the Podkamennaya (Lower Stony) Tunguska River in what is now Krasnoyarsk Krai of Russia, at around 7:14 a.m.[1] (0:14 UT, 7:02 a.m. local solar time[2]) on June 30, 1908 (June 17 in the Julian calendar, in use locally at the time).[2] Image File history File links Felled trees at Tunguska, 1927 04:13, 24 Jul 2004 CYD From English Wikipedia, en:Image:Tunguska01. ... Image File history File links Felled trees at Tunguska, 1927 04:13, 24 Jul 2004 CYD From English Wikipedia, en:Image:Tunguska01. ... Подкаменная Тунгуска Length 1,159 mi 1,865 km Elevation of the source  ? m Average discharge  ? m³/s Area watershed  ? km² Origin  ? Mouth Yenisei River Basin countries Russia The Stony Tunguska (Russian: Podkamennaya Tunguska, literally Understone Tunguska) is a river in Siberia; it is a right tributary of the Yenisei... Krasnoyarsk Krai (Russian: ) (2002 pop. ... is the 181st day of the year (182nd in leap years) in the Gregorian calendar. ... Year 1908 (MCMVIII) was a leap year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Tuesday of the 13-day-slower Julian calendar). ... is the 168th day of the year (169th in leap years) in the Gregorian calendar. ... The Julian calendar was a reform of the Roman calendar which was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 ab urbe condita). ...


The explosion was most likely caused by the air burst of a large meteoroid or comet fragment at an altitude of 5–10 kilometres (3–6 miles) above Earth's surface. Different studies have yielded varying estimates for the object's size, with general agreement that it was a few tens of metres across.[3] An air burst occurs whenever an explosive device such as an anti-personnel artillery shell or a nuclear weapon is detonated in the air instead of on contact with the ground or target or a delayed armor piercing explosion. ... Meteor redirects here. ... Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ... “km” redirects here. ... “Miles” redirects here. ... This article is about Earth as a planet. ...


Although the meteor or comet burst in the air rather than directly hitting the surface, this event is still referred to as an impact. Estimates of the energy of the blast range from 5 megatons[4] to as high as 30 megatons[5] of TNT, with 10–15 megatons the most likely[5] - about 1000 times as powerful as the bomb dropped on Hiroshima, Japan and about one third the power of Tsar Bomba.[6] The explosion knocked over an estimated 80 million trees over 2,150 square kilometres (830 square miles). It is estimated that the earthquake from the blast would have measured 5.0 on the Richter scale, which was not yet developed at the time. An explosion of this magnitude is capable of destroying a large metropolitan area.[7] This possibility has helped to spark discussion of asteroid deflection strategies. Artists impression of a major impact event. ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ... R-phrases S-phrases Related Compounds Related compounds picric acid hexanitrobenzene Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Trinitrotoluene (TNT) is a chemical compound with the formula C6H2(NO2)3CH3. ... The mushroom cloud over Hiroshima after the dropping of Little Boy. ... Tsar Bomba (, literally Emperor Bomb) is the Western name for the RDS-220 hydrogen bomb (codenamed Иван (Ivan) by its developers) — the largest, most powerful nuclear weapon ever detonated. ... Square kilometre (U.S. spelling: square kilometer), symbol km², is a decimal multiple of SI unit of surface area square metre, one of the SI derived units. ... A square mile is an English unit of area equal to that of a square with sides each 1 statute mile (≈1,609 m) in length. ... The Richter magnitude scale, or more correctly local magnitude ML scale, assigns a single number to quantify the amount of seismic energy released by an earthquake. ... This article does not cite any references or sources. ... Artists impression of a major impact event. ...


The Tunguska event is believed to be the largest impact event on land in Earth's recent history;[8] impacts of similar size in remote ocean areas would have gone unnoticed before the advent of global satellite monitoring in the 1960s and 1970s. Artists impression of a major impact event. ... This article is about Earth as a planet. ...

Contents

Description

Approximate location of the Tunguska event in Siberia.
Approximate location of the Tunguska event in Siberia.

At around 7:17 a.m. local time, Tungus natives and Russian settlers in the hills northwest of Lake Baikal observed a column of bluish light, nearly as bright as the Sun, moving across the sky. About 10 minutes later, there was a flash and a sound similar to artillery fire. Eyewitnesses closer to the explosion reported the sound source moving east to north. The sounds were accompanied by a shock wave that knocked people off their feet and broke windows hundreds of miles away. The majority of eyewitnesses reported only the sounds and the tremors, and not the sighting of the explosion. Eyewitness accounts differ as to the sequence of events and their overall duration. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... This article is about Siberia as a whole. ... The Evenks or Evenki (obsolete: Tungus or Tunguz, autonym: Эвэнки, Evenki) are a nomadic Tungusic people of Northern Asia. ... Baikal redirects here. ... Sol redirects here. ... Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ...


The explosion registered on seismic stations across Eurasia. Although the Richter scale was not developed until 1935, in some places the shock wave would have been equivalent to an earthquake of 5.0 on the Richter scale[citation needed]. It also produced fluctuations in atmospheric pressure strong enough to be detected in Great Britain. Over the next few weeks, night skies were aglow such that one could read in their light, from dust suspended in the stratosphere by the explosion. In the United States, the Smithsonian Astrophysical Observatory and the Mount Wilson Observatory observed a decrease in atmospheric transparency that lasted for several months, also from the suspended dust. Seismology (from the Greek seismos(σεισμός) = earthquake and λόγος,logos = knowledge ) is the scientific study of earthquakes and the propagation of elastic waves through the Earth. ... For other uses, see Eurasia (disambiguation). ... The Richter magnitude scale, or more correctly local magnitude ML scale, assigns a single number to quantify the amount of seismic energy released by an earthquake. ... Atmospheric pressure is the pressure at any given point in the Earths atmosphere. ... Atmosphere diagram showing stratosphere. ... The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution headquartered in Cambridge, Massachusetts, where it is joined with the Harvard College Observatory (HCO) to form the Harvard-Smithsonian Center for Astrophysics (CfA). ... The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California. ... Atmospheres redirects here. ...


