The Tunguska Event: A Cosmic Mystery: The Scientific Investigations

The very, very short (video) version...

The very, very short (video) version...

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 This article is a part of a series:

• The Tunguska Event: A Cosmic Mystery: An Introduction
• The Tunguska Event: A Cosmic Mystery: The Eyewitness Accounts
• The Tunguska Event: A Cosmic Mystery: The Scientific Investigations
• The Tunguska Event: A Cosmic Mystery: The Alternative Theories
• The Tunguska Event: A Cosmic Mystery: The Cultural Impact
• The Tunguska Event: A Cosmic Mystery: The Modern Implications
• The Tunguska Event: A Cosmic Mystery: The Conclusion

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If you've been following this series, you know that the Tunguska event was a massive explosion that occurred in a remote area of Siberia in 1908, flattening millions of trees and creating a shockwave that was felt hundreds of kilometers away. But what caused it? And how do we know?

In this article, we'll explore the fascinating history of the scientific investigations that tried to unravel the mystery of the Tunguska event. We'll see how the first expeditions to the site found the evidence, what challenges and difficulties they faced, and what discoveries and conclusions they made.

The First Expeditions

The first person to investigate the Tunguska event was Leonid Kulik, a Russian mineralogist who worked at the St. Petersburg Museum of Mineralogy. He learned about the event from newspaper reports and eyewitness accounts, and became intrigued by the possibility that it was caused by a meteorite impact. He decided to organize an expedition to the site in 1921, hoping to find fragments of the meteorite and study its composition.

However, his expedition was not successful. He faced many obstacles, such as lack of funding, transportation, equipment, and local guides. He also had to deal with political instability, civil war, and bandits. He reached the town of Vanavara, about 65 km from the epicenter of the blast, but could not go any further due to the swampy terrain and the onset of winter. He returned to St. Petersburg empty-handed, but determined to try again.

He managed to secure more funding and support for his second expedition in 1927. This time, he hired local reindeer herders to guide him and carry his supplies. He also brought a camera, a compass, a barometer, and a seismograph. He reached the epicenter of the blast on May 30, 1927, and was stunned by what he saw.

He described it as "a sea of fire" that stretched for tens of kilometers. He saw millions of fallen trees lying radially from the center, pointing away from the blast. He also saw a few standing trees that were charred and stripped of their branches and bark. He estimated that the area of devastation was about 2,150 square kilometers.

He searched for traces of the meteorite, but found none. He dug several pits and trenches, but only found soil and rocks. He concluded that the meteorite must have exploded in mid-air before reaching the ground, vaporizing itself and creating a powerful shockwave. He also speculated that it was made of ice or some other fragile material that could not survive the atmospheric entry.

He collected samples of soil, rocks, and wood from the site and brought them back to his laboratory for analysis. He found traces of magnetite and silicate in some of them, which he interpreted as evidence of meteoritic origin. However, later studies showed that these minerals were common in the region and not related to the event.

He published his findings in several papers and books, and became widely known as the "father of meteoritics". He also advocated for the establishment of a permanent research station at the site, which was eventually built in 1958 and named after him.

The Later Expeditions

Kulik's expeditions sparked more interest and curiosity among other scientists and explorers who wanted to study the Tunguska event. Over the years, dozens of expeditions were conducted by various teams from different countries and disciplines. They used more advanced methods and technologies, such as aerial photography, geophysical surveys, chemical analysis, radiocarbon dating, computer modeling, and satellite imagery.

Some of their main findings were:

• The blast released an energy equivalent to about 10-15 megatons of TNT, or about 1,000 times more than the atomic bomb dropped on Hiroshima.
• The blast occurred at an altitude of about 5-10 km above the ground.
• The blast created a fireball that was visible for hundreds of kilometers around.
• The blast generated a mushroom cloud that rose up to 50 km in height.
• The blast produced a sound that was heard as far as 1,500 km away.
• The blast caused an atmospheric pressure wave that circled the Earth several times;
• The blast triggered seismic waves that were recorded by instruments around the world.
• The blast affected the Earth's magnetic field and ionosphere.
• The blast may have influenced the weather and climate for several years after.

However, some questions remained unanswered:

• What was the nature and composition of the object that caused the blast?
• What was its size, mass, speed, trajectory, and origin?
• Why did it explode in mid-air instead of hitting the ground?
• Did it leave any remnants or debris behind?
• How did it affect the environment and ecology of the region?
• How did it affect the health and genetics of the local people and animals?

The Alternative Theories

The most widely accepted explanation for the Tunguska event is that it was caused by a comet or an asteroid that entered the Earth's atmosphere and exploded in mid-air. However, not everyone agrees with this hypothesis. Over the years, many alternative theories have been proposed, some more plausible than others. Some of them are:

• A nuclear explosion caused by a natural or artificial device.
• A collision between the Earth and a fragment of a planet or a moon.
• A volcanic eruption or a gas explosion from the ground.
• A lightning strike or a ball lightning phenomenon.
• A plasma discharge or a beam of energy from the Sun or another source.
• A visit or a crash of an alien spacecraft or a weapon.

Some of these theories are based on scientific evidence and arguments, while others are based on speculation and imagination. Some of them have been tested and refuted, while others remain unproven and controversial. Some of them have gained popularity and support, while others have been dismissed and forgotten.

The Tunguska event is one of the most intriguing and mysterious events in history. It has inspired and challenged scientists, explorers, writers, artists, and enthusiasts for more than a century. It has also raised awareness and concern about the potential dangers and opportunities of cosmic events for humanity and the planet.

However, despite all the efforts and discoveries, the Tunguska event remains a cosmic mystery. We may never know for sure what happened on that fateful day in 1908, or why it happened. We can only hope that we are prepared for whatever may happen next.