Tunguska 1908: The Mystery Behind the Devastating Impact

There’s nothing like a gigantic explosion to set imaginations alight, especially if there are few witnesses, no investigation for over a decade and not much in the way of physical evidence to work out what happened. Today we’re investigating the 1908 Tunguska Event, a huge explosion that affected the planet from the Siberian wastelands to the English coast. While we think we’ve pretty much got a handle on what happened these days, there’s always room for alternative theories and, when something like this happens, you know some of those theories are going to be good. And by “good”, we don’t mean particularly well-thought out or credible, we mean straight-up weird.

What Was the Tunguska Event?

Imagine you’re a reindeer in early 20th century Russia. You’re hanging out by the Podkamennaya Tunguska river with your pals Yuri, Lev and Olena. It’s the 30th of June 1908, or, if you were still using the Julian calendar as Russia was at the time, it was only the 17th of June 1908.

If you were a reindeer, I suppose you didn’t really care much one way or the other. The day is clear and calm. You’re just moseying about, eating whatever reindeer eat when suddenly your attention is caught by a cylindrical object shooting across the sky.

“Odd,” you think. You nudge Olena but she’s not that interested and Yuri and Lev are too far away so you continue munching. The pipe-shaped object gets brighter and brighter so it’s like there are two suns, then the sky fills with smoke, banging noises like boulders tumbling or those things humans shoot at each other fill the air, the earth shakes like you’ve never known and everywhere around you trees are crashing over.

Yuri and Lev are flattened by the falling trees, Olena is burned to a crisp and all you see is blackness as your life swiftly comes to an end. Sorry, reindeer, you’ve just become a victim of the Tunguska Event. I did originally make your outcome a happy ending but felt this was more realistic as lots of reindeer did indeed perish.

Let’s get into more detail. As we said, it was a clear day in an area of Siberia that is located in what is currently known as the Krasnoyarsk Krai but back in 1908 was part of the Yeniseysk Governorate. This incident is known as the Tunguska event as it took place by the Podkamennaya Tunguska River. We may just refer to the area as “Tunguska” as we go along and I’m sure you’ll know what we mean.

While the area was and remains very sparsely populated, there were some people who witnessed the event and articles were published shortly afterward in various Russian newspapers. The accounts were all quite similar with people variously describing the start as an intense light in the sky.

A native Evenki tribesman reported: The morning was sunny, there were no clouds, our Sun was shining brightly as usual, and suddenly there came a second one! while the Sibir newspaper wrote of: some strangely bright (impossible to look at) bluish-white heavenly body.

This bright light moved downwards towards the earth and as it did, it: turned into a giant billow of black smoke according to Sibir. After that came a pillar of fire and an explosion so intense that it knocked down trees across an area of 2,150 km2 (830 sq mi) which is one and one third times the size of London or two and half times the area of New York City.

With this explosion came shock waves that registered at seismic stations across the globe and noise that was described by witnesses: as if rocks were falling or cannons were firing, a loud thunderclap and as if large stones were falling, or artillery was fired. This was accompanied by intense heat, hot winds and ground tremors. The explosion had happened in a remote area but buildings still had shattered windows and other minor damage.

The closest were at least 65 km or 40 miles from the epicenter but even those hundreds of kilometers away felt the effects. Anecdotally it’s been said that up to three people might have been killed during the Tunguska event but officially the confirmed death toll is a remarkable zero. That’s not counting the reindeer, obviously.

An estimated 80 million trees were felled, all falling outwards from the blast centre. In the middle of the blast zone stood a few remaining trees, upright but branchless and burned black.

According to Britannica.com: the energy of the explosion is estimated to have been equivalent to the explosive force of as much as 15 megatons of TNT—a thousand times more powerful than the atomic bomb dropped on Hiroshima, Japan, on August 6, 1945.

The explosion had been visible from over 800 km or 500 miles away and for days afterward, the night skies over Europe remained strangely bright, with people taking photographs at night without the need of a flash and reports of others in London able to read at midnight with no other light source.

There was no-one there to record the sound the explosion made but it has been estimated that it could have reached over 300 decibels, making it one of the loudest sounds in history.

