Most people have some knowledge of the giant meteor which hit the Earth some 66 million years ago and wiping out the dinosaurs as well as many other species. Researchers have discovered the impact zone in Central America and scientists have provided us with much information about its effect on the planet. But because it happened millions of years ago, we don’t have any first-hand evidence as to what an actual large meteor strike is like.
However, all that changed on 30th June 1908, in Russian Siberia.
Luckily for humankind, this meteor strike was nothing as large as the one which killed the dinosaurs, but it was big enough to give us clear evidence of what such an event is like. The impact was in a densely forested area close to the Tunguska river. It was very fortunate that very few people lived there.
However, about 40 miles to the north of the impact, we have an eye-witness account of the event. Sergei Semenov was about to eat breakfast. The time was 7-17am local and he said he saw something in the sky. I will let him tell his story in his own words.
“I suddenly saw directly to the north…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 in fire. At that moment I became so hot that I couldn’t bear it, as if my shirt was on fire; 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 and 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 that rocks would smash it. When the sky opened up, hot wind blew hot wind raced between the houses, like from cannons, which left traces in the ground like pathways, and it damaged some crops.”
The effects of the blast which was estimated to be at least 1,000 times that of the nuclear bomb dropped on Hiroshima in 1945, were felt as far away as the United Kingdom. It flattened up to 80 million trees over an area of 830 square miles. If this had occurred in the centre of London, then everything within the M25 would have been destroyed. As I said earlier, the Tunguska region is pretty devoid of human life and it was reported that it claimed the lives of only three people.
Strangely, it would be 13 years later before the site was investigated and a meteor impact was decided as the cause. There was no noticeable crater which indicated that the angle of strike was shallow. It was also thought that the swampy ground might have sucked up much of the debris. But this did not really answer all the questions posed by the impact.
Another theory was that it was not a meteor but a comet. These are mainly composed of ice, so that the debris field would not be as great. However, a further investigation did find material which matched what would be expected from an iron-type meteor.
The latest theory is that the area was grazed by an asteroid and that it “bounced” back into space. This would mean that there was no actual impact, but it would have produced shockwaves travelling at 12 miles per second on the surface. This would be at a height of only about 6 miles above the ground. Whatever, was the real reason, we can be thankful that NASA and other agencies try to map all such near-Earth objects in order to detect any possible future impacts.
But we can be pretty sure of one thing…there will be another large strike sometime in the future. Hope you all feel better now!
John Pullen 