Also known as the Tunguska Event, the cause of this explosion in Russia remains a debate among scientists, though it's believed to be a meteorite or comet crash.
On June 30, 1908, a deafening explosion and a ball of bright light lit up the sky in Siberia near the Podkamennaya Tunguska River, which is now known as Krasnoyarsk Krai of Russia. The blast occurred at 7:14 a.m. local time and it sent seismic vibrations as far as 600 miles away. The Tunguska area is heavily forested and all trees in a 20-mile radius of the explosion site fell down and were scorched. The fallen trees were pointed away from a central spot which is a typical pattern caused by an explosion.
Eyewitness Reports of the Tunguska Event
The Tunguska Explosion was in a remote area that was populated by Evenki reindeer herders who were interviewed by scientists several years later. In a report prepared by William K. Hartmann for the Planetary Science Institute, eyewitnesses who were near the explosion and who were further away were interviewed. A person near the explosion reported the following: "Early in the morning when everyone was asleep in the tent, it was blown up in the air along with its occupants. Some lost consciousness. When they regained consciousness, they heard a great deal of noise and saw the forest burning around them, much of it devastated." In areas further away from the explosion site, it was reported that the sky looked like it was on fire. It was also described as a large glowing ball travelling across the sky. In all locations, eyewitnesses heard huge bang in the sky and then felt a shockwave. There were reports of a hot wind.
Theories of the Causes of the Tunguska Explosion
Scientists have put forth several theories as to the cause of the Tunguska Event and this is due to lack of evidence. No crater and no large meteorite fragments have been found. The only physical evidence was toppled and charred trees. Chemical analysis of soil and water showed higher content of specific minerals.
Was the Tunguska Explosion Caused by a Comet?
It has been theorized that a small comet composed of dust, ice and possibly with a stony coating, vaporized when it entered the earth’s atmosphere. This explains why there was no crater. The glow in the sky was caused from fragments of the comet remaining in the upper atmosphere. It was also coincidental that Comet Encke caused a meteor shower at the same time as the Tunguska Explosion. It was possible a fragment broke away from the comet.
Was the Tunguska Explosion Caused by an Asteroid?
Although there was no crater, there is a theory that an asteroid exploded and disintegrated before it hit the ground. Samples of the trees were examined and it contained significant levels of a material found in asteroids and not in comets. The damage to the trees was due to a thermal blast and explains why it covered a large area.
Other Theories About the Tunguska Explosion
- A natural gas explosion occurred under the crust of Earth.
- A large chunk of antimatter was annihilated in space and entered Earth’s atmosphere.
- A comet containing deuterium, also known as heavy hydrogen, had a nuclear reaction and exploded like a hydrogen bomb.
- A small black hole passed through Earth by entering at Tunguska and causing an explosion. It left by exiting in the North Atlantic.
- An alien spaceship exploded or an alien weapon was discharged.
Many theories as to the cause of the Tunguska Explosion can be partially explained and disproved. To this day, it still remains a mystery.
Reference:
http://www.psi.edu/epo/siberia/siberia.html