On June 30, 1908 something exploded over Siberia with a force never before seen on earth, and perhaps, not since. Witnesses to the event said they say a pinpoint of light in the night sky get larger over a ten minute period before it exploded with such force a train conductor thought his train had been derailed from 800 miles away from the center of the explosion! The closest village of Nizhne-Karelinsk had roof damage on many homes and it was 200 miles away.
Whatever had exploded over Siberia had a shock wave that traversed the world twice. The weather on planet Earth was affected for the next year and Earth inhabitants were treated to glorious light shows at night. It was reported that you could even read the London Times at midnight without a lamp. Not since Krakatoa had the world seen anything such as this.
What is not commonly known, is that people of the world really did not know what the cause of this was. Russia was a very closed society and news of this explosion was not leaking out. It was not until the revolution that the full details emerged. In 1921 Russian scientist were doing work on meteorites and discovered the documents that they did not even know existed.
The photo on this post shows that the trees all fell in the same direction indicating a massive explosion. Many have speculated that this was an atomic bomb or a UFO and such.
MY TAKE: It could not have been a comet. They move way to slow. A meteor is more likely or a runaway asteroid. Events in the twentieth century have witnessed the impact on Jupiter of very large space debris proving that Earth could be vulnerable to such a thing.
No UFOs or secret atomic bombs would be needed. Our existence is very precarious.