The Guinness Book of World Records (1966 edition) states that due to the rotation of Earth, if the collision had occurred 4 hours 47 minutes later, it would have completely destroyed the Imperial Russian capital, Saint Petersburg. The Guinness Book of Records (or in recent editions Guinness World Records, and in previous US editions Guinness Book of World Records) is a book published annually, containing an internationally recognized collection of superlatives: both in terms of human achievement and the extrema of the natural world. ... Year 1966 (MCMLXVI) was a common year starting on Saturday (link will display full calendar) of the 1966 Gregorian calendar. ... The subject of this article was previously also known as Russia. ... Saint Petersburg (Russian: Санкт-Петербу́рг, English transliteration: Sankt-Peterburg), colloquially known as Питер (transliterated Piter), formerly known as Leningrad (Ленингра́д, 1924–1991) and Petrograd (Петрогра́д, 1914–1924), is a city located in Northwestern Russia on the delta of the river Neva at the east end of the Gulf of Finland...


Selected eyewitness reports

Artist conception of the event as described by witness Semen Semenov.
  • Testimony of S. Semenov, as recorded by Leonid Kulik's expedition in 1930.[9]

"At breakfast time I was sitting by the house at Vanavara trading post (65 kilometres/40 miles south of the explosion), facing North. [...] I suddenly saw that directly to the North, over Onkoul's Tunguska road, the sky split in two and fire appeared high and wide over the forest (as Semenov showed, about 50 degrees up - expedition note). The split in the sky grew larger, and the entire Northern side was covered with fire. At that moment I became so hot that I couldn't bear it, as if my shirt was on fire; from the northern side, where the fire was, came strong heat. I wanted to tear off my shirt and throw it down, but then the sky shut closed, and a strong thump sounded, and I was thrown a few yards. I lost my senses for a moment, but then my wife ran out and led me to the house. After that such noise came, as if rocks were falling or cannons were firing, the earth shook, and when I was on the ground, I pressed my head down, fearing rocks would smash it. When the sky opened up, hot wind raced between the houses, like from cannons, which left traces in the ground like pathways, and it damaged some crops. Later we saw that many windows were shattered, and in the barn a part of the iron lock snapped." Leonid Alekseevich Kulik (1883–April 24th, 1942) was a Russian mineralogist who is noted for his research into meteorites. ...

  • Testimony of Chuchan of Shanyagir tribe, as recorded by I.M.Suslov in 1926.[10]

"We had a hut by the river with my brother Chekaren. We were sleeping. Suddenly we both woke up at the same time. Somebody shoved us. We heard whistling and felt strong wind. Chekaren said, 'Can you hear all those birds flying overhead?' We were both in the hut, couldn't see what was going on outside. Suddenly, I got shoved again, this time so hard I fell into the fire. I got scared. Chekaren got scared too. We started crying out for father, mother, brother, but no one answered. There was noise beyond the hut, we could hear trees falling down. Chekaren and I got out of our sleeping bags and wanted to run out, but then the thunder struck. This was the first thunder. The Earth began to move and rock, wind hit our hut and knocked it over. My body was pushed down by sticks, but my head was in the clear. Then I saw a wonder: trees were falling, the branches were on fire, it became mighty bright, how can I say this, as if there was a second sun, my eyes were hurting, I even closed them. It was like what the Russians call lightning. And immediately there was a loud thunderclap. This was the second thunder. The morning was sunny, there were no clouds, our Sun was shining brightly as usual, and suddenly there came a second one! "Chekaren and I had some difficulty getting out from under the remains of our hut. Then we saw that above, but in a different place, there was another flash, and loud thunder came. This was the third thunder strike. Wind came again, knocked us off our feet, struck against the fallen trees. "We looked at the fallen trees, watched the tree tops get snapped off, watched the fires. Suddenly Chekaren yelled 'Look up' and pointed with his hand. I looked there and saw another flash, and it made another thunder. But the noise was less than before. This was the fourth strike, like normal thunder. "Now I remember well there was also one more thunder strike, but it was small, and somewhere far away, where the Sun goes to sleep."

"On the 17th of June, around 9 in the AM, we observed an unusual natural occurrence. In the N Karelinski village (200 verst N of Kirensk) the peasants saw to the North-West, rather high above the horizon, some strangely bright (impossible to look at) bluish-white heavenly body, which for 10 minutes moved downwards. The body appeared as a "pipe", i.e. a cylinder. The sky was cloudless, only a small dark cloud was observed in the general direction of the bright body. It was hot and dry. As the body neared the ground (forest), the bright body seemed to smudge, and then turned into a giant billow of black smoke, and a loud knocking (not thunder) was heard, as if large stones were falling, or artillery was fired. All buildings shook. At the same time the cloud began emitting flames of uncertain shapes. All villagers were stricken with panic and took to the streets, women cried, thinking it was the end of the world. "The author of these lines was meantime in the forest about 6 verst N of Kirensk, and heard to the NE some kind of artillery barrage, that repeated in intervals of 15 minutes at least 10 times. In Kirensk in a few buildings in the walls facing north-east window glass shook." is the 183rd day of the year (184th in leap years) in the Gregorian calendar. ... Year 1908 (MCMVIII) was a leap year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Tuesday of the 13-day-slower Julian calendar). ... A verst (Russian versta, верста) is an obsolete Russian unit of length. ... This article is about waves in the most general scientific sense. ... A verst (Russian versta, верста) is an obsolete Russian unit of length. ...

