Tunguska+event

=Introduction= Tunguska event is still one of unsolved mysteries on Earth. Still everyone accepts that it was a gigantic explosion. It is estimated that the explosion was roughly equal to United State's Castle Bravo nuclear bomb (1000x more powerful than the one dropped in Hiroshima and one-third of the Tsar Bomba, the most powerful nuclear weapon ever detonated). Event caused a shock wave estimated at 5.0 on the Richter scale that was able to broke windows hundreds of kilometers from the hypocenter of explosion. The explosion created a loss of around 80 million trees.

=Characteristics= // "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 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." //
 * // -S.Semenov, eyewitness //**

Tunguska event had few characteristics that made it special: Sources: Wikipedia, TIEDE-magazines
 * ====**Meteoroid airburst**====
 * This is based on the leading scientific theory what Tunguska event was.
 * A meteoroid entered Earth's atmosphere with speed of around 34 760 km/h and exploded mid-air 6-10 kilometers from the ground creating a massive burst of particles.
 * According to knowledge that mankind has gathered since the half of 20th century, we know that this kind of airbursts occur rather frequently. A stone particle with a radius of 10 meters can cause an explosion of 20 kilotons (similar to Fat Man dropped in Nagasaki).
 * ====**Blast patterns**====
 * Effects of Tunguska event were successfully replicated in Soviet experiments mid-1960s. Simulating forest with matches and explosion with a small charge scientist were able to create butterfly shaped blast patterns that where found unbelievable similar to blast patterns of Tunguska event. Near existing Lake Cheko is rumored to be one crater of a particle from the explosion.[[image:Tunguska_epicenter.jpg align="right" caption="Hypocenter of Tunguska event in 2008. Area is mainly occupied with swamps."]]
 * ====**What it really was?**====
 * There are many theories of what Tunguska event really was, because there isn't a single water-proof theory. (The meteoroid airburst one is the most likely to be true.)
 * **An asteroid or a comet?**
 * This is the debate. It started in 1930 when British astronomer F.J.W Whipple suggested that it was a small comet. This hypothesis gained support due to "glowing skies" phenomenon. It was afterwards criticized that composition of a comet would not be able to travel through the outer layers of atmosphere without disintegrating earlier than it had. Asteroid theory got boosted when Italian scientist claimed in 2001 that according to their studies the particle in question may have its origin in the asteroid belt.
 * **Comet 2005NB56**
 * One study suggests: "A chunk of comet 2005NB56 caused 5-10 megaton fireball, bouncing off the atmosphere and back into orbit around the sun." The comet 2005NB56 is estimated to pass close to Earth again in 2045.
 * **Natural H-bomb**
 * Deuterium in a comet entering Earth's atmosphere may have undergone nuclear fusion reaction.
 * **Black hole**
 * A small black hole passing through the Earth was the reason. Logically can be proven false, because exit event should have happened in the North Atlantic.
 * **Antimatter**
 * A chunk of antimatter falling from the space was the reason. Doesn't have an answer for mineral debris.
 * **The Wardenclyffe Tower**
 * Tunguska event was a result of Nikola Tesla's experiments using the Wardenclyffe Tower.
 * **Alien spaceship crash**
 * This theory started from a science fiction story "The Explosion" written by Alexander Kazantsev in 1946 claiming that a Martian nuclear-powered spaceship tried to land on Earth, but experienced fateful problems. Yuri Labvin, the president of the Tunguska Spatial Phenomenon Foundation, is a keen supporter of this theory.
 * **Geophysical hypothesis**
 * This theory suggests that there was no particle coming towards the ground but a sudden release and subsequent explosion of 10 million tons of natural gas from the Earth's crust.

Written by Tyko