Originally posted by mathman
There was a tremendous blast with no debris. An asteroid would have left something, so it was most likely a large meteor or meteorite.
The Tunguska Explosion was most likely caused by an asteroid or meteoroid entering Earth's atmosphere and exploding in the air due to the extreme heat and pressure created by friction with the air. This theory is supported by the lack of evidence for a crater or impact site on the ground.
There is no evidence to suggest that the Tunguska Explosion was a nuclear event. The explosion occurred in 1908, before the development and use of nuclear weapons. The explosion also lacked the characteristic radioactive fallout associated with nuclear events.
The Tunguska Explosion is estimated to have had a blast equivalent to 10-15 megatons of TNT, making it one of the most powerful explosions in recorded history. It was about 1,000 times more powerful than the atomic bomb dropped on Hiroshima in 1945.
The Tunguska Explosion occurred in a remote, sparsely populated area of Siberia, so there were no direct witnesses to the event. However, there are reports of people in nearby towns seeing a bright light in the sky and feeling a shockwave, which is consistent with the explosion.
It is possible for similar events to occur in the future, as Earth is constantly bombarded by small asteroids and meteoroids. However, the chances of a similar event happening in the same location as the Tunguska Explosion are very low. Scientists are actively monitoring and tracking near-Earth objects to better understand and potentially prevent future impacts.