"When the meteorite fell, strong tremors in the ground were observed, and near the Lovat village of the Kansk uezd two strong explosions were heard, as if from large-caliber artillery." is the 208th day of the year (209th in leap years) in the Gregorian calendar. ... Year 1908 (MCMVIII) was a leap year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Tuesday of the 13-day-slower Julian calendar). ... Uyezd was a division of guberniya. ...

"Kezhemskoe village. On the 17th an unusual atmospheric event was observed. At 7:43 the noise akin to a strong wind was heard. Immediately afterwards a horrific thump sounded, followed by an earthquake which literally shook the buildings, as if they were hit by a large log or a heavy rock. The first thump was followed by a second, and then a third. Then - the interval between the first and the third thumps were accompanied by an unusual underground rattle, similar to a railway upon which dozens of trains are traveling at the same time. Afterwards for 5 to 6 minutes an exact likeness of artillery fire was heard: 50 to 60 salvoes in short, equal intervals, which got progressively weaker. After 1.5 - 2 minutes after one of the "barrages" six more thumps were heard, like cannon firing, but individual, loud, and accompanied by tremors. "The sky, at the first sight, appeared to be clear. There was no wind and no clouds. However upon closer inspection to the North, i.e. where most of the thumps were heard, a kind of an ashen cloud was seen near the horizon which kept getting smaller and more transparent, and possibly by around 2-3 p.m. completely disappeared." is the 194th day of the year (195th in leap years) in the Gregorian calendar. ... Year 1908 (MCMVIII) was a leap year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Tuesday of the 13-day-slower Julian calendar). ...

History

There was little scientific curiosity about the impact at the time, possibly due to the isolation of the Tunguska region. If there were any early expeditions to the site, the records were likely to have been lost during the subsequent chaotic years — World War I, the Russian Revolution of 1917, and the Russian Civil War. “The Great War ” redirects here. ... The Russian Revolution of 1917 was a series of political and social upheavals in Russia, involving first the overthrow of the tsarist autocracy, and then the overthrow of the liberal and moderate-socialist Provisional Government, resulting in the establishment of Soviet power under the control of the Bolshevik party. ... Combatants Local Soviet powers led by Russian SFSR and Red Army Chinese mercenaries White Movement Central Powers (1917-1918): Austria-Hungary Ottoman Empire German Empire Allied Intervention: (1918-1922) Japan Czechoslovakia Greece  United States  Canada Serbia Romania UK  France Foreign volunteers: Polish Italian Local nationalist movements, national states, and decentralist...


The first recorded expedition arrived at the scene more than a decade after the event. In 1921, the Russian mineralogist Leonid Kulik, visiting the Podkamennaya Tunguska River basin as part of a survey for the Soviet Academy of Sciences, deduced from local accounts that the explosion had been caused by a giant meteorite impact. He persuaded the Soviet government to fund an expedition to the Tunguska region, based on the prospect of meteoric iron that could be salvaged to aid Soviet industry. Mineralogy is an earth science that involves the chemistry, crystal structure, and physical (including optical) properties of minerals. ... Leonid Alekseevich Kulik (1883–April 24th, 1942) was a Russian mineralogist who is noted for his research into meteorites. ... Russian Academy of Sciences: main building Russian Academy of Sciences (Росси́йская Акаде́мия Нау́к) is the national academy of Russia. ... Artists impression of a major impact event. ... CCCP redirects here. ... Bacubirito in Culiacan, Mexico is second largest meteorite in the Americas, fifth largest in the world A meteorite is a relatively small extra-terrestrial body that reaches the Earths surface. ...

Photograph from the Soviet Academy of Science 1927 expedition led by Leonid Kulik.
Photograph from the Soviet Academy of Science 1927 expedition led by Leonid Kulik.

Kulik's party reached the site in 1927. To their surprise, no crater was to be found. There was instead a region of scorched trees about 50 kilometres (30 miles) across. A few near ground zero were still strangely standing upright, their branches and bark stripped off. Those farther away had been knocked down in a direction away from the center. Image File history File linksMetadata Download high-resolution version (2409x1846, 573 KB) Description: Trees were knocked down and burned over hundreds of square km by the Tunguska meteoroid impact Note: This image is public domain, from the Leonid Kulik expedition in 1927 Source: [1] License: File links The following pages... Image File history File linksMetadata Download high-resolution version (2409x1846, 573 KB) Description: Trees were knocked down and burned over hundreds of square km by the Tunguska meteoroid impact Note: This image is public domain, from the Leonid Kulik expedition in 1927 Source: [1] License: File links The following pages... Year 1927 (MCMXXVII) was a common year starting on Saturday (link will display full calendar) of the Gregorian calendar. ... Tycho crater on Earths moon. ... Ground zero is the exact location on the ground where any explosion occurs. ...


During the next ten years there were three more expeditions to the area. Kulik found a little "pothole" bog that he thought might be the crater, but after a laborious exercise in draining the bog, he found there were old stumps on the bottom, ruling out the possibility that it was a crater. In 1938, Kulik arranged for an aerial photographic survey of the area,[14] which revealed that the event had knocked over trees in a huge butterfly-shaped pattern. Despite the large amount of devastation, there was no crater to be seen. Lütt-Witt Moor, a bog in Henstedt-Ulzburg in northern Germany. ... Tree stump (about 37 years after felling) A tree stump on the Wicklow Mountains. ... Year 1938 (MCMXXXVIII) was a common year starting on Saturday (link will display the full calendar) of the Gregorian calendar. ...


