Tunguska event

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Forest damage caused by the Tunguska event
(photo from 1929)

The Tunguska event consisted of one or more very large explosions (hence the Tunguska explosion ) on June 30, 1908 in the Siberian Yenisseisk Governorate , today's Krasnoyarsk region , the cause of which has not yet been clarified beyond doubt. The event took place near the Stony Tunguska River (Podkamennaya Tunguska) in the Evenki settlement area .

The most likely cause is the entry of an asteroid - the Tunguska asteroid named after the region  - or a small comet into the earth's atmosphere , where it exploded a few kilometers above the ground. According to more recent findings, a volcanic eruption cannot be ruled out.

procedure

Tunguska Event (Russia)
Tunguska event
Tunguska event
Location of the Tunguska event

Most eyewitnesses report an explosion on June 17th jul. / June 30, 1908 greg. around 7:15 a.m., some of them from several to fourteen explosions. It is reported that the phenomenon lasted for a while, giving the impression of a trajectory of a light-colored body. In the event, trees up to about 30 kilometers away were uprooted and windows and doors were dented in the commercial settlement of Wanawara, 65 kilometers away . Experts estimate that around 60 million trees were knocked over in an area of ​​over 2000 km². Even at a distance of over 500 kilometers, a bright glow of fire, a strong vibration, a pressure wave and a thunderous noise were perceived, among others by travelers on the Trans-Siberian Railway . The residents of Kirensk, 450 km from the scene of the event, saw a fountain rise, from which the height of the fountain is estimated to be at least 20 km. Due to the sparsely populated area, there are no reliable reports of injuries or deaths. Depending on the source, killed reindeer and no or up to two human victims are mentioned.

In all meteorological stations in Europe and North America, the seismograph recorded the tremors in the earth's crust. The pressure wave propagating at the speed of sound reached Irkutsk, 970 km away, in one hour, Potsdam , 5000 km away, in 4 hours, 42 minutes and Washington, DC in 8 hours. The measuring devices in Potsdam received the signals a second time after 30 hours and 29 minutes after having circled the earth once. During the following nights, silver shining clouds of extraordinary sheen appeared over the middle latitudes of Europe. The transparency of the atmosphere was clouded by the mass of dust that was blown up. Despite these diverse effects, the event received little attention among scientists, which is probably also due to the communication possibilities of the 20th century, which are still in their infancy.

Depiction of the Tunguska meteorite and the geologist Kulik on a Soviet postage stamp on the occasion of the 50th anniversary of the event

The Russian mineralogist Leonid Kulik collected initial information on an expedition in 1921/1922, but only got as far as Kansk , 600 kilometers from the site of the explosion. It was not until 1927 that a major expedition from the Soviet Academy of Sciences , led by Kulik, was able to advance to the devastated area. They found an area about 25 km in diameter with great devastation. Large, strong, mostly hundred-year-old trees had been uprooted, their treetops pointing away from the site of the impact.

The crew of the Graf Zeppelin airship searched in vain for a crater when it circumnavigated the earth in August 1929 . In 1937/1938, Kulik arranged for aerial photographs of the region. The photos taken from an airplane showed two impact sites in the destroyed forest and confirmed the unusual direction in which the trees fell.

The coordinate of the presumed "epicenter", determined from the directions in which the trees fell, is 60 ° 53 ′ 9 ″  N , 101 ° 53 ′ 40 ″  E (other information: 60 ° 53 ′ 11 ″  N , 101 ° 55 ′ 11 ″  E ), the height of the event above the earth's surface is estimated at 5 to 14 kilometers. The seismic and barometric recordings indicated a time at approximately 12:14 a.m. Universal Time (7:14 a.m. local time ).

Scientists investigated the area until 1940. Kulik found very fine rock debris in the peat layers that covered the swamp, but the age or origin of which could not be determined more precisely. Molten pieces of quartz were also taken from the ground, in which nickel-iron compounds were found.

The Second World War prevented further search work.

Strength

Estimates of explosive power vary widely. In the 1980s they still assumed up to 50 megatons of TNT . More recent calculations assume an explosive effect comparable to 2 to 4, maximum 5 megatons of TNT. The reason for this could have been a powerful jet of hot air that would continue its way to the ground after the explosion of a comet at a height, causing a stronger pressure wave and higher temperatures there.

