Editing Tunguska event (section)

==Description==
[[File:Russia-CIA WFB Map--Tunguska.png|thumb|Location of the event in [[Siberia]] (modern map)]]
On 30 June 1908 [[adoption of the Gregorian calendar#Adoption in Eastern Europe|N.S.]] (cited as 17 June 1908 [[Julian calendar|O.S.]] before the implementation of the [[Soviet calendar]] in 1918), at around 7:17 am local time, [[Evenkis|Evenki]] natives and Russian settlers in the hills northwest of [[Lake Baikal]] observed a bluish light, nearly as bright as the [[Sun]], moving across the sky and leaving a thin trail. Closer to the horizon, there was a flash producing a billowing cloud, followed by a pillar of fire that cast a red light on the landscape. The pillar split in two and faded, turning to black. About ten minutes later, there was a sound similar to artillery fire. Eyewitnesses closer to the explosion reported that the source of the sound moved from the east to the north of them. The sounds were accompanied by a [[shock wave]] that knocked people off their feet and broke windows hundreds of kilometres away.<ref name=jenniskens/>

The explosion registered at [[seismology|seismic stations]] across Eurasia, and air waves from the blast were detected in Germany, Denmark, Croatia, and the United Kingdom &ndash; and as far away as [[Batavia, Dutch East Indies]], and Washington, D.C.<ref name=":0">{{cite journal|last1=Whipple|first1=F. J. W.|title=On Phenomena related to the great Siberian meteor|journal=Quarterly Journal of the Royal Meteorological Society|date=10 September 2007|volume=60|issue=257|pages=505–522|doi=10.1002/qj.49706025709|bibcode=1934QJRMS..60..505W}}</ref> It is estimated that, in some places, the resulting shock wave was equivalent to an earthquake measuring 5.0 on the [[Richter scale]].<ref name=Traynor2>{{cite journal|last=Traynor|first=Chris|title=The Tunguska Event|journal=[[Journal of the British Astronomical Association]]|volume=107|issue=3|year=1997|pages=111–130|url=https://britastro.org/journal/journal-of-the-british-astronomical-association-vol-107-iss-3|url-access=subscription}}</ref> 

Over the next few days, night skies in Asia and Europe were aglow.<ref name="Watson">{{cite journal|last1=Watson|first1=Nigel|title=The Tunguska Event|journal=History Today|volume=58|issue=1|date=July 2008|page=7|url=https://www.historytoday.com/archive/months-past/tunguska-event}}</ref> There are contemporaneous reports of brightly lit photographs being successfully taken at midnight (without the aid of flashbulbs) in Sweden and Scotland.<ref name=":0" /> It has been theorized that this sustained glowing effect was due to light passing through high-altitude ice particles that had formed at extremely low temperatures as a result of the explosion &ndash; a phenomenon that decades later was reproduced by [[Space Shuttle]]s.<ref>{{cite press release|title=Space Shuttle Science Shows How 1908 Tunguska Explosion Was Caused By A Comet|url=https://www.sciencedaily.com/releases/2009/06/090624152941.htm|work=ScienceDaily|publisher=Cornell University|date=25 June 2009}}</ref><ref>{{cite journal|last1=Kelley|first1=M. C.|last2=Seyler|first2=C. E.|last3=Larsen|first3=M. F.|year=2009|title=Two-dimensional Turbulence, Space Shuttle Plume Transport in the Thermosphere, and a Possible Relation to the Great Siberian Impact Event|journal=Geophys. Res. Lett.|volume=36|issue=14|pages=L14103|doi=10.1029/2009GL038362|bibcode=2009GeoRL..3614103K|doi-access=free}}</ref> In the United States, a [[Smithsonian Astrophysical Observatory]] program at the [[Mount Wilson Observatory]] in California observed a months-long decrease in [[atmosphere|atmospheric]] transparency consistent with an increase in suspended dust particles.<ref>{{cite journal|last1=Turco|first1=R.P.|last2=Toon|first2=O.B.|last3=Park|first3=C.|last4=Whitten|first4=R.C.|last5=Pollack|first5=J.B.|last6=Noerdlinger|first6=P.|title=An analysis of the physical, chemical, optical, and historical impacts of the 1908 Tunguska meteor fall|journal=Icarus|date=April 1982|volume=50|issue=1|pages=1–52|doi=10.1016/0019-1035(82)90096-3|bibcode=1982Icar...50....1T}}</ref>