What is now known as the Tunguska Event or Tunguska Incident, was the largest impact event on our planet in the time of recorded history. However, can it be called an impact event if no crater has ever been found? Why wasn’t there any sort of scientific expedition to the area until 1921 and even then not to the actual site of the explosion until 1927? As we said at the beginning, the event does have a rational explanation, if some of the finer details are still being quibbled over, but let’s explore some of the other theories people have thought up over the years.

Theories

It Was a UFO!

Well, it was a UFO to begin with. An unidentified flying object streaked across the sky before exploding into a Siberian forest. As there wasn’t anyone who was particularly close when it happened and no investigation was carried out for years, it could not initially be confirmed what the object was. But you know we’re talking about alien spacecraft here, not just being pedantic about what “UFO” stands for.

While the original witnesses didn’t make any mention of potential alien activity, the mysterious nature of some of the details of the event, plus Russia’s well renowned love of obfuscation ended up spawning more than one theory about extraterrestrial visitors with some even saying that this was Russia’s equivalent to Roswell. One theory that’s easy to disprove is that of a Martian spaceship coming into Earth for repairs but instead, blowing up. The spacecraft was powered by some sort of nuclear device, thus resulting in the gigantic explosion.

Sure, cool, cool, but where are the parts of the ship? Well, would you believe that in 2004, Russian media was alight with claims that extraterrestrial spaceship fragments had indeed been found at the site of the Tunguska event.

Yuri Lavbin, a member of the Tunguska Space Phenomenon foundation had headed an expedition to the Tunguska region and had found a metallic block that was widely reported as being from an extraterrestrial spaceship. So, was it? It’s not clear, as while Lavbin had it sent off for testing, he didn’t bother to wait for any results before making all his statements to the press so it hardly matters what the block was made of now as he’s already had his moment in the sun.

Also, he found this block somewhere way outside the normally agreed perimeter of the blast as he decided the object was headed in a different direction to where all the original eyewitnesses said it was going. He also decided to conclude that this proved that an alien spaceship had actually saved the planet from an incoming meteorite by blasting said meteorite to pieces and this bit he found was part of that device.

What could this object have been? Well, it’s possible that it was space related but unfortunately originating very much from this planet. Russia has had a very vigorous space program and in 1960 a test flight of Vostok 5 came down right near the Tunguska event area. Debris from that capsule is likely what Lavbin found, if he didn’t plant anything himself that is, and control panels and the general configuration of parts would not be familiar or easily recognisable by non-astronauts or space engineers.

Also, Lavbin had started his quest with the express intention of finding evidence of aliens. He said: We intend to find proof that not a meteorite but an extraterrestrial spaceship crashed with the Earth. And so voila, mission accomplished I guess.

There have been many other believers in the alien aspect to the Tunguska event with the nuclear engine of a spacecraft especially being a rich breeding ground for this theory. Because of the magnitude of the blast and the blast pattern of the trees, some sort of nuclear explosion has regularly been touted. 1908 was a wee bit early for humans to have been experimenting with nuclear bombs but maybe the Martians already had it down.

Scientist Aleksey Zolotov was convinced this was the source of the explosion and visited the site to carry out tests. While officially no significant radioactivity has been found at the event area, ruling out any kind of early or extraterrestrial nuclear shenanigans, Zolotov has claimed he has found elevated levels, although no proof has ever been given.

Another link that Zolotov has to this event, however, is a man called Alexander Kazantsev. The two were friends and Kazantsev was a well-known science fiction writer. After seeing the destruction the atomic bombs did at Hiroshima and Nagasaki and noting the similarities to the area around the Tunguska event, Kazantsev penned a fictional story about the martian in the spacecraft looking to land but ultimately blowing up.

So that’s where that whole story came from in the first place. What’s more difficult to work out is if Kazantsev wrote this in earnest or not. I have seen variously that it was all clearly supposed to be read as fiction, and also that this was his actual real life theory for what happened at Tunguska.

He was a ufologist and very interested in all things martian so it seems that fact and fiction just started blurring. Many people who believe the martian theory may have read or been influenced by the stories Kazantsev wrote and not realised they were supposed to be fiction. Or maybe they weren’t supposed to be fiction.

As I said, it’s hard to tell. What we can tell, however, is that no nuclear activity has been found at the site and no traces of extraterrestrial spaceships have ever been found. Unless it was all picked up and taken away, of course.

As previously mentioned, no real investigations were carried out until many years later, plenty of time to cover up traces of E.T.

