The Tunguska event is the largest impact event on Earth in recorded history.
On 30 June 1908, an explosion ripped through the air above a remote forest in Siberia, near the Podkamennaya Tunguska river.
As witnesses said,” A fireball streaked across the daytime sky.”
The fireball is believed to have been 50-100m wide. It depleted 2,000 sq km of the taiga forest in the area, flattening about 80 million trees.
It took only moments to explode in the atmosphere just above Siberia’s Podkamennaya Tunguska River, what is the present day Krasnoyarsk Krai of Russia.
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 to have hit the surface of the Earth.
This armageddon-like event made the earth shiver. Windows shattered in the closest town, some 35 miles away from ground zero. According to the inhabitants of the town, they could feel the heat of the blast and many had also been blown off their feet.
It is estimated that the Tunguska explosion knocked down some 80 million trees over an area of 2,150 sq km (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 human fatalities were officially documented.
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 30 October 1961 (which, at 50 Mt, is the largest nuclear weapon ever detonated).
A scientific expedition to the remote region did not take place for well over a decade. In 1921, it would be Leonid Kulik, a curator of the St. Petersburg Museum who worked with meteorite collections, who attempted conducting the first expedition on the site. Initially, his team could not find out what really happened as they never reached the area due to the severe weather conditions of the Siberian outback.
Kulik was finally able to lead a scientific expedition to the Tunguska blast site in 1927. He hired local Evenki hunters to guide them to the center of the blast area, where they expected to find an impact crater. To their surprise, there was no crater to be found at ground zero. Instead they found a zone, roughly 8 kilometers (5.0 miles) across, where the trees were scorched and devoid of branches, but still standing upright.
It puzzled him that there was no impact crater, or in fact, any meteoric remnants at all. To explain this, he suggested that the swampy ground was too soft to preserve whatever hit it and that any debris from the collision had been buried.
Russian researchers later said that it was a comet, not a meteor that caused the damage. Comets are largely made up of ice – not rock, like meteorites – so the absence of alien rock fragments would make more sense this way. The ice would have started to evaporate as it entered Earth’s atmosphere, and continue to do so as it hit the ground.
Another proposal was that a nuclear explosion caused the blast. An even more outlandish suggestion was that an alien spaceship crashed at the site on its search for the fresh water of Lake Baikal.
“Some suggested the Tunguska event could have been the result of matter and antimatter colliding.”
Regardless of the absence of details, scientists have managed to reach a sort of consensus: any remnants from the stellar body that penetrated into Earth’s atmosphere disintegrated to dust within the turbulent collision process. This probably happened 10 miles above the ground, maybe little less or more than that. The collision of the object with the atmosphere of our planet had been so engaging that it instantly resulted in intense heat and shockwaves, all felt miles away from the impact point. Airburst subsequently dispersed on the ground, which is when the trees in the area ended up flattened.