Hypotheses

Impact hypotheses

The cause of the event is still unclear. The most likely entry of a stone asteroid, or comet, of low density and 30 to 80 meters in diameter, which exploded about five to fourteen kilometers above the ground and therefore did not cause a crater . In 1978 the Slovak astronomer Ľubor Kresák proposed that the Tunguska event could have been triggered by a fragment of the periodic comet Encke .

However, model calculations showed that comets "fizzle out" higher up in the atmosphere. Iron meteoroids , in contrast to stone meteorids , reach the earth's surface more intact and more frequently when they fly through the earth's atmosphere. Although they can disintegrate, they do not cause such an explosive phenomenon.

To date, no fragments of an impacted celestial body (impactor) visible to the naked eye have been found. A smaller depression was interpreted by Kulik as a crater, but this has not been confirmed. The search for microscopic dust-like remnants of the impactor or chemical and isotopic anomalies, as would be expected if extraterrestrial material were to enter, has so far yielded little success. Microscopic particles, diamond dust, graphite fragments and molten iron and nickel granules were found. According to theoretical estimates of the possible orbits of the Tunguska bolide , a stone asteroid is most likely, although a comet cannot be completely excluded here either. The results of a Tunguska expedition in 1999 support the view of the meteorite impact.

In June 2007, after an expedition led by marine geologist L. Gasperini, an Italian research group published their assumption in the online journal Terra Nova that Lake Cheko was the crater of an impactor. The lake is about 8 kilometers north of the epicenter and could have come from a fragment of the original bolide. In January 2017, Russian scientists may have disproved the theory that Lake Cheko is the crater of the Tunguska event, as their research indicates that it was formed over 280 years ago.

Just a few hours after the Tunguska incident, a meteorite fall was observed in a Ukrainian village near Kiev . A connection was suggested between the meteorite found (L6 chondrite weighing 1.9 kg, named after the place where it was found , Kagarlyk ) and the Tunguska event, because of the otherwise unlikely temporal clash. However, measurements of the irradiation age of Kagarlyk showed a value of 16.2 million years, which is very typical for L6 chondrites. It is therefore unlikely that Kagarlyk split off from the Tunguska object just before the explosion, as Steel had assumed; Kagarlyk seems to have more of the same origin as the other L6 chondrites.

In 2013, extraterrestrial fragments that had already been found in the area in 1978 were analyzed. Further investigations are still pending.

Geophysical hypotheses

The Soviet scientist Andrei Olchowatow favored in the late 1980s a purely geophysical interpretation of the Tunguska event. He was followed by the German astrophysicist Wolfgang Kundt , who advocated the thesis that it was a volcano-like eruption. According to this, the event could be explained as an explosion of 10 million tons of natural gas , which escaped through cracks from an underground natural gas reservoir under high pressure until it rose into high layers of the atmosphere at high speed, ignited by static electricity and burned down in a flame front down to the point of exit. This would explain the various directions of movement of the bright luminous phenomenon reported by witnesses. A slight earthquake and strange atmospheric glowing phenomena observed in the days before the explosion could also be related. It is also reported that there were unusually bright night skies in Europe and Asia in the days following the event. In London, for example, it was possible to read a newspaper in this light.

However, this theory cannot easily explain the brightness of the explosion, since the luminance of a gas burning in atmospheric oxygen is hardly greater than that of a candle flame, and it does not emit such intense heat radiation as was actually perceived by many people. Therefore, gas combustion requires a very large flame volume to explain the light and heat radiation observed in Wanawara 65 kilometers away.

Another hypothesis is that the Tunguska event was a more recent Verneshot event (a volcanic eruption caused by massive pressure build-up of gas beneath the crust of a craton ). The place where the event took place is in the middle of the Siberian Trapps , a large area of igneous rock that formed around the turn of the Permian and Triassic (at this point around 252 million years ago, the largest known mass extinction in Earth's history took place , in which 75% of the terrestrial and 95% of the marine invertebrates became extinct, see Perm-Triassic border ). More recent work suggests a circular depression below the trap, which, according to the hypothesis, would be a prerequisite for the creation of a Verneshot. According to the verneshot model that would kratonische earth's crust beneath the region form a weak point of the emergence of a Kimberlitröhre  - which were actually found in other places means Siberia - or a micro-Verne Shots allow, so an eruption of volcanic gas, which is then in the atmosphere ignited. However, this hypothesis is controversial, and the Tunguska event is only cited as a possible example of a Verneshot.