Let’s face it, whenever there’s something spotted in the sky and unsatisfactory investigations are carried out deep in the wilderness, talk of aliens is always going to pop up. If you thought that was far-fetched, however, get a load of this:

It Was Nikola Tesla’s Death Ray!

Bear with us here. In some circles, what happened in the Tunguska event was actually Tesla trying to demonstrate his awe-inspiring remote death ray by gate crashing someone’s polar expedition but over shooting somewhat and instead destroying 80 million trees. Kind of an oopsie there. Is this even within the realms of possibility? Probably not but it makes for a fun few minutes.

In the early years of the 20th century, Nikola Tesla was all about wireless energy and the wireless transmission of power. He built a large transmission tower on an area of land in Long Island and called it “Wardenclyffe”. From here, he thought that as well as sending radio signals, he could also transmit power wirelessly to anywhere on the globe. Unfortunately, at this time Tesla was being shoved out by financial backers in favour of other inventors such as Marconi, and a financial panic in the early 1900s left him pretty much penniless.

By 1907, Tesla had made public comments about the destructive power of electrical waves, telling the New York Times: As to projecting wave energy to any particular region of the globe…this can be done by my devices. He went on to confirm that it could be focused very accurately, providing you had the correct measurements. In 1908, just before the Tunguska event, he wrote to the editor of the New York Times again, stating: When I spoke of future warfare I meant that it should be conducted by direct application of electrical waves without the use of aerial engines or other implements of destruction. He went on to say: This is not a dream. Even now wireless power plants could be constructed by which any region of the globe might be rendered uninhabitable without subjecting the population of other parts to serious danger or inconvenience.

So was Tesla saying that he had a remote weapon up and ready to go from Wardenclyffe Tower? When the Tunguska event occurred mere months later, there was no impact crater, no detailed eyewitness accounts of what happened and the devastation hit with the force of around 15 megatons of TNT which was within the wheelhouse of what Tesla had said his transmitter could produce. So why there and why then? Tunguska death ray theorists postulate that Tesla was doing secret tests with his wireless weapon and wanted to make a big statement to prove to everyone his idea was viable.

Around the same time as the Tunguska event, Admiral Robert Peary was trying to be the first person to reach the geographic north pole. Tesla apparently wanted to focus his ray in the arctic to create an event that Peary would immediately report back on. Then, I guess, Tesla would step out of the shadows and say: “that event at the North Pole that Peary witnessed? Ladies and gentlemen, that was me.”

I’m not sure what kind of display he was envisioning, did he want to etch “Tesla Was ‘Ere” in the ice? He could have easily killed Peary and his team and the whole idea seems a bit of an odd way to demonstrate your new toy. Anyway, the idea goes that Tesla had miscalculated the coordinates to aim his death ray and ended up blasting hundreds of square miles of the Siberian forest instead.

Why is this given any credence at all? In yet another letter to his BFF, the editor at the New York Times several years later, Tesla said that he had already made a transmitter powerful enough to wreak havoc wherever he wanted. In the 1915 letter, he wrote: It is perfectly practical to transmit electrical energy without wires and produce destructive effects at a distance. I have already constructed a wireless transmitter which makes this possible…When unavoidable, (it) may be used to destroy property and life.

In a letter to previous investor JP Morgan in 1934, Tesla seemed again to hint that he had created some sort of transmissible weapon:

The flying machine has completely demoralized the world, so much so that in some cities, as London and Paris, people are in mortal fear from aerial bombing. The new means I have perfected afford absolute protection against this and other forms of attack…These new discoveries I have carried out experimentally on a limited scale, created a profound impression.

So what do we think? Did Nikola Tesla as a last-ditch effort to recoup interest and money from his investors and save his reputation try to pull off a spectacular demonstration of a remote death ray or “teleforce” weapon as he preferred to call it, that went a bit awry? Personally, I’m in the “no” camp here. Tesla never expressly mentioned or claimed credit for the Tunguska event, maybe because he was embarrassed that he had missed his target or, more likely, because he had nothing to do with it at all.

There is nothing in the way of solid evidence to connect him to the event in any way, it’s mostly just coincidental wording that people have picked up on. There’s also no real evidence that he had a working teleforce weapon in the first place so the whole thing is just one big ball of rumour. There is little room for doubt when it comes to what really caused the Tunguska incident which unfortunately, closes the door on Tesla’s death ray. Sorry about that!

