At about 7 a.m. on June 30, 1908, over the Central Siberian forest near Vanovara on the Upper Tungus, a great incandescent mass was seen to fly through the air...Just before it struck the ground there was a terrific explosion...
Frank W. Lane (1945)
Had this meteorite fallen in Central Belgium there would have been no living creature left in the whole country; on London, none left alive south of Manchester or east of Bristol. Had it fallen on New York, Philadelphia might have escaped with only its windows shattered...
Leonid Kulik (1929)
1908 Tuesday, June 30
Kagarlyk, Ukraine, Russia. 7 a.m. A stone meteorite weighing almost two kilograms fell after a fireball.
Kansk, Siberia. (300 miles from Tunguska.) About 7.15 a.m. (local time), 00.14 (Greenwich Mean Time) A tanner, Sarychev, washing wool in a river, saw a round radiant body about half the size of the sun flash across the eastern sky. It was followed by a sharp bang, then subterranean rumblings.
Ilimsk, Siberia. (About 150 miles from Tunguska.) Polyuzhinsky, Director of the Ilimsk Observatory, heard thunder-like noises which ended in a crash and an earth tremor. A resident said he had seen 'a flying star with a fiery tail' which fell in the distance. Many inhabitants of the villages round Ilimsk had seen a fiery body shaped like a beam which passed across the sky from the south towards the north-west, followed by a tongue of fire and smoke on the horizon. Houses shook and explosions and bangs were heard.
Kezhma, Siberia. (About 125 miles from Tunguska.) A 'brilliant white elongated mass' followed by a broad white band was seen to cross the Sun and become broader until it was much larger than the Moon. The body descended towards a forest, accompanied by a thunderous roar. To the west of Kezhma, a ploughman saw a 'huge flame' shoot up beyond the forest to the north. Trees swayed in a hurricane-like wind. A wall of water swept up the Angara River. A. K. Kokorin, the observer at the Kezhma meteorological station, recorded the appearance of two huge fiery circles in the north at 7 a.m., followed four minutes later by a wind, then a battery of sounds like gunshots and cannon fire.
Vanavara, Siberia. (40 miles from Tunguska.) A resident, Semenov, said that 'the sky was split in two and its northern part was aflame'. He was forced to shield his eyes. There was a wave of intense heat and an air blast threw him several feet. The house shook, glass shattered, and the earth split. Semenov's daughter saw 'the sky to the north rent open to the ground and fire pour from the chasm.' Its light was brighter than the Sun. The sky closed and heavy explosions followed. Later analysis suggested that in bright daylight a column of fire 12 miles high and a mile wide had been seen from Vanavara, which became a mushroom-shaped cloud 50 miles high.
Boykit, Siberia. (100 miles north of Vanavara.) A flash of fire was seen to the south-east and loud bangs were heard.
Kansk, Siberia. 7.17 a.m. P. Sukhodaeff telegraphed the Central Seismic Commission in St. Petersburg, reporting several earth tremors which shook doors, windows and lamps. They were accompanied by subterranean rumblings.
Near Turokhansk. (600 miles from Tunguska.) Three or four 'dull thuds in succession, like distant artillery fire' were heard.
Petersfield, Hampshire. (3,500 miles from Tunguska.) 5.23 a.m. GMT. The microbarograph of Captain Charles Cave recorded the passage of four air waves, followed by many rapid oscillations. Napier Shaw's microbarograph, in Kensington also recorded at 5.23 a.m. 'four undulations...lasting about a quarter of an hour, and then violently interrupted by a sudden...explosive disturbance', travelling from northeast to south-west.
Holland. An 'undulating mass' was observed passing across the northwest horizon. 'It was not cloud, for the blue sky itself seemed to undulate'.
London. A 'bright red glow' in the sky after sunset.
Gothenburg, Sweden. An 'extraordinarily strong light', bright enough for a book to be read, appeared in the sky an hour after sunset and continued until after 2 a.m. on July 1.
Germany. 10 p.m. A greenish twilight became a glowing red rim on the horizon at midnight.