Expeditions sent to the area in the 1950s and 1960s found microscopic glass spheres in siftings of the soil. Chemical analysis showed that the spheres contained high proportions of nickel and iridium, which are found in high concentrations in meteorites, hinting that they were of extraterrestrial origin. Analytical chemistry is the analysis of material samples to gain an understanding of their chemical composition and structure. ... For other uses, see Nickel (disambiguation). ... This article is about the chemical element. ... Willamette Meteorite A meteorite is a natural object originating in outer space that survives an impact with the Earths surface without being destroyed. ...


Detailed systematic eyewitness reports began to be gathered as late as 1959, when interviews were conducted with many of the indigenous people who had been within 100 kilometres (60 miles) of the explosion. Most of these accounts claimed that the local people had been covered with boils after the explosion, with whole families dying.[citation needed] The medical scientists attached to the expedition concluded that there had been an epidemic of smallpox in the area at the time.[citation needed] Boil or furuncle is a skin disease caused by the inflammation of hair follicles, thus resulting in the localized accumulation of pus and dead tissues. ... This article is about the disease. ...


Earth impactor

Meteoroid airburst

In scientific circles, the leading explanation for the explosion is the airburst of a meteoroid 6–10 kilometres (4–6 miles) above Earth's surface. Meteor redirects here. ...


Meteoroids enter Earth's atmosphere from outer space every day, usually travelling at a speed of more than 10 kilometres per second (6 miles/sec or 21,600 mph). Most are small but occasionally a larger one enters. The heat generated by compression of air in front of the body (ram pressure) as it travels through the atmosphere is immense and most meteoroids burn up or explode before they reach the ground. Since the second half of the 20th century, close monitoring of Earth's atmosphere has led to the discovery that such meteoroid airbursts occur rather frequently. A stony meteoroid of about 10 metres (30 ft) in diameter can produce an explosion of around 20 kilotons, similar to that of the Fat Man bomb dropped on Nagasaki, and data released by the U.S. Air Force's Defense Support Program indicate that such explosions occur high in the upper atmosphere more than once a year. Tunguska-like megaton-range events are much rarer. Eugene Shoemaker estimated that such events occur about once every 300 years. Atmospheres redirects here. ... Layers of Atmosphere - not to scale (NOAA)[1] Outer space, sometimes simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. ... For other uses, see Heat (disambiguation) In physics, heat, symbolized by Q, is energy transferred from one body or system to another due to a difference in temperature. ... In physics, ram pressure is pressure exerted on a body which is moving at supersonic velocity through a fluid medium. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ... This article is about the nuclear weapon used in World War II. For other uses, see Fat Man (disambiguation). ... The mushroom cloud over Hiroshima after the dropping of Little Boy. ... USAF redirects here. ... Painting of a DSP satellite on station. ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ... Eugene Shoemaker at a stereoscopic microscope used for asteroid discovery Eugene Shoemaker wearing a Bell rocket belt while training astronauts. ...


Blast patterns

The explosion's effects on the trees near ground zero was replicated during atmospheric nuclear tests in the 1950s and 1960s. These effects are caused by the shock wave produced by large explosions. The trees directly below the explosion are stripped as the blast wave moves vertically downward, while trees further away are knocked over because the blast wave is travelling closer to the horizontal when it reaches them. Preparation for an underground nuclear test at the Nevada Test Site in the 1980s. ... Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ...


Soviet experiments performed in the mid-1960s, with model forests (made of matches) and small explosive charges slid downward on wires, produced butterfly-shaped blast patterns strikingly similar to the pattern found at the Tunguska site. The experiments suggested that the object had approached at an angle of roughly 30 degrees from the ground and 115 degrees from north and had exploded in mid-air.[citation needed] For other uses, see Match (disambiguation). ...


Asteroid or comet?

The composition of the Tunguska body remains a matter of controversy. In 1930, the British astronomer F.J.W. Whipple suggested that the Tunguska body was a small comet. A cometary meteorite, being composed primarily of ice and dust, could have been completely vaporized by the impact with the Earth's atmosphere, leaving no obvious traces. The comet hypothesis was further supported by the glowing skies (or "skyglows" or "bright nights") observed across Europe for several evenings after the impact, possibly explained by dust and ice that had been dispersed from the comet's tail across the upper atmosphere.[5] The cometary hypothesis gained a general acceptance amongst Soviet Tunguska investigators by the 1960s.[5] Francis John Welsh Whipple (1876-1943) was a British mathematician and meteorologist. ... Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ... This article is about water ice. ... Look up dust in Wiktionary, the free dictionary. ... For other uses, see Europe (disambiguation). ...


In 1978, Slovak astronomer Ľubor Kresák suggested that the body was a fragment of the short-period Comet Encke, which is responsible for the Beta Taurid meteor shower; the Tunguska event coincided with a peak in that shower,[15] and the approximate trajectory of the Tunguska impactor is consistent with what would be expected from such a fragment.[5] It is now known that bodies of this kind explode at frequent intervals tens to hundreds of kilometres above the ground. Military satellites have been observing these explosions for decades.[16] Ľubor Kresák (1927 – 1994) was a Slovak astronomer. ... Comet Encke (officially designated 2P/Encke) is a periodic comet, named after Johann Franz Encke, who through laborious study of its orbit and many calculations was able to link multiple observations in 1786 (2P/1786 B1), 1795 (2P/1795 V1), 1805 (2P/1805 U1) and 1818 (2P/1818 W1) to... A meteor shower, some of which are known as a meteor storm or meteor outburst, is a celestial event where a group of meteors are observed to radiate from one point in the sky. ...


