A 100-year mystery caused by an asteroid: the truth about the Tunguska explosion
Can you imagine what happens when an asteroid hits Earth? Maybe you think of the extinction of the dinosaurs, or the disaster in a Hollywood movie?
However, what you may not know is that just the last century, the Earth was hit by an asteroid, and this event has been a mystery to the scientific community, and its truth has only recently been revealed.
This was the Tunguska explosion that took place in 1908.
The Tunguska explosion was a huge explosion that occurred in the air near the Tunguska River in Siberia, Russia, at 7:17 a.m. on June 30, 1908.
The explosion was as powerful as 20 million tons of TNT, more than 1,000 times more than the atomic bombs that were later dropped on Hiroshima and Nagasaki.
The explosion destroyed 2,000 square kilometers of forest and toppled about 80 million trees.
The sound of the explosion traveled hundreds of kilometers and could even be heard elsewhere in Europe and Asia.
The explosion also produced strong seismic and barometric waves, as well as high temperatures and strong light.
For a few days after the explosion, night skies across the globe took on a dark red color, likely due to the dust and ice crystals from the explosion reflecting sunlight at high altitudes.
The explosion is considered one of the biggest natural disasters of the 20th century and one of the most mysterious.
The cause of the Tunguska explosion has always been a puzzle for the scientific community.
Since the explosion took place in an inaccessible area, and Russia was in turmoil at that time, there was no timely scientific investigation.
It was not until 1927 that the Soviet mineralogist Kulik led a scientific expedition to the site of the explosion.
What they found was a striking sight: thousands of square kilometers of trees had been burned or fallen in a radial pattern.
However, they did not find any traces of meteorites and did not find any craters.
This confused them a lot, as they believed that the explosion was caused by a meteorite hitting the Earth.
Over the next few decades, scientists came up with a variety of hypotheses in an attempt to explain the cause of the Tunguska explosion.
Some believe that a comet hit the Earth because the comet is mainly composed of ice and dust, so it completely evaporated at the time of impact, leaving no debris behind.
Some people believe that it is an antimatter, that is, substances that are the opposite of ordinary matter, and when they come into contact with ordinary matter, they annihilate each other, releasing a huge amount of energy.
Some even believe that it was caused by alien spaceships or human experiments.
These hypotheses all have some basis, but they also have some loopholes and are not widely recognized.
It is only recently that scientists have found a more convincing answer.
Using modern technology, they conducted a detailed analysis of the soil and trees at the site of the explosion and found some interesting clues.
They found that the soil contains some rare elements such as nickel, cobalt, iridium, etc., which are rare on Earth but are common in meteorites.
They also found that the tree's growth rings contained some radioactive isotopes, such as carbon-14 and nitrogen-15, and the content of these isotopes changed significantly before and after the explosion, indicating that the explosion produced intense radiation.
These discoveries all suggest that the cause of the explosion was indeed a meteorite hitting the Earth.
But why didn't the meteorite leave any traces? Scientists believe that this is because the meteorite had been broken down into many small pieces by the friction and pressure of the atmosphere before impact, and these small pieces exploded in the air, forming a huge fireball that released a huge amount of energy, but did not form a significant impact crater.
This phenomenon is known as the "water drift phenomenon" and is like a rock jumping on the surface of the water, with each jump producing a splash but not leaving a pit on the surface of the water.
Based on calculations, scientists estimate that the meteorite has a diameter of between 30 and 80 meters, a mass of between 10,000 and 20,000 tons, a speed of between 15 and 20 kilometers per second at the time of impact, and an altitude of between 5 and 10 kilometers at the time of the explosion.
The Tunguska explosion was a rare astronomical event and an astonishing natural phenomenon.
It reminds us that Earth is not a safe place and that it can be threatened by outer space at any time.
It also makes us lament that the development of science is a long process that requires continuous exploration and verification in order to uncover the mysteries of nature.
The truth of the Tunguska explosion, after more than a century of pursuit, has finally been given a reasonable explanation, but it is still a century-old mystery worthy of our deep thought and awe.