Antwerp, Belgium. After sunset, the 'ruddy glow of a huge fire rising above the horizon' made it possible to see the seconds hand of a watch.
Russia. Dusk. 'Enormous silver clouds were seen at an altitude of 83 kilometres (50 miles), which almost turned night into day throughout the continent'.
Aberdeen, Scotland. 10 p.m. The fading twilight suddenly grew brighter until it was 'almost as bright as daylight'.
Brancaster, Norfolk. 11 p.m. Holcombe Ingleby reported that 'the sky had the appearance of a dying sunset of exquisite beauty. This not only lasted but actually grew both in extent and intensity' until 2.30 a.m., when the sky clouded. At 1.45 a.m. 'the whole sky, N. and N.E. was a delicate salmon pink'.
London. Midnight. The sky was bright enough for newspapers to be read. The northern sky at midnight became light blue, and 'the clouds were touched with pink in so marked a fashion that police headquarters was rung up by several people who believed a big fire was raging in the north of London.'
Russia, 300 miles east of Moscow. Midnight. A student from Kazan University took street photographs at midnight.
Sky-glow and shining clouds: drawing from a photograph taken in Russia on the night of 30 June - 1 July, 1908
1908 Jone 30 – July 1
Glasgow, Scotland. 11 p.m. to 3 a.m. The sky was so luminous that only the brightest stars were visible.
1908 July 1
Godmanchester, Huntingdonshire. Midnight. Katharine Stephen, in a letter to the Times of July 2, described a 'strange light' which made the sky so bright that it was possible to read large print indoors. It was on the north-east horizon, and of 'a bright flame-colour' The sky above the light 'was blue as in the daytime' At 1.30 a.m. 'the room was quite light as if it had been day; the light in the sky was then more dispersed and was a fainter yellow.' On July 2, the Times reported; 'The Aurora Borealis was very brilliant again last night...All the outstanding features of (London) were silhouetted. Many people were in the suburban roads viewing the sight.'
A photograph with an exposure time of 20 seconds taken at 10.5 p.m., July 1, 1908 by George Embrey of Gloucester.
1908 July 2
Nizhne-Karelinsk, Siberia. (About 200 miles from Tunguska). On this date, a correspondent for the Kirensk or Irkutsk newspaper Sibir reported that, a few days earlier, a brilliant cylindrical body, shining with a dazzling bluish-white light, had been seen in the cloudless sky to the north-west. It moved vertically downwards for about 10 minutes. When the body neared the horizon 'it seemed to be pulverised', A huge cloud of black smoke was formed, with a crash like thunder. Buildings shook, and 'a forked tongue of flame broke through the cloud'. All the inhabitants of the village ran out into the street in panic.' The reporter had been in a forest just south of Kirensk, 250 kilometres (155 miles) south of Nizhne-Karelinsk, when he heard 'gunfire' for 10 or 15 minutes. Back at the town he found that north-west facing windows had been shattered and similar noises had been heard throughout the district. Peasants had seen 'a fast-moving red fireball streaking across the sky to the north-west'.
1908 July 4
Kansk, Central Siberia. A newspaper correspondent sent to the town to look into rumours of a meteor reported on this date that 'the noise was considerable, but no stone fell...There is no doubt that a meteorite fell, probably some distance away, but its huge mass and so on are very doubtful.'
The Times of this date discussed 'the remarkable ruddy glows which have been seen on many nights lately'. Some scientists believed that they were auroral, others that they were volcanic twilight glows. The Times said, 'no volcanic outburst of abnormal violence has been reported lately...the dust may have reached us...from some unreported eruption in some little-known region of the world.'
1908 July 13
Siberia. On this date the newspaper Krasnoyarets published a report from the village of Kenzma of a recent 'extraordinary atmospheric phenomenon'. A fiery body passed across the sky and touched the horizon, where 'a huge flame shot up that cut the sky in two.' A noise like a strong wind was followed by a 'fearful crash' and an earth shock. Then there was an 'underground roar' and 50 or 60 bangs.