In 1983, astronomer Zdeněk Sekanina published a paper criticizing the comet hypothesis. He pointed out that a body composed of cometary material, travelling through the atmosphere along such a shallow trajectory, ought to have disintegrated, whereas the Tunguska body apparently remained intact into the lower atmosphere. Sekanina argued that the evidence pointed to a dense, rocky object, probably of asteroidal origin. This hypothesis was further boosted in 2001, when Farinella, Foschini, et al. released a study suggesting that the object had arrived from the direction of the asteroid belt. For other uses, see Asteroid (disambiguation). ... For other uses, see Asteroid (disambiguation). ...


Proponents of the comet hypothesis have suggested that the object was an extinct comet with a stony mantle that allowed it to penetrate the atmosphere.


The chief difficulty in the asteroid hypothesis is that a stony object should have produced a large crater where it struck the ground, but no such crater has been found. It has been hypothesized that the passage of the asteroid through the atmosphere caused pressures and temperatures to build up to a point where the asteroid abruptly disintegrated in a huge explosion. The destruction would have to have been so complete that no remnants of substantial size survived, and the material scattered into the upper atmosphere during the explosion would have caused the skyglows. Models published in 1993 suggested that the stony body would have been about 60 metres across, with physical properties somewhere between an ordinary chondrite and a carbonaceous chondrite. Tycho crater on Earths moon. ... A specimen of the NWA 869 chondrite (type L4-6), showing chondrules and metal flakes Chondrites are stony meteorites that have not been modified due to melting or differentiation of the parent body. ... Some carbonaceous chondrites. ...


Christopher Chyba and others have proposed a process whereby a stony meteorite could have exhibited the behavior of the Tunguska impactor. Their models show that when the forces opposing a body's descent become greater than the cohesive force holding it together, it blows apart, releasing nearly all its energy at once. The result is no crater, and damage distributed over a fairly wide radius, all of the damage being blast and thermal.


During the 1990s, Italian researchers extracted resin from the core of the trees in the area of impact, to examine trapped particles that were present during the 1908 event. They found high levels of material commonly found in rocky asteroids and rarely found in comets.[17][18] This article does not cite any references or sources. ...


Lake Cheko

In June of 2007 it was announced that scientists from the University of Bologna had identified a lake in the Tunguska region as a possible impact crater from the event. Lake Cheko is a small bowl shaped lake approximately 8 kilometres north-north-west of the hypocenter.[19] The hypothesis has been challenged by other impact crater specialists.[20] A 1961 investigation had dismissed a modern origin of Lake Cheko, saying that the presence of metres thick silt deposits at the lake's bed suggests an age of at least 5000 years.[21] Work is still being done at Lake Cheko to determine its origins.[22] The University of Bologna (Italian: , UNIBO) is the oldest continually operating degree-granting university in the world, and the second biggest university in Italy. ... For other uses, see Lake (disambiguation). ... Lake Cheko is a small freshwater lake in Siberia, near the Tunguska River. ... For other uses, see Silt (disambiguation). ...


Speculative hypotheses

Scientific understanding of the behaviour of meteorites in the Earth's atmosphere was much sparser during the early decades of the 20th century. Due to this lack of knowledge, as well as a paucity of scientific data about Tunguska due to Soviet secrecy during the Cold War, a great many other hypotheses for the Tunguska event have sprung up, none of which are accepted by the scientific community. For other uses, see Cold War (disambiguation). ...


End of the World?

Perhaps the earliest widely-held theory for the Tunguska explosion was that the world was about to end. As the minutes passed, this theory was dropped in favour of other, less final theories, until today one is hard-pressed to find anyone who truly believes the world ended on the morning of 30 June 1908...[23]

According to G. K. Kulesh, head of the Kirensk Meteorological Station[24]

The peasants of the village [of Korelina] were so stunned by the crashes that they sent a deputation to town to the local archpriest to ask if the end of the world was beginning, [and] how they were preparing for it in Kirensk.

Natural H-bomb

In 1989, D'Alessio and Harms suggested that some of the deuterium in a comet entering the Earth's atmosphere may have undergone a nuclear fusion reaction,[25] leaving a distinctive signature in the form of carbon-14. They concluded that any release of nuclear energy would have been almost negligible. Independently, in 1990, César Sirvent proposed that a deuterium comet, i.e., a comet with an anomalous high concentration of deuterium into its composition, could have exploded as a natural hydrogen bomb, generating most of the energy released. The sequence would be first a mechanical or kinetic explosion, triggering a thermonuclear reaction. These proposals are inconsistent with knowledge both of the composition of comets and of the temperature and pressure conditions necessary for initiating a nuclear fusion reaction.[26] Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance in the oceans of Earth of approximately one atom in 6500 of hydrogen (~154 PPM). ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing sustainable fusion power. ...


Black hole

In 1973, Albert A. Jackson and Michael P. Ryan, physicists at the University of Texas, proposed that the Tunguska event was caused by a "small" (around 1020 g to 1022 g) black hole passing through the Earth.[27] This hypothesis fails, as there was no so-called "exit event" — a second explosion occurring as the black hole, having tunneled through the Earth, shot out the other side on its way back into space - nor were there the continuous seismic disturbances that would occur along the hole's path through the mantle. The University of Texas System comprises fifteen educational institutions in Texas, of which nine are general academic universities, and six are health institutions. ... For other uses, see Black hole (disambiguation). ... Earth cutaway from core to exosphere. ...


