It is widely accepted that the Tunguska explosion was caused by a meteorite. Credit: Pixabay

Tunguska – UFO Crash or Natural Explanation? Here’s What the CIA Files Say

The latest collection of declassified CIA files includes a curious document on the Tunguska explosion.


Early in the morning of June 30, 1908, at 7 hours and 15 minutes local time, a fireball passed through the sky, observed by many residents of Eastern Siberia.

The flight of this unusual celestial body was accompanied by a sound resembling thunder. The ensuing explosion shook the earth, which was felt in a perimeter of more than a million square kilometers.


Initial studies on the Tunguska phenomenon began much later in the 1920s, when four expeditions organized by the USSR Academy of Sciences, were sent to the scene. Soon it was established that around the fall of the Tunguska meteorite, the trees had fallen from the center outwards, and in the middle, some of them stood but without a single branch.

Much of the forest was burned. Subsequent expeditions (about 20 in number) noticed that in the area of ​​the fallen forests, a specific figure in the shape of a “butterfly” was formed, whose axis of symmetry coincided with the trajectory of the meteorite (according to eyewitnesses): from east-southeast to the west-northwest.

The total area of destroyed forest was about 2200 square kilometers. It was found that the explosion did not occur when the meteorite came into contact with the Earth, but in the air at an altitude of 5-10 km. Many geophysical stations in Europe, Asia, and the Americas recorded airwaves orbiting the globe, and some seismic stations recorded earthquakes.

An old image from 1927 showing the fallen trees in the area of the Tunguska explosion. Credit: Wikimedia Commons
An old image from 1927 showing the fallen trees in the area of the Tunguska explosion. Credit: Wikimedia Commons

The blast completely burned the taiga and the rare huts within a radius of 5 to 7 kilometers, and the perimeter in which the trees were cut down varied from 25 to 30 kilometers. The dazzling orange glow was even seen in Western Europe.

As a result of the powerful explosion and the flow of hot gases, a wild forest fire broke out. A few minutes after the explosion, a magnetic storm broke out, registered in Irkutsk, which lasted 4 hours and looked strikingly like the geomagnetic disturbances observed after the explosion of nuclear facilities in the upper layers.

It is also interesting that from the Yenisei to the Atlantic coast of Europe, the night sky was so bright that it could be easily read without additional lighting. And this refers to the following night! In California, there was a sharp decline in the transparency of the atmosphere in July-August 1908.

But what caused this massive explosion? More than 110 years later, we do not have a definitive answer. More and more new theories about Tunguska come out every year, from comets to nuclear tests to UFOs, but without results.

Research continues to this day

The assessment of the energy force of the explosion showed higher values ​​of the energy released than during the fall of the Arizona meteorite, which formed a crater with a size of 1200 meters in diameter. However, there is no crater at the site of the Tunguska meteorite crash.

This is explained by the fact that the explosion occurred before the collision of the celestial body with the earth’s surface. Although research on the mechanism of the Tunguska meteorite’s explosion has not yet been completed, most scientists believe that this body, which has enormous kinetic energy, had low density (less than water density), low hardness, and high volatility.

A photograph from a 1929 expedition again showing the destruction caused by the Tunguska explosion. Credit: Wikimedia Commons
A photograph from a 1929 expedition again showing the destruction caused by the Tunguska explosion. Credit: Wikimedia Commons

They believe that this is what contributed to its rapid destruction and evaporation when it crashed into the denser layers of the Earth’s atmosphere. It appears to have been a comet consisting of frozen water and gases.

The “comet” hypothesis for the Tunguska meteorite was proposed by Russian researchers, based on modern data on the nature of comets. According to their estimates, the mass of the Tunguska meteorite was not less than one million tons, and the speed – 30-40 km/sec. The power of the explosion was about the same as that of a thousand atomic bombs, like the one dropped on Hiroshima.

In the area of ​​the crash, microscopic silicate and magnetic bubbles, resembling meteorite dust and representing the comet’s scattered nucleus, were found in the soil. It is possible that the cosmic dust from the comet’s tail was the cause of the special refraction of sunlight, which led to the night glow.

Most common theories about the Tunguska Event

Here is an illustration in support of the hypothesis that the explosion was caused by a meteorite. Credit:
Here is an illustration in support of the hypothesis that the explosion was caused by a meteorite. Credit:

The Tunguska meteorite, or as it is known in scientific circles as the “Tunguska explosion”, has not yet been fully studied. Many more studies are needed, but still, there are some hypotheses that await confirmation after more detailed research. Here are some of the basic assumptions:

• Hypothesis 1: The Tunguska meteorite was a comet. This is a hypothesis supported by most researchers. Many of the facts speak in its favor, but so far there is no complete confirmation of this assumption.

• Hypothesis 2: The Tunguska meteorite was composed of “anti-matter”. The explosion observed during its fall was the result of the interaction of “matter” with “antimatter”, which is accompanied by the release of a huge amount of energy, ie. nuclear explosion.

So far, this assumption has not been proven, although increased radiation has been observed in some areas of Tunguska. However, there are no radioactive elements in the upper layers, and such elements should be present if a nuclear explosion has indeed occurred there.

• Hypothesis 3: The Tunguska meteorite was a microscopic black hole that penetrated the Tunguska taiga, penetrated it, and exited the Atlantic Ocean. The phenomena that would occur in such an event (a separate issue is the possibility of the existence of black holes with a small mass) – the blue glow, the elongated shape of the destroyed forests, the absence of mass loss, etc. – do not fully correspond to the facts observed in the fall of the meteorite.