1908 mid-July to mid-August
California. Measurements showed a 'noticeable decrease' in the transparency of the atmosphere between these dates.
The Registrar General's Report on the weather in England for 1908 said, 'At the end of June and the beginning of July, there was a very remarkable illumination of the northern sky for about two hours before and after midnight, when it was possible to read small print without the aid of artificial light. This phenomenon was witnessed over practically the whole of Europe.'
A merchant named Sudzdalev is said to have visited the explosion site and discovered diamonds.
Leonid A. Kulik, of the St. Petersburg Meteorological Museum read a newpaper cutting describing an incident on the trans-Siberian railway. 'About 8 a.m., in the middle of June 1908...a huge meteorite is said to have fallen in Tomsk...near Filomonovo Junction. Its fall was accompanied by a frightful roar and a deafening crash...the passengers poured out to examine the fallen object, but they were unable to study the meteorite closely because it was red hot...the meteorite was almost entirely buried in the ground...it was a stone block, whitish in colour, and as much as 6 cubic sagenes in size.' 1 sagene = 7 feet.
Siberia. Leonid Kulik, visited Kansk after collecting reports of the events of 1908. He decided that a meteorite must have fallen near the basin of the Stony Tunguska River.
Tunguska, Siberia. A geologist working in the Tunguska region met a man called Ilya Potapovich, who said that 15 years earlier, Potapovich's brother, living by the River Chambre, had his hut wrecked by a tremendous explosion, which flattened the forest for many miles along the river banks. A pit was formed in the devastated area. From the Podkamennaya Tunguska River to this pit and back was a 3-day reindeer journey.
Vanavara and Teterya trading stations, on the Tunguska River, Siberia. Evenki people interviewed by the ethnographer I. M. Suslov said that a fireball 'burned the trees, killed the dogs and the reindeer, injured people and flattened the taiga (forest)'.
A. V. Voznesensky, in the magazine Mirovedeniye, said the Tunguska explosion had been heard over an area of 380,000 square miles. He believed that the object was a meteorite, which, as there were a number of detonations, must have fragmented before reaching the ground. Sound phenomena were heard over a radius of 500 miles. Voznesensky said that the event had been seen and heard over an area larger than France and Germany combined. The fireball, which moved from south-south-west to north-north east. had been seen by thousands of people from Siberia's southern border to the Tunguska region. The body was probably a group of meteorites which 'were flying in the same direction and gradually breaking up'. A 'very considerable mass' fell to earth. Investigators might find 'something very similar to the meteorite crater of Arizona', surrounded by a mass of fragments.
1927 March 23
Vanavara, Siberia. Leonid Kulik's expedition to investigate the origin of the Tunguska explosion reached Vanavara, which at this date was a small outpost with a few shops and houses, situated on the high right bank of the Stony Tunguska River. He enlisted Ilya Potapovich as a guide. In an interview, a witness called Kosolapov described 'a huge fireball that covered an enormous part of the sky...an explosion...threw me several feet...the glass and framing in the house shattered'.
1927 April 13
Siberia. Kulik found the first signs of the devastated forest on the bank of the Makirta River, which was 'littered with the trunks of fallen birches and pines, apparently smashed down by the shock wave of the blast.'
The devastated forest
1927 April 15
Khladni ridge, Tunguska, Siberia. Kulik wrote in his diary, “From our observation point no sign of forest can be seen, for everything has been devastated and burned...One has an uncanny feeling when one sees 20 to 30-inch giant trees snapped across like twigs, and their tops hurled many yards away.' His guide Ilya Potapovich said, 'This is where the thunder and lightning fell down'.