The hypothesis was used by Larry Niven in his science fiction story The Borderland of Sol, and by David Brin, in his novel Earth, as well as by Bill DeSmedt in his novel Singularity. It also figures in Dan Simmons's Hyperion novels. This article does not cite any references or sources. ... Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Wikipedia does not have an article with this exact name. ... Glen David Brin, Ph. ... Cover of 1991 Spectra mass market paperback edition. ... Bill DeSmedt is an American author of science fiction. ... Singularity is a novel by Bill DeSmedt published by Per Aspera Press on November 8, 2004. ... Origin Hyperion is a Titan from Greek mythology. ...


Antimatter

In 1965, Cowan, Atluri, and Libby suggested that the Tunguska event was caused by the annihilation of a chunk of antimatter falling from space.[28] However, as with the other hypotheses described in this section, this does not account for the mineral debris left in the area of the explosion. Furthermore, there is no astronomical evidence for the existence of such chunks of antimatter in our region of the universe. If such objects existed, they should be constantly producing energetic gamma rays due to annihilation against the interstellar medium, but such gamma rays have not been observed. For other senses of this term, see antimatter (disambiguation). ... For other uses, see Astronomy (disambiguation). ... For other uses, see Universe (disambiguation). ... This article is about electromagnetic radiation. ... The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. ...


UFO crash

Various UFO aficionados have claimed that the Tunguska event was the result of an exploding alien spaceship or even an alien weapon going off to "save the Earth from an imminent threat". These claims appear to originate from a science fiction story penned by Soviet engineer Alexander Kazantsev in 1946, in which a nuclear-powered Martian spaceship, seeking fresh water from Lake Baikal, blew up in mid-air. This story was inspired by Kazantsev's visit to Hiroshima in late 1945. UFO redirects here. ... Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Alexander Petrovitch Kazantsev (02 September 1906 - 13 September 2002) was a popular Soviet sci-fi author. ... Baikal redirects here. ... For other uses, see Hiroshima (disambiguation). ...


Many events in Kazantsev's tale were subsequently confused with the actual occurrences at Tunguska. The nuclear-powered UFO hypothesis was adopted by TV drama critics Thomas Atkins and John Baxter in their book The Fire Came By (1976). The 1998 television series The Secret KGB UFO Files (Phenomenon: The Lost Archives), broadcast on Turner Network Television, referred to the Tunguska event as "the Russian Roswell" and claimed that crashed UFO debris had been recovered from the site. In 2004, a group from the Tunguska Space Phenomenon Public State Fund claimed to have found the wreckage of an alien spacecraft at the site.[29] A television program is the content of television broadcasting. ... Turner Network Television, usually referred to as TNT, is an American cable TV network created by media mogul Ted Turner and currently owned by the Turner Broadcasting System division of Time Warner. ... Roswell Daily Record, July 8, 1947, announcing the capture of a flying saucer. ...


The proponents of the UFO hypothesis have never been able to provide any significant evidence for their claims. It should be noted that the Tunguska site is downrange from the Baikonur Cosmodrome and has been contaminated repeatedly by Russian space debris, most notably by the failed launch of the fifth Vostok test flight on December 22, 1960. The payload landed close to the Tunguska impact site, and a team of engineers was dispatched there to recover the capsule and its two canine passengers (who survived). Map showing the location of Baikonur Cosmodrome in Kazakhstan The Baikonur Cosmodrome (Kazakh: Байқоңыр ғарыш айлағы, Bayqoñır ğarış aylağı; Russian: Космодром Байконур, Kosmodrom Baykonur), also called Tyuratam, is the worlds oldest and largest operational space launch facility. ... Vostok spacecraft model The Vostok programme (Восто́к, translated as East) was a Soviet human spaceflight project that succeeded in putting a person into Earth orbit for the first time. ... is the 356th day of the year (357th in leap years) in the Gregorian calendar. ... Year 1960 (MCMLX) was a leap year starting on Friday (link will display full calendar) of the Gregorian calendar. ...


Similar events

The Tunguska event is the strongest, but not the only, significant meterorite airburst in recent history. A selection of similar events follows. This list is quite biased, since recording of meteorite explosive yields is relatively recent:

Date Place Yield of explosion (TNT equivalent) Height of explosion Remarks
June 30, 1908 60 kilometres westnorthwest of Vanavara, at 60°55' N, 101°57'E in Krasnoyarsk Krai, Imperial Russia 10–15 Mt 8.5 km Tunguska event
August 13, 1930 Curuçá River Area, Amazonas, Brazil 0.1-1.0 Mt
May 31, 1965 Southeast Canada 600 t 13 km 1g material from meteorite found
September 17, 1966 Lake Huron, Michigan, United States 600 t 13 km No material from meteorite found
February 5, 1967 Vilna Alberta, Canada 600 t 13 km Two very small fragments found - 48 mg and 94 mg.

Stored at University of Alberta, in Edmonton. [30] Unit of energy commonly used to quantify laerge amounts of energy. ... is the 181st day of the year (182nd in leap years) in the Gregorian calendar. ... Year 1908 (MCMVIII) was a leap year starting on Wednesday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Tuesday of the 13-day-slower Julian calendar). ... Krasnoyarsk Krai (Russian: ) (2002 pop. ... The subject of this article was previously also known as Russia. ... is the 225th day of the year (226th in leap years) in the Gregorian calendar. ... Year 1930 (MCMXXX) was a common year starting on Wednesday (link will display 1930 calendar) of the Gregorian calendar. ... is the 151st day of the year (152nd in leap years) in the Gregorian calendar. ... Year 1965 (MCMLXV) was a common year starting on Friday (link will display full calendar) of the 1965 Gregorian calendar. ... is the 260th day of the year (261st in leap years) in the Gregorian calendar. ... Year 1966 (MCMLXVI) was a common year starting on Saturday (link will display full calendar) of the 1966 Gregorian calendar. ... Ipperwash Beach, Lake Huron. ... This article is about the U.S. State. ... is the 36th day of the year in the Gregorian calendar. ... Year 1967 (MCMLXVII) was a common year starting on Sunday (link will display full calendar) of the 1967 Gregorian calendar. ...