• Hypothesis 4: The Tunguska meteorite was a UFO flying over the Earth, but as a result of an accident, it fell into a sparsely populated area, such as the Siberian taiga, and before colliding with the earth’s surface, it self-destructed.

There are, of course, many other assumptions about the nature of this phenomenon, but scientists still can not find enough facts to support this or that theory. Since most “regular” theories have been spoken about millions of times already, why not focus on the most “impossible” assumption – that the Tunguska event was caused by UFOs?

Was the Tunguska explosion caused by a UFO?

Artistic impression based on old eyewitness reports. These reports, however, do not evidence that the explosion was caused by a meteorite. Credit: Don Davis
Artistic impression based on old eyewitness reports. These reports, however, do not evidence that the explosion was caused by a meteorite. Credit: Don Davis

Before we continue, I need to explain that we are not claiming that the Tunguska explosion was caused by a UFO, neither are we declining this hypothesis. We are here to discuss popular theories that point towards aliens or alien spacecraft and see where this leads us.

Now, with that said, here are several versions that claim a UFO was behind the Tunguska incident. I already described the most popular version of a UFO crashing in situ by accident or not. But there are other more entertaining assumptions.


Various experts from different fields have expressed their thoughts and some suggest this version: a UFO (alien spaceship) was attempting a take-off and crashed. This sounds like a different approach to the main UFO theory so here’s a better one.

There is an official Public-State Fund in Siberia called the “Tunguska Space Phenomenon”. About 16 years ago, the president of this organization came out with his own version. He suggested that an alien civilization located in the Siberian taiga protected us from destruction by blasting out the meteorite. According to him, a UFO deliberately crashed with the Tunguska meteorite to protect us.

Here is a fourth theory, suggested by one of the first researchers to conduct an expedition 100 years ago. He claimed that the Tunguska event was aliens dropping knowledge on us. The problem is that humanity is not ready for this knowledge and it would only be revealed to us when we reach the necessary state of advancement.

Of course, no theory likely comes close to the real truth. The problem is that we may never learn what truly happened. After all, not a single piece of debris or remains was ever discovered by any of the 50+ expeditions.

The fact that there are no remains, however, does not mean that there were any UFOs or aliens either. Recently, I stumbled upon a declassified CIA document on Tunguska that provided some insight on the CIA’s opinion on the UFO theories. Here is what the American intelligence had to say about the explosion.

Declassified CIA Document Suggests Tunguska Explosion Was UFO

Tunguska site as seen on Google Earth. Credit: Google
Tunguska site as seen on Google Earth. Credit: Google

A few weeks ago, the CIA declassified several thousand old documents, once again, thanks to the efforts of the Black Vault. You can see the entire new collection of files here.

One particular document caught my attention as it discussed the possibility that the Tunguska event was in fact caused by UFOs. Before this collection of documents, I guess nobody had known that the CIA had made their own investigation decades ago.

Anyhow, the two pages describe one particular research on the Tunguska event from the 1960s by the Soviet Union. It addresses the “history” of UFO sightings but emphasizes the Tunguska explosion as the most remarkable UFO phenomenon in history.

The focal point of this declassified document are a couple of sentences that describe the flight of the Tunguska meteorite. Based on the analysis of observations from all around the Soviet territory and additional research, it is believed that the Tunguska object carried out a maneuver as it was falling down from the sky.

The CIA file continues with the authors’ opinion that if the government confirms that the Tunguska explosion was a UFO, it would pose a variety of new major problems worldwide. The author expresses his worries that if the existence of aliens is confirmed, it would bring chaos and calamity.

The document ends with a call to action that all claims about UFOs connected to the Tunguska explosion should be discarded and forgotten. According to the author, research should be strictly scientific and there is no place for anything extraordinary.

All in all, the declassified CIA document does not confirm that it was a UFO but it does not discard this option. Unfortunately, it was never officially confirmed that the Tunguska meteorite carried out a maneuver but based on this document, it is clear that somebody in the CIA believed in this version. You can read the entire document here.

In the end, will we ever learn the truth? If the CIA or any other intelligence found out something more, it is clearly being hidden. But what did they find when there were no remains? Furthermore, the Tunguska explosion happened long before the advanced technology of today. All researchers have to work with are the eye-witness reports from 100 years ago and 2200 square kilometers of destroyed forests.

The Tunguska explosion was just one of the many extraordinary phenomena that occurred in 1908 but these other events are a subject for another time. Will experts ever find an answer? I personally doubt it.

Join the discussion and participate in awesome giveaways in our mobile Telegram group. Join Curiosmos on Telegram Today.


Atkinson, N. (2015, December 25). Scientist claims UFO collided WITH TUNGUSKA meteorite to SAVE EARTH.
Bressan, D. (2019, July 01). For almost 100 years, Scientists puzzled over The Tunguska event.
Greenewald, J. (2021, February 16). UFOs: The Central intelligence Agency (CIA) Collection.
Maybe there is NO UFO [PDF].
NASA. (n.d.). The tunguska impact–100 years later.
The Physics Arxiv. (2020, October 09). Tunguska explosion in 1908 caused by asteroid grazing Earth.
Science X. (2004, August 10). Researchers say Tunguska event was an ufo CRASH: Debris of alien Spaceship found.
Selyukh, A., & Wadelton, B. (2019, June 29). Was this mysterious blast caused by aliens?

Written by Vladislav Tchakarov

Hello, my name is Vladislav and I am glad to have you here on Curiosmos. As a history student, I have a strong passion for history and science, and the opportunity to research and write in this field on a daily basis is a dream come true.

Write for us

We’re always looking for new guest authors and we welcome individual bloggers to contribute high-quality guest posts.

Get In Touch