Outsider hypotheses

After more than a hundred years there is no reliable explanation of the cause, there are also a number of exotic hypotheses that have not found scientific recognition. Among other things, the impact of a small black hole , the crash of an extraterrestrial spaceship or an explosion of the mosquitoes found there , comparable to a dust explosion , the " mosquito explosion ", were made responsible for the event. Another theory links the Tunguska event to Nikola Tesla's experiments on radio frequency energy transmission . Since 1898 he experimented on a method for wireless energy transmission through the ionosphere . For this purpose, at the time of the event in 1908, he used the experimental facility of the Wardenclyffe Tower in Long Island , USA, which was specially built in 1901 . According to another theory of the particle physicist Robert Foot from the University of Melbourne, it could also have been a collision of the earth with a space body made of mirror matter (a hypothetical form of matter, of which e.g. dark matter could consist).

Presentation in different media

The Tunguska event is thematized or fictionalized in numerous novels, films, pieces of music and games.

Novels

  • 1908: Georg Heym was referring to the Tunguska event as the Apocalypse in his diary and the poem The Clouds I . According to Gunnar Decker Georg Heym , vbb-Verlag, Berlin 2011, p. 142 f.
  • 1951: Stanisław Lem processed the Tunguska event in his novel The Astronauts . He describes the explosion of a spaceship that originated from a civilization residing on Venus. In the film adaptation of the novel, The Silent Star , the explosion is interpreted as the crash of a spaceship belonging to the Venus residents.
  • 1965: The Strugazki brothers put in the book Monday begins on Saturday a humorous fantastic thesis that the Tunguska event was caused by a "counter-red" spaceship traveling backwards on the time axis: it landed on earth, ignited on landing the taiga and then wandered further back through time so that no traces were left at the scene of the fire.
  • 1996: Wolfgang Hohlbein combines the real event of 1908 over the area of ​​the Steinige Tunguska River in his esoteric fantasy novel The Return of the Magicians with a fictional plot in which 80 years later a young journalist comes across the story and learns that the explosion caused the Gate to another dimension has been opened.
  • 2005: In Peter Schwindt's novel The Portal from the Justin Time series , the event is caused by the crash of an antimatter-powered satellite that was part of a time portal with which a mad scientist wanted to achieve world domination.
  • 2006: Thomas Pynchon's novel Against the Day gives several explanations for the Tunguska event, including a meteorite impact, an alien visit, and a misdirected energy beam from Nikola Tesla's experiments on wireless energy transmission . There is no mention of whether any of these should be considered a "correct" explanation.
  • 2008: In Christian Kracht's alternative world-historical novel I will be here in the sunshine and in the shade , the Tunguska event triggers the turning point in the parahistoric plot, as Lenin does not return from Switzerland to Russia, which is irradiated by the event, about the Russian Revolution to bring about, but instead turned Switzerland into a socialist soviet republic.

philosophy

  • 2011: Michael Hampe uses the Tunguska event in Tunguska or the end of nature as a hook for complex natural philosophical considerations, some of which are presented in a resumption of the traditional philosophical-literary form of the conversation with the dead.

Games

comics

  • 2008: In Achim Stößer's cartoon series Pater Anselm's space mission, the spaceship gets caught up in a time vortex, whereupon the anti-nuclear reactor has to be thrown off because there is a risk of a core meltdown, thus triggering the Tunguska event.