September 22, 1979 Southern Indian Ocean 2 kt
January 19, 1993 Lugo, Northern Italy > 10 kt > -20a
September 25, 2002 Bodaybo, Russia 0.5 – 5 kt
June 6, 2002 Mediterranean Sea between Libya and Greece 26 kt

is the 265th day of the year (266th in leap years) in the Gregorian calendar. ... Also: 1979 by Smashing Pumpkins. ... Orthographic projection centered on the Prince Edward Islands, the location of the Vela incident The Vela Incident (sometimes known as the South Atlantic Flash) was an as-yet unidentified flash of light detected by a United States Vela satellite on September 22, 1979. ... is the 19th day of the year in the Gregorian calendar. ... Year 1993 (MCMXCIII) was a common year starting on Friday (link will display full 1993 Gregorian calendar). ... is the 268th day of the year (269th in leap years) in the Gregorian calendar. ... Also see: 2002 (number). ... The Vitim event or Bodaybo event is believed to be an impact by a bolide or comet nucleus in the Vitim River basin. ... is the 157th day of the year (158th in leap years) in the Gregorian calendar. ... Also see: 2002 (number). ... The Eastern Mediterranean Event was a high-energy aerial explosion over the Mediterranean Sea, around 34ºN 21ºE (between Libya, Greece and Crete) on June 6th, 2002. ...

Tunguska event in fiction

The Tunguska event was an explosion that occurred on June 30, 1908 in the Siberian region of Russia. ...

See also

Artists impression of a major impact event. ... The Cando event was an explosion that ocurred in the village of Cando, Spain, in the morning of January 18, 1994. ... Artists reconstruction of a major impact event. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 km (11 mi) above the hypocenter. ... The Eastern Mediterranean Event was a high-energy aerial explosion over the Mediterranean Sea, around 34ºN 21ºE (between Libya, Greece and Crete) on June 6th, 2002. ... Lonar crater in the Buldhana district of Maharashtra state, India is the largest crater in basaltic rock. ... Orthographic projection centered on the Prince Edward Islands, the location of the Vela incident The Vela Incident (sometimes known as the South Atlantic Flash) was an as-yet unidentified flash of light detected by a United States Vela satellite on September 22, 1979. ... The Vitim event or Bodaybo event is believed to be an impact by a bolide or comet nucleus in the Vitim River basin. ...

References

  • Baxter, John and Thomas Atkins, The Fire Came By: The Riddle of the Great Siberian Explosion, Macdonald and Jane's, London 1975. ISBN 044689396X.
  • Brown, J.C, and Hughes, D.W. Nature 268, 512–514 (1977)
  • Furneaux, Rupert. The Tungus Event, Nordon Publications, New York, 1977. ISBN 058604423X.
  • Gallant, Roy A. The Day the Sky Split Apart: Investigating a Cosmic Mystery, Atheneum Books for Children, New York, 1995. ISBN 0689803230.
  • Krinov, E. L. Giant Meteorites, trans. J.S. Romankiewicz (Part III: The Tunguska Meteorite), Pergamon Press, Oxford, 1966
  • Kundt, W. Current Science. 81. 399-407 (2001) [1]
  • Morgan, J. Phipps, Ranero, C.R., Reston, T.J. Earth and Planetary Science Letters. 217. 263-284 (2004)
  • Lerman, J. C., Mook, W. G. & Vogel, J. C. Nature, Effect of the Tunguska Meteor and Sunspots on Radiocarbon in Tree Rings, (9 December 1967) | doi:10.1038/216990a0; 216, 990–1 (1967)[2]
  • Ol'khovatov, A.Yu. Earth, Moon and Planets, v.93, pp.163–173 (2003)
  • Stoneley, Jack. Cauldron of Hell: Tunguska, Simon and Schuster, New York, 1977. ISBN 0671229435.
  • Verma, Surendra. The Tunguska Fireball: Solving One of the Great Mysteries of the 20th century, Icon Books, Cambridge, 2005. ISBN 1840466200.
  • Verma, Surendra. The Mystery of the Tunguska Fireball, Icon Books, Cambridge, 2006. ISBN 1840467282.

