The Tunguska event was a large explosion that occurred near the Stony Tunguska River, in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of 30 June 1908 (N.S.). The explosion over the sparsely populated Eastern Siberian Taiga flattened 2,000 km2 (770 sq mi) of forest yet caused no known human casualties. The explosion is generally attributed to the air burst of a meteoroid. It is classified as an impact event, even though no impact crater has been found; the object is thought to have disintegrated at an altitude of 5 to 10 kilometres (3 to 6 miles) rather than hit the surface of the Earth.
The Tunguska event is the largest impact event on Earth in recorded history. Studies have yielded different estimates of the meteoroid's size, on the order of 60 to 190 metres (200 to 620 feet), depending on whether the body was a comet or a denser asteroid.
Since the 1908 event, there have been an estimated 1,000 scholarly papers (most in Russian) published on the Tunguska explosion. In 2013, a team of researchers published analysis results of micro-samples from a peat bog near the center of the affected area showing fragments that may be of meteoritic origin.
Early estimates of the energy of the air burst range from 10–15 megatons of TNT (42–63 PJ) to 30 megatons of TNT (130 PJ), depending on the exact height of burst estimated when the scaling-laws from the effects of nuclear weapons are employed. However, modern supercomputer calculations that include the effect of the object's momentum find that more of the energy was focused downward than would be the case from a nuclear explosion and estimate that the airburst had an energy range from 3 to 5 megatons of TNT (13 to 21 PJ).8
The 15 megaton (Mt) estimate represents an energy about 1,000 times greater than that of the atomic bomb dropped on Hiroshima, Japan — roughly equal to that of the United States' Castle Bravo (15.2 Mt) ground-based thermonuclear detonation on 1 March 1954, and about one-third that of the Soviet Union's Tsar Bomba explosion on October 30, 1961 (which, at 50 Mt, was the largest nuclear weapon ever detonated).
It is estimated that the Tunguska explosion knocked down some 80 million trees over an area of 2,150 square kilometres (830 sq mi), and that the shock wave from the blast would have measured 5.0 on the Richter magnitude scale. An explosion of this magnitude would be capable of destroying a large metropolitan area, but, due to the remoteness of the location, no fatalities were documented. This event has helped to spark discussion of asteroid impact avoidance.
On 30 June 1908, at around 7:17 a.m. local time, Evenki natives and Russian settlers in the hills north-west of Lake Baikal observed a column of bluish light, nearly as bright as the Sun, moving across the sky. About ten minutes later, there was a flash and 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. The majority of witnesses reported only the sounds and tremors, and did not report seeing the explosion. Eyewitness accounts vary regarding the sequence and duration of the events. Wikipedia, Tunguska Event
Eyewitness Account?
At breakfast time I was sitting by the house at Vanavara Trading Post [approximately 65 kilometres (40 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—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.
Mysterious Spacecraft Joining Up With Newly Discovered “Mini Moon” In Orbit Around Earth Prompts Concerns contains review of Tunguska explosion, etc.
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Memories of French autonomous martyrs
Let's now turn to the written sources, that is to see how the "Moscow fire" is described by the French, which were at that time in the Russian capital. Here, for example, what Lieutenant Charles Artois of the Napoleon army wrote in his calendar.
On that day, the holy sun illuminated Moscow with golden light. Suddenly, a second sun appeared just above the real sun, it was so bright, it blinded my eyes. and he burned the face of Paul Burger, who was chilling on the balcony. Our house and roof started smoking, so we had to wash them with water. In other estates, that were closer to the "false sun", fires broke out.
A week later, after the second sun appeared, Paul wrote that all the officers and men started losing hair, that the men and horses were sick and weak, so the administration decided to leave Moscow and this is what happened im welcomed with great relief. Pavlos described the retreat as very strange. From his archive it seems that French soldiers suffered not only from Russian glaciers and Adartan raids, but first and foremost from some strange disease that had been affected in Moscow. Humans couldn't eat, covered in hatches and wounds, leading to hundreds of deaths every day, and horses were weak and falling. Paul Artois himself returned to France as a disability, resigned and soon died from the "Russian transmission" at the age of thirty two. According to the Moscow publication "Rossians and Napoleon Vonapartis" (1814), the French lost more than thirty thousand people during their seventy-day stay in Moscow, that is in Borontino. Why did this happen?
By the way, Napoleon, apparently, being in the stone building at the moment of the appearance of the "other sun", did not receive a strong dose of radiation. However, he died in the prison on the island of Saint Helen not from a natural death, but obviously from a male poisoning. Symptoms of radiation disease are very similar to such poisoning. [anon]