TV series

See also

literature

  • John Baxter, Thomas Atkins: Like a Second Sun: The Enigma of the Siberian Meteor. Econ-Verlag, Düsseldorf 1977, ISBN 3-430-11232-X .
  • Michael Hampe: Tunguska or the end of nature. Carl Hanser Verlag, Munich 2011, ISBN 978-3-446-23767-4 .
  • Vladimir Rubtsov: The Tunguska Mystery. Springer, Dordrecht 2009, ISBN 978-0-387-76573-0 .
  • Solvejg Nitzke: The production of the catastrophe. The Tunguska Event and Modern Programs. transcript-Verlag, Bielefeld 2017, ISBN 978-3-8376-3657-4 .

Web links

Commons : Tunguska Event  - collection of pictures, videos and audio files

German

English

Individual evidence

  1. ^ Markus Becker: Historical explosion. Tunguska puzzle before solution - trail leads to the crater. Spiegel Online, accessed February 23, 2010 .
  2. ↑ Ulf von Rauchhaupt: Tunguska asteroid. Fireworks over the taiga. FAZ-Net, online edition of the Frankfurter Allgemeine Zeitung, accessed on February 23, 2010 .
  3. ^ A b c Axel Bojanowski : Historical event. Fire rockets from the ground exploded taiga. Spiegel Online, accessed December 13, 2010 .
  4. ↑ Nature, Vol. 440, March 23, 2006, p. 390; doi: 10.1038 / 440390a .
  5. ^ Ian Ridpath: Tunguska: The final answer. Published in: New Scientist , August 11, 1977, Vol. 75, No 1064, p. 346.
  6. ^ C. Gritzner: Human Casualties in Impact Events. In: WGN. Journal of the International Meteor Organization , October 1997, Vol. 25: 5, pp. 222-226. bibcode : 1997JIMO ... 25..222G .
  7. ↑ a b c d The Tungus Cameteorite, in an unspecified East German illustrated magazine from 1962 (cut out).
  8. ↑ Eric Niderost: Zeppelin World Cruise: Globe Trotting Leviathan. Aviation History / HistoryNet.com, July 1993 / November 6, 2006 (English).
  9. ↑ VG Fast: Statisticheskij analiz parametrov Tungusskogo vyvala . In: Izdatelstvo Tomskogo Universiteta (ed.): Problema Tungusskogo meteorita, part 2 . Tomsk 1967, p. 40-61 .
  10. ↑ AV Zolotov: Problema Tungusskoj katastrofy 1908 g. In: Nauka i tekhnika . Minsk 1969.
  11. ↑ Vladimir Rubtsov: The Tunguska Mystery . 2009, ISBN 978-0-387-76573-0 .
  12. ↑ Peter Horn: 102 years after the Tunguska event. Catastrophic collisions of cosmic bodies with the earth . In: Bernd Herrmann (Ed.): Contributions to the Göttingen Environmental History Colloquium 2009–2010 . 2010, ISBN 978-3-941875-52-4 , pp. 109-140 ( oapen.org ).
  13. ↑ Thomas Bührke: Tunguska catastrophe: tiny with force. Online edition of the Süddeutsche Zeitung, December 19, 2007, accessed on February 23, 2010 (online article, printed on December 20, 2007).
  14. ↑ Meteorite impact in Siberia 100 years ago. Neue Zürcher Zeitung, online edition (NZZ-Online), June 30, 2008, accessed on February 23, 2010 .
  15. ↑ VG Fesenkov : Pomutneniye atmosfery, proizvedennoye padeniyem Tungusskogo meteorita 30 iyunya 1908 g . In: Meteoritika . tape 6 , 1949, pp. 8-12 .
  16. ↑ Harlow Shapley : Flight from chaos. A survey of material systems from atoms to galaxies . McGraw-Hill, New York 1930.
  17. ↑ Leonid Kulik : Dannyje po Tungusskomu meteoritu k 1939 godu . In: Doklady Akad. Nauk SSSR . tape 22 (8) , 1939, pp. 520-524 .
  18. ^ Ľubor Kresák : The Tunguska object - A fragment of Comet Encke. Astronomical Institutes of Czechoslovakia 29, 1978, p. 129, bibcode : 1978BAICz..29..129K .
  19. ↑ P. Farinella, L. Foschini, Ch. Froeschl, R. Gonczi, TJ Jopek, G. Longo, P. Michel: Probable asteroidal origin of the Tunguska Cosmic Body . In: Astronomy and Astrophysics . tape 377 , 2001, p. 1081-1097 , bibcode : 2001A & A ... 377.1081F (English, PDF; 2.4 MB ).