It was a Black Hole!

Now we’ve got the silly stuff out of the way, we can start to hone in on the more realistic theories, such as a black hole falling into the planet. Initially, I didn’t realise a black hole could fall anywhere so this was news to me. In 1973, physicists Michael P. Ryan and Albert A.

Jackson touted the theory that a small black hole had hit the Tunguska river area and passed straight through the planet. This would explain the lack of crater as the hole would be tiny. The appearance of this falling black hole would allegedly match eyewitness descriptions and the impact would cause the trees around to fall as they did.

When I said “small black hole” earlier, this is just in terms of the size of the thing. The mass would be enormous. But wait - what has happened to this mini black hole?

Is it just sitting in the centre of the earth biding its time? No, of course not. If we believe this theory then the black hole would have passed straight through the planet and popped out at the other side in the Atlantic somewhere.

Well, wouldn’t this have caused another Tunguska-sized shockwave to register? Yes, it would. Which is why we can discount this black hole theory.

The only seismic activity recorded in England, say, corresponded with the amount of time the shock waves took to travel from the impact point in Siberia. If the black hole had blasted out again, the seismic activity that would create would have been a lot closer to England and would have been recorded before the Tunguska activity reached it. This didn’t happen, ergo there was no second “exit” blast, ergo no black hole.

Moving on.

It was a Near Miss Asteroid!

Alright, we really are done with the silly ones now. In this penultimate theory, an asteroid the size of a football stadium basically just glanced off the Earth’s upper atmosphere before heading back out into the solar system. In 2020, Daniil Khrennikov and colleagues at the Siberian Federal University in Russia created a model showing various different bodies moving through space They concluded that a huge iron meteorite could have produced the craterless impact point, left glowing dust in the upper atmosphere and would not have left visible debris.

The team estimated that the asteroid would have been about 200 metres across, which is about half the height of the Empire State Building. Had it hit the ground, the crater would have been about 2 miles or just over 3 km wide.

The article I read on astronomy.com said, maybe playing it down a bit: It would also have had catastrophic effects on the biosphere, perhaps ending modern civilization.

A lucky escape for us, then.

This is a credible theory, although scientists usually go with the next one which is:

It Was a Comet Explosion! Or Asteroid Explosion!

OK, here’s the actual theory agreed upon by most scientists these days, although the details are not 100% solid. A comet or part of a comet or asteroid or part of a larger asteroid, headed for Earth but exploded in the atmosphere rather than hitting the ground. This is also known as a meteor air burst or superbolide. This accounts for witness sightings of the cylinder or tube moving across the sky, the bright light and the subsequent dark smoke and fire.

Newspaper reports at the time even referred to it as a meteorite and “unusual natural occurrence” so there was no real mystery even back then.

As the body didn’t hit the ground it left no impact crater but the force of the explosion was still massively strong, leaving those poor reindeer and trees with no chance. While the comet theory was all the rage for a while as the glowing skies it left behind could have been the residue of the comet’s tail, it’s since been decided that as a comet is made up of ice, it likely would not have lasted long enough in the Earth’s atmosphere to travel as far as it did.

Our best guess at the moment is that it was a rocky or stony asteroid. I’ve seen size estimates from 37 to 60 metres wide, and speed estimates from 54,000 kph to 97,000 kph but either way, this asteroid met with atmospheric friction, heat and pressure and annihilated itself between 5 and 10 kilometres above the Earth’s surface. We already know that there was no impact crater but surely there would be some sign of this asteroid?

Well, there is. There are tiny and microscopic spheres all over the area, in the soil and embedded in trees that have a chemical makeup not seen on Earth. They are of high nickel, low iron content, consistent with meteorites.

While the comet versus asteroid debate goes back and forth, we can safely assume that it was a celestial body or a smaller part of a larger body that came into contact with our atmosphere and exploded before it hit the ground.

Tying Up Loose Ends

Before we wrap up, let’s tie up a few loose ends.

We mentioned a few times that there was no scientific expedition out to the Tunguska site until many years after the incident. This wasn’t really for any conspiracy reasons, like the Russians hiding all traces of a UFO before letting the public loose on the area. It was for a combination of reasons including the remoteness of the area and the fact that in the immediate aftermath of the impact, nothing much else happened. Anyone venturing to the site would not have had access to any scientific tools that would have been able to give them much useful information and Russia was going through a lot at the time, coming off the back of a revolution and a whole lot of political upheaval.