===Selected eyewitness reports===
[[File:Тунгус метеорит Топи Тунгуски до14сент1930 ВС1931.JPG|right|thumb|Tunguska marshes, around the area where it fell. This photo is from the magazine ''[[Vokrug sveta|Around the World]]'', 1931. The original photo was taken between 1927 and 1930 (presumptively no later than 14 September 1930).]]
Though the region of Siberia in which the explosion occurred was very sparsely populated in 1908, there are accounts of the event from eyewitnesses, and regional newspapers reported the event shortly after it occurred.

The testimony of S. Semenov, as recorded by Russian mineralogist [[Leonid Kulik]]'s expedition in 1930:<ref>N. V. Vasiliev, A. F. Kovalevsky, S. A. Razin, L. E. Epiktetova (1981). ''[http://tunguska.tsc.ru/ru/science/1/0 Eyewitness accounts of Tunguska (Crash).] {{Webarchive|url=https://web.archive.org/web/20070930161327/http://tunguska.tsc.ru/ru/science/1/0 |date=30 September 2007 }}'', Section 6, Item 4</ref>

{{Blockquote|At breakfast time I was sitting by the house at [[Vanavara (rural locality)|Vanavara]] Trading Post [approximately {{convert|65|km|mi}} 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 &ndash; 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 metres. 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.|sign=|source=}}

Testimony of Chuchan of the Shanyagir tribe, as recorded by I. M. Suslov in 1926:<ref>Vasiliev, Section 5</ref>

{{Blockquote|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, the 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 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.}}

''Sibir'' newspaper, 2 July 1908:<ref>Vasiliev, Section 1, Item 2</ref>

{{Blockquote|On the morning of 17th of June,<ref>[[Gregorian calendar]]: 30 June</ref> around 9:00, we observed an unusual natural occurrence. In the north Karelinski village [200 [[verst]] ({{convert|213|km|mi|abbr=on}}) north of Kirensk] the peasants saw to the northwest, 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 versts [6.4&nbsp;km] north of Kirensk and heard to the north-east some kind of artillery barrage, that repeated at intervals of 15 minutes at least 10 times. In Kirensk in a few buildings in the walls facing north-east window glass shook.}}

''Siberian Life'' newspaper, 27 July 1908:<ref>Vasiliev, Section 1, Item 3</ref>

{{Blockquote|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-calibre artillery.|sign=|source=}}

''Krasnoyaretz'' newspaper, 13 July 1908:<ref>Vasiliev, Section 1, Item 5</ref>

{{Blockquote|Kezhemskoye village. On the 17th an unusual atmospheric event was observed. At 7:43 the noise akin to a strong wind was heard. Immediately afterward a horrific thump sounded, followed by an earthquake that 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 was accompanied by an unusual underground rattle, similar to a railway upon which dozens of trains are travelling at the same time. Afterward, 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. 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.}}
[[File:Trajectory Models of The Tunguska Fireball.svg|thumb|center|800px|alt=Trajectory Models of The Tunguska Fireball|Tunguska's trajectory and the locations of five villages projected onto a plane normal to the Earth's surface and passing through the fireball's approach path. The scale is given by an adopted beginning height of 100&nbsp;km. Three zenith angles ZR of the apparent [[Radiant (meteor shower)|radiant]] are assumed and the trajectories plotted by the solid, dashed, and dotted lines, respectively. The parenthesized data are the distances of the locations from the plane of projection: a plus sign indicates the location is south-south west of the plane (i.e. toward the viewer); a minus sign, north-north east of it (i.e. away from the viewer). The transliteration of the village names in this figure and the text is consistent with that of Paper I and differs somewhat from the transliteration in the current world atlases.]]