Notes

  1. ^ P. Farinella, L. Foschini, Ch. Froeschlé, R. Gonczi, T. J. Jopek, G. Longo, P. Michel Probable asteroidal origin of the Tunguska Cosmic Body
  2. ^ a b Trayner, C. Perplexities of the Tunguska meteorite
  3. ^ Lyne, J.E., Tauber, M. The Tunguska Event
  4. ^ Sandia supercomputers offer new explanation of Tunguska disaster. Sandia National Laboratories (2007-12-17). Retrieved on 2007-12-22.
  5. ^ a b c d e Shoemaker, Eugene (1983), Asteroid and Comet Bombardment of the Earth, vol. 11, US Geological Survey, Flagstaff, Arizona: Annual Review of Earth and Planetary Sciences, doi:10.1146/annurev.ea.11.050183.002333, <http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.ea.11.050183.002333?prevSearch=Tunguska> 
  6. ^ Verma (2005), p1.
  7. ^ Longo, Giuseppe (2007), “18”, in Bobrowsky, Peter T. & Rickman, Hans, Comet/Asteroid Impacts and Human Society, An Interdisciplinary Approach, Berlin Heidelberg New York: Springer-Verlag, pp. 303-330, ISBN 3-540-32709-6 
  8. ^ APOD: 2007 November 14 - Tunguska: The Largest Recent Impact Event
  9. ^ N. V. Vasiliev, A. F. Kovalevsky, S. A. Razin, L. E. Epiktetova (1981). Eyewitness accounts of Tunguska (Crash)., Section 6, Item 4
  10. ^ Vasiliev, Section 5
  11. ^ Vasiliev, Section 1, Item 2
  12. ^ Vasiliev, Section 1, Item 3
  13. ^ Vasiliev, Section 1, Item 5
  14. ^ Longo G.. The 1938 aerophotosurvey. Retrieved on 2008-01-03.
  15. ^ The Tunguska object - A fragment of Comet Encke. Astronomical Institutes of Czechoslovakia. Retrieved on 2007-02-15.
  16. ^ Nemtchinov, I.V.; C. Jacobs and E. Tagliaferri (1997). "Analysis of Satellite Observations of Large Meteoroid Impacts". Annals of the New York Academy of Sciences 822: 303-317. 
  17. ^ Longo, G.; Serra R., Cecchini S. and Galli M., (1994). "Search for microremnants of the Tunguska Cosmic Body.". Planetary and Space Science 42 (2): 163-177. UK: Elsevier Science Ltd. 
  18. ^ Serra, R.; Cecchini S. and Galli M, and Longo G. (1994). "Experimental hints on the fragmentation of the Tunguska cosmic body.". Planetary and Space Science 42 (9): 777-783. UK: Elsevier Science Ltd. 
  19. ^ "A possible impact crater for the 1908 Tunguska Event", Department of Physics, University of Bolongna
  20. ^ Rincon Paul (2007) "Team makes Tunguska crater claim", BBC (2007-06-27)
  21. ^ Florenskiy, K P (1963). "Preliminary results from the 1961 combined Tunguska meteorite expedition". Meteoritica 13. 
  22. ^ Crater From 1908 Russian Space Impact Found, Team Says
  23. ^ K. Zahnle, Nature 383, 674-75 (1996)
  24. ^ :Quoted in N. V. Vasilyev et al., Pokazaniya Ochevidtsev Tungusskogo Padeniya (Testimony of Eyewitnesses to the Tunguska Impact), VINITI (1981), available on line at http://olkhov.narod.ru/tungwitn1.htm or at http://tunguska.tsc.ru/ru/science/1/0. This document is in Russian, but a translation of Kulesh's full report may be found at http://www.vurdalak.com/tunguska/witness/kulesh_gk.htm.
  25. ^ The nuclear and aerial dynamics of the Tunguska Event
  26. ^ Universiteit Leiden - "Making a comet nucleus" - By Greenberg, J.M. 1998
  27. ^ “Was the Tungus Event due to a Black Hole?” Nature, vol. 245, September 14, 1973, pp. 88-89.
  28. ^ Cowan, C., Atluri, C. R. & Libby, Possible Anti-Matter Content of the Tunguska Meteor of 1908. Nature 206, 861 - 865 (29 May 1965); doi:10.1038/206861a0
  29. ^ SPACE.com - "Russian Alien Spaceship Claims Raise Eyebrows, Skepticism "
  30. ^ Vilna

It has been suggested that Sandia Base be merged into this article or section. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... December 17 is the 351st day of the year (352nd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 356th day of the year (357th in leap years) in the Gregorian calendar. ... Eugene Shoemaker at a stereoscopic microscope used for asteroid discovery Eugene Shoemaker wearing a Bell rocket belt while training astronauts. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance with the Gregorian calendar. ... is the 3rd day of the year in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 46th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 178th day of the year (179th in leap years) in the Gregorian calendar. ... Kirill Pavlovich Florensky (December 27, 1915—April 9, 1982) was a Russian geologist and astronomer. ...

External links

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Coordinates: 60°55′N, 101°57′E The University of Bologna (Italian: , UNIBO) is the oldest continually operating degree-granting university in the world, and the second biggest university in Italy. ... Map of Earth showing lines of latitude (horizontally) and longitude (vertically), Eckert VI projection; large version (pdf, 1. ...


  Results from FactBites:
 
Tunguska Comet Impact - 1908 (2258 words)
In accordance to strict final official position of Committee of meteorites of Russian Academy of Sciences (was stated in 1962, chairman - famous astronomer, academician V.G.Fesenkov) comet nature of Tunguska event was determined with conclusion of mainly southern direction of motion of meteor body (mainly from south to north).
The distortion of Tunguska's trajectory was produced mainly by russian astronomer and member of Committee of meteorites V.A.Bronshten in the middle of XX century.
Tunguska debate in the Institute for Dynamics of Geospheres (Russian Academy of Sciences) The meeting devoted to theoretical aspects of the Tunguska problem was held in the Institute for Dynamics of Geospheres (April 26, 1999).
Cool Science Facts: The Tunguska Event (356 words)
At 7:17 in the morning on June 30th, 1908, a huge explosion occurred several miles in the air above the Tunguska region of Siberia, with the force of a large nuclear blast.
The scientists persuaded the government to fund the expedition, based on the assumption that iron from the meteorite could be retrieved and used by Soviet industry.
Although impact events like these are statistically quite improbable, there is nevertheless a small possibility that at any moment, without warning, the city that you live in could be completely wiped out by a big rock from space.
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