On June 30, 1908, an aerial explosion of a power similar to that of a thermonuclear weapon downed trees in an area of 2,150 square kilometers. The event took place in the vicinity of the Podkamennaya River, in Tunguska (Russia), and some thirty hypotheses have been developed to explain it. But what really happened in Tunguska?
Humanity, or at least modern man, had had few opportunities to attend events of this kind. In fact, nuclear bombs were still several decades away from producing such devastating effects as those that took place in June 1908. With the exception of a few volcanic eruptions or major earthquakes, no phenomenon had been capable of knocking down more than 400 people standing on their feet. miles from the scene. This explains the fascination that the so-called “Tunguska Event” has for most people, and why there are so many hypotheses to try to explain what happened that summer.
On June 30, 1908, an explosion occurred that was detected by numerous seismic graphic stations around the world. Its magnitude was such that it could even be recorded by a barometer from a UK meteorological office, located thousands of kilometers away, thanks to fluctuations it caused in atmospheric pressure. Much less subtle, the effects in the vicinity of the “zero point” included the felling of all trees located in an area of more than 2,000 square kilometers.
In towns located 400 kilometers from the epicenter of the explosion, the blast wave was powerful enough to break windows and knock down adults. 600 kilometers from the impact, in the Kansk district, villagers say that some sailors and horses were knocked over by the shock wave, while houses shook and dishes broke. Even the conductor of the famous Trans-Siberian train had to stop the march because he feared that the vibrations would derail the convoy.
Some witnesses reported that during the weeks following the event, the nights were so bright that in various places in Russia and Europe it was possible to read after sunset without the need for lamps or candles. You can imagine what that would have meant in a time when almost no one had seen a car or an airplane, where life was simple and predictable, in a world that did not know television and radio was just being born.
Records show that even in the United States several astronomical observatories, including those at Mount Wilson and the Smithsonian, found a significant decrease in atmospheric transparency that lasted for several months. This effect, the result of the amount of dust that was thrown into the atmosphere, would be associated years later with nuclear bombs, and would be called “nuclear winter”, given the potential capacity of such an explosion to engulf the planet. in a long and dark “winter” fruit of the darkening of the atmosphere.
In fact, experts calculate that the Tunguska Event released the energy equivalent to an atomic bomb of 10 to 15 megatons, where one megaton is equivalent to the explosion of a million tons of TNT. To give you an idea of what this means, let’s remember that the one thrown on Hiroshima had “only” 0.015 megatons, and it devastated an entire city.
Fortunately, Siberia was a very sparsely populated area. In many regions even today you can travel hundreds of kilometers without finding even traces of humanity. If the Tunguska Event had taken place over a densely inhabited area, such as Europe or America, the deaths would have been numbered in the millions. Most of the witnesses to the 1908 explosion belonged to the Tungus people, a nomadic tribe of Mongol origin that survived in the cold steppes thanks to reindeer herding. These people said that they saw an object fall that “shone like the sun.” It must not have been easy for them to fall asleep that night!
Obviously, such an event has generated hypotheses of all kinds. First of all, if you use Google to find information you will see how thousands of sites dedicated to UFOs, conspiracy theories or the supernatural speculate with the possible accident of an alien mothership, the detonation of a secret nuclear device (decades before it was invented “officially”), time machines that explode when traveling to the past, antimatter, natural atomic bombs or practically any nonsense you can think of.
However, the scientific community, based on the evidence collected, the testimonies of witnesses and computerized models, agrees that it was a small comet that caused the Tunguska Event. Composed basically of ice and dust, a comet (or perhaps, a “piece of a comet”) exploded without touching the ground, being completely vaporized by the heat generated by the friction with the Earth’s atmosphere. The models show that all the ice contained in the comet can be sublimated, turning directly into gas, which when dispersed in the atmosphere would eliminate all traces of the explosion.
The trees would have been knocked down mainly by the atmospheric shock wave and, to a lesser extent, by the thermal wave. Some think that it is highly unlikely that a comet would have gone unnoticed in the days (and nights) leading up to the event, but the trajectory of the fall suggests that the one responsible for the explosion would have come from a direction almost coincident with the Sun, which would have done very difficult for astronomers to detect. Especially if it was small or had exhausted the volatile substances responsible for generating the showy tails characteristic of these bodies.