Apparently the native Evenki people were also not keen on having visitors to their lands and saw the area as sacred. They wouldn’t let anyone go to the site even if they had tried. With World War One starting a few years later, there wasn’t any interest in funding a trip to see what might have happened until 1921.

Mineralogist Leonid Kulik took a team to the Podkamennaya Tunguska River basin to see if any meteoric iron could be found but the weather conditions were so hostile that they didn’t even make it to the blast area. It wasn’t until 1927 that he made it back, with the help of the Evenki people who I guess had thawed on the issue by this point. Kulik had assumed that a meteor had hit the region so found the lack of crater a surprise but he took lots of samples and photos in several other visits he made over the years.

Now, there have been many research trips and studies done about the Tunguska event, most reaching the same conclusions, apart from Yuri Lavbin and his recent UFO-finding mission.

Some people have queried the state the trees were left in after the blast. Trees at the centre of the explosion were scorched and had branches stripped off but hadn’t burned down and were still standing upright while trees all around had fallen down. If there had been fire as reported by eyewitnesses at the time, why hadn’t the whole forest burned down or at least the trees directly underneath the fire been burned to ash?

How could they still be standing? This is due to the fact that the explosion happened high above and was not caused by a physical object hitting the ground. Witnesses of the atomic bomb dropped on Hiroshima have reported a similar thing happened with trees there, branches were blown off but the main trunk was left standing.

As for the fire, according to Britannica.com: The radiant energy from such an explosion would be enough to ignite forests, but the subsequent blast wave would quickly overtake the fires and extinguish them. Thus, the Tunguska blast charred the forest but did not produce a sustained fire.

The Tunguska Effect

Even though we basically know what caused the explosion over the Tunguska river area, the event and region is still referenced in popular culture as some sort of mysterious thing. It’s been mentioned in Doctor Who and there was an episode of The X-Files called “Tunguska” involving a black oil, possible alien bacteria found in a meteorite and experiments on prisoners. I played a game on my old Nintendo DS called: Secret Files - Tunguska, however I don’t think I ever finished it as it’s a game where you can’t move on until you’ve done everything in a certain area and I think I just got stuck at some point. Nowadays I’d just cheat by looking online but I guess I had more integrity back then.

Many authors have used the Tunguska Event as inspiration including the aforementioned Alexander Kazantsev. In 2013, a show called “Siberia” aired which was filmed in the style of a reality show. Here’s part of the synopsis from IMDb: In 1908, an unexplained event occurred deep in the remote Siberian territory of Tunguska. Now, 100+ years later, 16 reality-show participants descend on Tunguska unknowing of the land’s mysterious past.

These contestants, from varied walks of life, will attempt to battle the elements and each other in a quest to survive the harsh winter and claim a large cash prize. What is initially met with unbridled enthusiasm quickly turns to sheer panic as a series of strange events begin to occur. It actually sounds quite good but - spoiler alert - it was filmed in Canada.

Could it Happen Again?

We live on a spinning rock surrounded by lots of other spinning, falling, burning and flying things so what are the chances that another Tunguska Event or something even worse could occur? Quite high, as it turns out. While an extinction level event such as a massive meteorite crashing into us only happens extremely rarely, smaller things make it through all the time. According to the Royal Museums Greenwich website: the real risk is possibly from the small, more frequent asteroids.

We expect a 10m meteoroid to hit every year, causing a 100m crater. Maybe only one in ten would hit a populated area - but considering the average density of England, that once-a-decade strike could still kill 12 people.

In February 2013 a mini Tunguska event took place, again over Russia, this time in the Chelyabinsk Oblast area. We have lots of photographic and video evidence of it this time and you can clearly see the meteor enter the Earth’s atmosphere before exploding with an intense light that was apparently brighter than the sun. It was about a third the size of the Tunguska meteor and released about 30 times the energy of the Hiroshima atomic bomb.

While no deaths were reported, over 7000 buildings were damaged with over 1400 people sustaining injuries relating to the indirect effects caused by the shockwave. Perhaps the most concerning aspect of this event is that no-one knew it was coming. Because of its relatively small size and the fact that it headed our way during the day, the Sun disguised it somewhat and at the time, it was not picked up by any observatories on the ground. Luckily it exploded away from a highly populated area and humanity got away unscathed again.

