Dense clouds formed over the region at high altitudes which reflected sunlight from beyond the horizon.
The resulting seismic shockwave registered with sensitive barometers as far away as England. “he combination of pressure and heat caused the asteroid to fragment and annihilate itself, producing a fireball and releasing energy equivalent to about 185 Hiroshima bombs,” says NASA. The Tunguska meteor, however, was much bigger, and its explosion was likely much nearer to the surface. Like today’s Russian meteor, the Tunguska meteor was thought not to have hit the ground in a conventional impact, but rather to have exploded above the ground. Now known as the Tunguska event, an expedition to the area made in 1921, says the Guardian, “laid bare the devastation caused by impact, with 80m of trees levelled over 830 square miles (2,150 sq km).” The explosion sent out a shockwave that decimated the region. On June 30, 1908, says NASA, a truly massive meteor exploded near the Podkamennaya Tunguska River in Siberia. The meteor’s break-up released energy equivalent to a few hundred thousand tons of TNT. But while it was surely scary for those whose heads it passed over, compared to a disaster that took place a few thousand miles to the east more than 100 years ago, today’s meteor was rather puny. Photo: Vokrug Sveta / Wikimedia CommonsĮarly this morning in Russia, when a meteor broke up a few dozen kilometers above ground, its supersonic flight and mid-air death generated shock waves that rattled houses, broke windows, and sent dozens to the hospital. A comet – being less dense – would have to be slightly larger.Trees blown over by the shock wave of the 1908 Tunguska meteor. If it was an asteroid, it was probably about 36 m (120 ft) in size and 100,000 metric tons (220 million pounds) in weight. 110 years later, the matter still hasn’t been resolved. There are numerous other indications, too, which go in favour of one hypothesis and against the other. The glowing skies – suggesting high levels of water vapour in the atmosphere – are more likely to occur due to a comet, but some investigations of the resin of the impacted trees noted presence of material common in asteroids and rare in comets. Some argue that it was a small asteroid, others that it must have been a small comet (or a comet fragment). The two options, then, are what the object itself might have been. The blast area and other effects point to that conclusion, too.
Because no crater was ever found on the ground, and no meteorite either, it is thought that the object disintegrated (exploded) before reaching the surface. It is quite clear that an object from outer space entered the atmosphere over central Siberia. In the decades that followed, most scientists have agreed on two most likely explanations for what had occurred at Tunguska. The flattening of more than 80 million trees over 2150 square kilometres (830 square miles) in a radial pattern around the epicentre was indeed confirmed by the expeditions, which went out to explore the origin of this extraordinary event. A notable feature of nuclear explosions, but missing from the account above – because the eyewitness was too far to see it – is the razing to the ground of any buildings or trees near the epicentre, possibly combined with spreading of fires. More down-to-Earth commentators note that any large explosion will exhibit similar patterns. Indeed, this has led to some science-fiction theories about nuclear-powered alien spacecraft exploding over the Siberian skies. Anyone familiar with the details of the events in Japan in August 1945 might recognise this sequence as being extremely similar to the events close to ground zero of the nuclear explosions above Hiroshima and Nagasaki, except of course the Tunguska event – named after the nearby river called Stony Tunguska (‘Podkamennaya Tunguska’, literally ‘Tunguska under the stones’) – took place several decades earlier.
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