  20. ↑ L. Gasperini, F. Alvisi et al. a .: A possible impact crater for the 1908 Tunguska Event. In: Terra Nova. 19, 2007, pp. 245-251, doi: 10.1111 / j.1365-3121.2007.00742.x .
  21. ^ Günter Paul: But a crater in the taiga? FAZ-Net, online edition of the Frankfurter Allgemeine Zeitung, accessed on February 23, 2010 (text published in issue No. 147, June 28, 2007, p. 34).
  22. ↑ Luca Gasperini, Enrico Bonatti, Giuseppe Longo: The day on which the sky parted. Spiegel Online, June 27, 2008, accessed February 23, 2010 .
  23. ↑ Beautiful and mysterious: but was Lake Cheko formed from the exploding Tunguska meteorite? January 23, 2017, accessed January 29, 2017 .
  24. ^ A b D. Steel: Tunguska and the Kagarlyk meteorite . In: The Observatory . Vol. 115, No. 1126 , 1995, pp. 136 .
  25. ↑ O. Eugster, E. Polnau, D. Terribilini: Cosmic ray and gas retention ages of newly recovered and of unusual chondrites . In: Earth and Planetary Science Letters . tape 164 , 1998, pp. 511-519 .
  26. ↑ Rock samples suggest meteor caused Tunguska blast. In: nature.com.
    New evidence of meteoritic origin of the Tunguska cosmic body. bibcode : 2013P & SS ... 84..131K .
  27. ↑ Researchers claim reexamination of rock samples confirms meteoritic origin of Tunguska cosmic body. In: phys.org. Retrieved May 30, 2014.
  28. ↑ Andrei Yu. Ol'khovatov: The tectonic interpretation of the 1908 Tunguska event. (No longer available online.) Archived from the original on October 23, 2007 ; accessed on February 23, 2010 (English, summary of January 26, 2005, detailed version October 4, 2006 ).
  29. ^ Wolfgang Kundt: The 1908 Tunguska catastrophe . In: Current Science Association in collaboration with the Indian Academy of Sciences (Ed.): Current Science . tape 81 , 2001, p. 399–407 ( The 1908 Tunguska catastrophe: An alternative explanation. PDF file; 250 kB. ( Memento of February 29, 2008 in the Internet Archive ) [accessed on February 23, 2010]).
  30. ^ Wolfgang Kundt: Tunguska 1908 . In: Chinese Journal of Astronomy & Astrophysics . tape 3 , 2003, p. 545–554 ( PDF ( memento of July 25, 2011 in the Internet Archive )). Tunguska 1908 ( Memento of the original from July 25, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.chjaa.org
  31. ^ Nigel Watson: The Tunguska Event . In: History Today . tape 58.7 , July 2008, p. 7 ( online short version ).
  32. ↑ J. Phipps Morgan, TJ Reston, and CR Ranero: Contemporaneous mass extinctions, continental flood basalts, and 'impact signals': Are mantle plume-induced lithospheric gas explosions the causal link? In: Earth and Planetary Science Letters . tape 217 , 2004, pp. 263–284 ( cornell.edu [PDF; 705 kB ]).
  33. ↑ L. Hryanina: The bouquet of the meteorite craters in the epicenter of Tunguska impact in 1908 year . In: Lunar and Planetary Science Conferences . tape 30 , 1999.
  34. ^ Robert Lomas: The Man Who Invented the Twentieth Century. Nikola Tesla, Forgotten Genius of Electricity . Headline, London 2000, ISBN 0-7472-6265-9 .
  35. ↑ Rudi Berner: In a word: A journey to the summit of philosophy, Version V5.1 (complete revision, May 2010), p. 49, ISBN 978-3-940119-45-2 .
  36. ^ R. Foot: The mirror world interpretation of the 1908 Tunguska event and other more recent events . In: arXiv: hep-ph / 0107132 . July 11, 2001, arxiv : hep-ph / 0107132 .
  37. ↑ Space mission: 1908 - Tunguska. In: antitheismus.de. Retrieved March 25, 2017 .