So how are we doing 10 years after this last surprise attack? Surely we can blast anything that threatens us out of the sky, right? Planetary astronomer Professor Alan Fitzsimmons says: Technology has come a long way in terms of how well you can detect asteroids, even as small as Chelyabinsk, but there’s still the chance that one could sneak through. And it’s quite likely that the next significant asteroid we have would be unannounced. Oh, right, thanks for that, Alan.

There are also other political factors in play now that weren’t such hot potatoes in 2013 such as the war in Ukraine and ongoing tensions between the US and China regarding spy balloons and other unidentified flying objects. An unannounced meteor making a cameo appearance could be cause for all kinds of flash responses.

There are systems being put in place which might help us avoid a collision with a near-Earth object (NEO) or another meteor airburst, though. In 2022, NASA and Johns Hopkins Applied Physics Laboratory tested their DART program which stands for Double Asteroid Redirection Test and basically involved crashing a spacecraft into an asteroid to see if it could get it to change course. It worked! This is useful for larger asteroids that we know are there, though, not the smaller ones such as those that have got through so far.

If you’re wondering why these last two events have happened in Russia and not anywhere else, it’s basically because Russia is so big - the Tunguska area and Chelyabinsk are over 1500 miles or 2400 km apart so not exactly right next to each other. There may have been loads of smaller asteroids that have burst over the ocean and nobody ever knew.

NASA is also working on a Near-Earth Object Surveyor - a space telescope - which is aiming to be completed by 2028. This will be tasked with looking out for potentially dangerous asteroids and comets, although again, the Chelyabinsk meteor was much smaller than the stuff the telescope will be concentrating on so I suppose we are all just hanging on by the skin of our teeth.

In the end, while it’s always fun to speculate, the Tunguska Event has been satisfactorily explained for a long time and we just have to cross our fingers and hope it doesn’t happen again. The truth is out there and in this case at least, it definitely wasn’t aliens.

Frequently Asked Questions

What was the Tunguska Event?

The Tunguska Event was a massive explosion that occurred on June 30, 1908, near the Podkamennaya Tunguska River in Siberia. It flattened trees over an area of 2,150 square kilometers and was visible from over 800 kilometers away.

What are some of the theories about the Tunguska Event?

Some theories about the Tunguska Event include a UFO or alien spacecraft, Nikola Tesla’s death ray, a black hole, a near-miss asteroid, and a comet or asteroid explosion in the atmosphere.

What is the most widely accepted explanation for the Tunguska Event?

The most widely accepted explanation is that a comet or asteroid exploded in the Earth’s atmosphere, causing a massive airburst without leaving an impact crater.

Why was there no scientific expedition to the Tunguska site until many years after the event?

The remoteness of the area, lack of immediate interest due to no further incidents, political upheaval in Russia, and resistance from the native Evenki people delayed scientific expeditions until 1921.

What evidence supports the comet or asteroid explosion theory?

Microscopic spheres with high nickel and low iron content, consistent with meteorites, have been found in the soil and embedded in trees in the Tunguska area.

Could the Tunguska Event happen again?

Yes, smaller asteroids and meteoroids frequently enter the Earth’s atmosphere. While larger extinction-level events are rare, smaller impacts like the Tunguska Event or the 2013 Chelyabinsk meteor are possible.

What was the energy equivalent of the Tunguska explosion?

The energy of the Tunguska explosion is estimated to have been equivalent to the explosive force of as much as 15 megatons of TNT, which is a thousand times more powerful than the atomic bomb dropped on Hiroshima.

What was the impact of the Tunguska Event on the environment?

The explosion felled an estimated 80 million trees, knocked down buildings over 65 kilometers away, and caused shock waves and ground tremors felt across the globe. The night skies over Europe remained strangely bright for days afterward.

What is the Tunguska Effect in popular culture?

The Tunguska Event has been referenced in various forms of media, including Doctor Who, The X-Files, video games like Secret Files - Tunguska, and TV shows like Siberia, often portraying it as a mysterious or unexplained phenomenon.

Sources

• Original Decoding the Unknown video: Tunguska 1908: The Mystery Behind the Devastating Impact
• Hero image source by Christian Herrmann / openverse, by-sa.