1927 May 30
River Churgima, Siberia. Kulik reached the river mouth, then crossed hills encircling the 'Southern Swamp', After a preliminary survey, he wrote that he has 'circled the centre of the fall. With a fiery stream of hot gases and cold solid bodies, the meteorite had struck (and) wrought all this mighty havoc...The taiga...has been practically destroyed by being completely flattened. All the former vegetation...bears characteristic traces of uniformly continuous scorching...The area with scorch marks is estimated to be tens of miles across.' All the thousands, perhaps millions, of fallen trees radiated outward from a centre where scorched trees are still standing. Kulik said that all the old growth in an area tens of kilometres in diameter 'show the traces of an intense fire. This is unlike the usual fire and is found both on the fallen as well as on the standing trees...before the fall this was a normal green taiga...there have been no other fires in this area either before or after the fall and the fire that it caused...In literature on meteorites, if the evidence from chronicles is discounted, there have never been any descriptions of a firestorm produced by the fall of a meteorite, although there have been indications of firestorms in the past...'
Charles P. Oliver, in the Scientific American, (July 1928 – 'The Great Siberian Meteorite: An Account of the Most Remarkable Astronomical Event of the Twentieth Century') called the Tunguska explosion 'the most astonishing phenomenon of its kind in scientific annals...many accounts of events in old chronicles that have been laughed at as fabrications are far less miraculous than this one...' He said , 'Fortunately for humanity this meteoric fall happened in a region where there were no inhabitants...But if such a thing can happen in Siberia there is no known reason why the same could not happen in the United States'.
1928 June 23
Southern Swamp, Tunguska, Siberia. Kulik's second expedition investigated small round holes in the Southern Swamp, which he believed were caused by meteorite fragments. Nothing was found. Kulik determined the position of the fall as 60° 55' N., 100° 57' E.
Kulik's third Tunguska expedition left Leningrad. Drilling and digging in several crater-like formations failed to find any evidence that they had been caused by meteorite impact.
F. J. Whipple suggested that the Tunguska object had been a comet.
Kulik said that 'the whole mass of the original iron meteorite, before its encounter with the earth's atmosphere, was probably as much as several thousands of metric tons'.
1938 – 39
Kulik's last expedition into the Tunguska region succeeded in taking 'not entirely satisfactory' aerial photographs of the devastated area. They did show the radial direction of the shattered forest and confirmed the Southern Swamp as the centre of the explosion.
William H. Christie of the Mount Wilson Observatory, California, said, 'The night glows...remove all doubt as to the nature of the object which struck Earth. It was apparently a small comet...and the tail, or part of it, which was captured by the Earth formed the glows.'
Craters made by the Sikhote-Alin meteorites, 12 February 1947
1947 Wednesday, February 12
Sikhote-Alin Mountains, Siberia. 10.38 a.m. A fireball as large as the Moon passed across the sky, followed by a column of black smoke and an explosion that shook houses. 122 craters, some 30 feet deep and 80 feet wide, together with numerous fragments of meteoric iron, were later found.
Southern Swamp (or South Marsh). An aerial survey of the 'devastated zone' of the Tunguska explosion showed that the blast had descended from a height of several kilometres, felling about 40,000 trees over a radius of 70 km. (43 miles).
The geochemist Kirill Florensky visited the South Marsh and concluded that the round holes found by Kulik were sink-holes formed by thawing of the permafrost.
The Russian mineralogist A.A. Yavnel analysed soil samples brought back by Kulik's expeditions of 1929 and 1930. In some he found microscopic magnetite globules and small percentages of nickel and cobalt, suggesting that an iron meteorite had fallen on Tunguska. It was discovered later that the samples had been contaminated by material from the Sikhote-Alin meteorite fall of 1947, which had been stored with Kulik's samples.
Tunguska, Siberia. An expedition led by Professor Kirill P. Florensky spent 34 days searching 500 miles of forest for meteoric fragments or craters. Nothing was found.
1958 June 30
The USSR issued a special postage stamp to mark the 50th anniversary of Tunguska.
Leningrad. V. G. Fesenkov said that 'beyond all doubt', a comet, with a mass of at least a few million tons had exploded above the South Marsh.
The Russian science fiction writer Alexander Kasantev, in Visitor from the Cosmos, said that the only explanation for the Tunguska event was the accidental explosion of a nuclear-powered spacecraft. He had first put forward this idea in 1946, in a short story, 'The Blast', published in the magazine Vokrug Sveta.
