Podkamennaya Tunguska is a tributary or a stream for the river Yenisey located in the Yeniseysk Governorate( present day Krasnoyarsk Krai). On the 30th June 1908 a huge explosion occurred next to the river, Which is known to be the Tunguska Event or the largest meteorite explosion happened in the modern history.
There are limited resources of to clarify whether the explosion was happened due to a meteorite or not. But there are eye witnesses that confirmed the theory of the meteorite. The region was not very populated at the time. Therefore few eye witnesses reports and few news paper articles are the only sources of written evidence of the event. Following are the best description of what happened at the blast that describes it the best.
“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. 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”
” We heard whistling and felt strong wind. We were in the hut, couldn’t see what was going on outside. Suddenly, I got shoved again, this time so hard I fell into the fire. There was noise beyond the hut, we could hear trees falling down. Then the thunder struck. This was the first thunder. The Earth began to move and rock, the wind hit our hut and knocked it over. My body was pushed down by sticks, but my head was in the clear. Then I saw a wonder: trees were falling, the branches were on fire, it became mighty bright, how can I say this, as if there was a second sun. It was like what the Russians call lightning. And immediately there was a loud thunderclap. This was the second thunder. The morning was sunny, there were no clouds, our Sun was shining brightly as usual, and suddenly there came a second one! I had some difficulty getting out from under the remains of our hut. Then we saw that above, but in a different place, there was another flash, and loud thunder came. This was the third thunder strike. Wind came again, knocked us off our feet, struck the fallen trees. We looked at the fallen trees, watched the tree tops get snapped off, watched the fires. I looked there and saw another flash, and it made another thunder. But the noise was less than before. This was the fourth strike, like normal thunder. Now I remember well there was also one more thunder strike, but it was small, and somewhere far away, where the Sun goes to sleep.”
Is It Really True?
If you read the description then you might wonder ‘Is is possible?’ The villagers did not lie about what they witnessed because after the impact the place was nothing like before. Although there was no crater was formed, after the impact it had flattened the area of 2150 km2 forest. The explosion was even registered at seismic stations across Eurasia. The air waves from the blast were detected in Germany, Denmark, Croatia, and the United Kingdom, and as far away as Batavia, Dutch East Indies, and Washington, D.C.
In 1960 expedition the flattened forest area was confirmed as 2150km2. The shape of the area looked like a gigantic spread-eagled butterfly with a “wingspan” of 70 km (43 mi) and a “body length” of 55 km (34 mi).
The energy of the impact was estimated to be about 10-30 megatons of TNT or 42-130 *1015 J. The difference is huge because scientists were unable to calculate the exact height of the burst point. In more recent calculations shows that the energy of the object was focused downwards compared to a nuclear explosion. The bomb dropped on Hiroshima was equal to 15 kilotons of TNT, which means the power of this impact is 1000 times powerful that the Hiroshima bomb. But a paper published in 2019 suggested that the explosive power could be 20-30 megatons of TNT.
The shock wave of the blast is estimated to be 5.0 on the Richter Magnitude Scale. Which is fully capable of destroying a large metropolitan area. Fortunately the area was not populated therefore the damage to the human life is minimum. But sadly it was not same to the wildlife in the area. The amount of life damaged was not quantified. But over 80 million trees were damaged due to the explosion.
Is it a Meteorite?
In 1930 F. J. W. Whipple, a British astronomer suggested that the Tunguska body could be a small comet. A comet is composed of dust and volatiles, such as water ice and frozen gases, and could have been completely vaporised by the impact with Earth’s atmosphere, leaving no obvious traces. The comet hypothesis was further supported by the glowing skies (or “skyglows” or “bright nights”) observed across Eurasia for several evenings after the impact, which are possibly explained by dust and ice that had been dispersed from the comet’s tail across the upper atmosphere. The cometary hypothesis gained a general acceptance among Soviet Tunguska investigators by the 1960s.
After Effects of the Impact
The sky in Europe and Asia was brighter for several days after the impact. There are reports of brightly lit photographs being successfully taken at midnight (without the aid of flashbulbs) in Sweden and Scotland. It has been theorized that this sustained glowing effect was due to light passing through high-altitude ice particles that had formed at extremely low temperatures as a result of the explosion After years the same phenomenon was occurred due to space shuttles.
Investigation of the Tunguska
The explosion was happened in 1908 but there was no investigation done at the time. the scientists and historians suggest that this was because of the political changes happened during that era. Also the area where the explosion was happened is very remote therefore not many attention was given and the explosion might have been a secret to outer countries.
The first expedition to the impact area was done in 1927 by the Russian mineralogist Leonid Kulik. He hired local hunters known as Evenki as guides. He and his group was expecting to find a crater created due to the meteorite but to his surprise there was no crater. Instead he found a area which had many trees laid flat while some trees were standing yet without the branches. By observing the pattern of the knocked down trees Kulik identified a radial pattern. After his first expedition Kulik persuaded the government to fund more expeditions in future. After that Kilik led three more expeditions to that area.
During these expeditions Kulik found several dozens of little “pothole” bogs, each 10 to 50 metres (33 to 164 feet) in diameter, that he thought might be meteoric craters. He believed them to be meteoric craters. After draining one of these holes he found an old tree stump so he ruled out the possibility of these being meteoric craters. In 1938 Kulik arranged an aerial photographic survey of the area which was about 250 km2. There were 1500 negatives (18*18 cm) but the negatives were destroyed in 1975 as part of an initiative to dispose of flammable nitrate film. The prints of the negatives are preserved for further study.
June 30th is named as International Asteroid Day, the anniversary of the Tunguska explosion. Asteroid Day aims to raise awareness about asteroids and what can be done to protect the Earth, its families, communities, and future generations from a catastrophic event.
Until today there are only assumptions and suggestions are presented for the explosions in Tunguska. The only reliable source to connect this explosion to a meteorite or a comet is the eye witnesses reports. No residue or meteorite pieces were found in the area. Scientists are trying to understand the physics and chemistry of this explosions up to date, which can be used to estimate future similar incidents. Which we all hope would not happen ever.