The year was 1908. Sitting on the front porch at the Vanavara trading post in Siberia was a man, taking it all in, a little after 7 in the morning. A few minutes later, however, he would be thrown off his chair and feel intense heat like never before. The reason for this was the Tunguska event. And this man was nearly 65 km from ground zero.
At about 7.15 a.m. on June 30, 1908, a powerful explosion occurred above a remote forest in Siberia, near the Podkamennaya Tunguska river. Thousands of people in a radius of over 1,000 km were able to witness this event and hundreds of accounts were collected in the aftermath.
Felt far and wide
A fireball the size of the sun, or even larger, a number of explosions accompanied by rip-roaring sounds and trembling Earth were all part of the reports. Seismic and atmospheric waves were recorded in various stations in Europe, including as far away as the U.K. Strange phenomena were observed in the night skies above Russia and much of Europe in the following days, from colourful sunsets to bright midnights.
The Tunguska event depleted 2,000 sq.km. of the forest area, shooting down 80 million trees, as they were flattened, lying in a radial pattern. Hundreds of reindeer also died, and other fauna must have also been surely affected. Miraculously, however, there were no human casualties officially reported.
Kulik investigates
Whereas some newspapers reported a supposed meteorite impact, others also speculated about a volcanic eruption, as the after-effects observed in the night were similar to those that followed the 1883 Krakatoa eruption. The inaccessibility of the region, along with the political climate in Russia (what with World War I and the Russian Revolution just around the corner), meant that scientific explorations to investigate the region didn’t materialise immediately.
It was only in 1927 that Russian mineralogist Leonid Kulik finally made a trip to the area. Taking interest in the region after having read some newspaper reports, Kulik first led an expedition in 1921 that failed owing to the harsh conditions. When he did reach the place, almost 20 years after the event took place, the damage was still there to be seen.
Apart from the large area of flattened trees, Kulik and his team found trees like telephone poles at ground zero – upright, but bereft of their limbs and bark. This kind of debranching occurs when fast moving shock waves break the tree’s branches, much before the branches have had their chance to transfer the impact momentum to the tree’s stem.
Power of 185 atomic bombs
Such debranched trees were also found at the site of another massive explosion that took place 37 years after the Tunguska event – Hiroshima, Japan. The Tunguska event, in fact, produced the energy equivalent of about 185 Hiroshima atomic bombs, making it the most powerful recorded in our history.
Kulik’s expeditions – he travelled to the Tunguska on three occasions – helped him explore the entire area and also collect eyewitness accounts from hundreds of locals, including the man who was at the trading post in Vanavara. What he didn’t find, however, were impact craters. Kulik and his team neither found a large crater, nor any meteoric materials as remnants at the site.
A number of theories
Kulik proposed that a meteor had exploded in the atmosphere, causing the observed fireball and the devastation that followed. The lack of hard data to expose the identity of the explosion meant that a number of alternate theories followed.
Comets were suggested instead of meteors to explain the absence of remnants as comets are made of ice and dirt, as opposed to rocks in meteorites. Nuclear explosions of extraterrestrial origin, a small black hole colliding with the Earth, matter and antimatter colliding with each other were some of the more outlandish explanations that were made. Verneshots – a hypothetical magma-gas mix that erupts violently from underground and is named after French author Jules Verne of “Journey to the Center of the Earth”-fame – have also been proposed in recent times.
Research continues
The most favourable explanation for the Tunguska event remains a large cosmic body, like a meteor or a comet, colliding with the Earth’s atmosphere. But as long as there is no conclusive evidence, researchers will continue to provide more theories, however strange.