Tomsk, Siberia. Dr. Gennady Plekhanov, of the Tomsk Medical Institute tested 300 soil samples and 100 plants from the Southern Swamp. He claimed that 'in the centre of the catastrophe radioactivity is one and a half to two times higher than that found 20 to 25 miles away.'
1961 – 62
Florensky led another expedition to Tunguska, which studied the forest devastation and established the trajectory of the fireball. He said that the body, moving at 18,000 kilometres an hour, was brought to a sudden stop 5 kilometres above the ground, causing explosive vaporisation. After the explosion the forest burned for at least 5 days.
1965 May 29
Clyde Cowan, C. R. Athuri and Willard F. Libby published an article in Nature, 'Possible Anti-Matter Content of the Tunguska Meteor of 1908'.
The orbit of the Tunguska object was calculated by Vasili Fesenkov of the Soviet Academy of Science's meteorite committee. He deduced that the object approached the Earth from behind the Sun, and was hidden by the Sun's glare, like the bright comet Mrkos (1957) which was not discovered until it had passed the Earth's orbit.
A. A. Jackson and Michael P. Ryan of Texas University suggested in Nature that the Tunguska explosion might have been caused by 'a black hole of substellar mass'. Such an object would heat the surrounding atmosphere to an extremely high temperature, creating a deep blue plasma column. Jackson and Ryan said that eye-witnesses described the object as a bright blue 'tube'. Had the object been a black hole, it should have passed through the Earth in about 15 minutes and emerged in the North Atlantic somewhere between 40 – 50° N. and 30 – 40° W. However, no record has been found of the disturbance such an emergence would cause.
The Israeli scientist Ari Ben-Manahem compared Tunguska seismograph records with nuclear airbursts from tests over Novaya Zemlya. He decided that the Tunguska explosion occurred 8.5 kilometres above the ground and was of about 12.5 megatons.
Igor Zotkin said, 'The hypothesis that best fits in with the information available is that the Tunguska body was a loose and not very strong aggregation containing a lot of volatile substances, as in the nuclei of comets'.
Encke’s Comet on November 9, 1871: a telescopic drawing by J. Carpenter. North is at the top.
L. Kresak presented a case for the Tunguska meteor being 'associated' with, and possibly a fragment of, the short-period Encke's Comet. The β-Taurid meteor shower, whose parent is Encke, reached a peak on June 30, 1908.
Zdenek Sekanina considered that the Tunguska object had been an asteroid 90 to 190 metres across. It moved from a direction nearly 110 degrees east of north, about 5 degrees above the horizon, at a velocity of about 108,000 km/h, and exploded, once, about 8 kilometres above the ground with a force in excess of 12 megatons.
Andrei Ol'khovatov, in the Izvestia Academy of Science, described his hypothesis that the Tunguska explosion was caused by a 'geometeor', created by unknown meteorological and geological processes. The explosion was preceded by meteor-like objects which. in the geometer hypothesis, were actually formed in the Earth's atmosphere and resembled ball lightning.
Christopher Chyba, Kevin Zahnle and Paul Thomas used computer simulations of the blown-down tree pattern at Tunguska to estimate the size of the explosion at about 15 megatons, 8 kilometres up. They ruled out comet nuclei and carbonaceous meteorites as the cause, which would explode too high in the atmosphere. An iron meteorite would strike the earth, forming a crater. Only a stony meteorite 'would create a Tunguska-like situation'.
2002 Tuesday, September 24
Near the Vitim River, Siberia. About 11.50 p.m. USAF satellites detected a meteor fireball and explosion. Explosive sounds were heard up to 60 kilometres away.
Scientists from Irkutsk reached the area of the Vitim River fall but were unable to locate the impact site at 58° 9' N., 113° 21' E. Witnesses had seen a 'sphere with a tail'.
An expedition reached the Vitim River impact site and found that 100 square kilometres of the taiga were flattened. A few kilometres away about 20 small craters, up to 20 metres across, were discovered.