Mystery surrounding the cause of the massive Tonguska explosion has been solved

[Larry1]

Many of you are no doubt aware of what has been called the Tonguska Event: a massive fireball that landed in a remote region of Siberia in 1908, causing a huge impact.  The cause was a mystery for over a century, until very recently:

Meteoroid, Not Comet, Explains the 1908 Tunguska Fireball

On this day 105 years ago, Russians were reeling from the enormous fireball that streaked through the sky the day before and flattened almost 800 square miles of trees near the Podkamennaya Tunguska River.

It wasn’t a bird. It wasn’t a plane. And it sure as heck wasn’t Superman. But whatever it was, scientists found no trace of it in the charred rubble. It has taken researchers over a century to identify the extraterrestrial object—but in a recent paper, geoscientists revealed that the culprit was indeed a meteoroid.

The Hundred-Year Mystery

The burning chunk of rock struck Siberia on June 30, 1908 with a force 1,000 times more powerful than the atomic bomb dropped on Hiroshima. Over a century later, it is still the largest impact event in Earth’s recorded history. The area was uninhabited (luckily) but that did not mean the blazing ball of who-knows-what went unnoticed.

Scientific expeditions over the last century have combed the site and proposed a flurry of hypotheses: some said meteoroid; some said comet. The comet hypothesis was gaining traction by mid-century since such a mass of ice and dust would have vaporized when it hit the Earth’s atmosphere, causing an explosion without leaving any physical trace. But with so little evidence to go on, none of the theories could be proven.

A 1978 expedition came closer when it uncovered minuscule mineral samples embedded in peat at the epicenter of the blast. Researchers determined the samples to be 99.5 percent carbon with inclusions of other trace elements such as troilite and iridium. The amount of pressure required to form such samples suggested that the minerals were contained in a meteorite that smacked into the Earth. But these samples could also have formed when the heat and pressure of the space blast encountered rocks right here on our home planet, so the results were deemed inconclusive.

Taking a Closer Look

Armed with new and improved scanning technology, a group of geologists from Europe and North America decided to resurrect these mineral samples from their archive in the Ukrainian Academy of Sciences. They analyzed the samples with traditional microscopy techniques, mass spectrometry and high-powered X-rays—techniques that have been developed and refined in the past few decades—to give a much more detailed view, and published their findings in Planetary and Space Science in May.

While the carbon components of the samples weren’t necessarily from out of this world, the iridium concentration was ten times higher than in Earth rocks. The researchers were able to look at the surface structure and chemical composition of the samples in detail to determine that the mineral samples gathered at Tunguska most likely represent tiny bits of an iron meteorite. They suggest that the structure is the result of rapid cooling after an impact, and report that the mix of minerals matched those of other confirmed iron meteorites, like the one found in Arizona.

So it looks like the case is closed, just in time for Tunguska to blow out the candles on its 105th carbon-studded birthday cake. Let’s just try to keep the fire under control this time.

http://blogs.discovermagazine.com/d-brief/2013/07/01/meteoroid-not-comet-explains-the-1908-tunguska-fireball/#.UdXfafmceeu

Here is a description from an eye-witness to the explosion:

Testimony of Chuchan of Shanyagir tribe, as recorded by I.M. Suslov in 1926:[18]

We had a hut by the river with my brother Chekaren. We were sleeping. Suddenly we both woke up at the same time. Somebody shoved us. We heard whistling and felt strong wind. Chekaren said, 'Can you hear all those birds flying overhead?' We were both in the hut, couldn't see what was going on outside. Suddenly, I got shoved again, this time so hard I fell into the fire. I got scared. Chekaren got scared too. We started crying out for father, mother, brother, but no one answered. There was noise beyond the hut, we could hear trees falling down. Chekaren and I got out of our sleeping bags and wanted to run out, but then the thunder struck. This was the first thunder. The Earth began to move and rock, wind hit our hut and knocked it over. My body was pushed down by sticks, but my head was in the clear. Then I saw a wonder: trees were falling, the branches were on fire, it became mighty bright, how can I say this, as if there was a second sun, my eyes were hurting, I even closed them. It was like what the Russians call lightning. And immediately there was a loud thunderclap. This was the second thunder. The morning was sunny, there were no clouds, our Sun was shining brightly as usual, and suddenly there came a second one!
Chekaren and I had some difficulty getting out from under the remains of our hut. Then we saw that above, but in a different place, there was another flash, and loud thunder came. This was the third thunder strike. Wind came again, knocked us off our feet, struck against the fallen trees.

We looked at the fallen trees, watched the tree tops get snapped off, watched the fires. Suddenly Chekaren yelled 'Look up' and pointed with his hand. I looked there and saw another flash, and it made another thunder. But the noise was less than before. This was the fourth strike, like normal thunder.

Now I remember well there was also one more thunder strike, but it was small, and somewhere far away, where the Sun goes to sleep.

http://en.wikipedia.org/wiki/Tunguska_event

[Voyager36]

Many of you are no doubt aware of what has been called the Tonguska Event: a massive fireball that landed in a remote region of Siberia in 1908, causing a huge impact.  The cause was a mystery for over a century, until very recently:

It wasn't exactly a mystery, its been pretty much consensus for over 25 years that it was an explosive meteor event.

[Larry1]

It wasn't exactly a mystery, its been pretty much consensus for over 25 years that it was an explosive meteor event.

If this was the scientific consensus then I suppose it would not be a problem for you to provide an array of citations to that effect.

[mendeleyev]

Nice article, Larry.

[Fashionista]

Actually, it is well known in Russia, that the explosion was caused by a spaceship of aliens from a different universe who move backwards in time. The remains of the spaceship could only be found before 1908... 

[ML]

Actually, it is well known in Russia, that the explosion was caused by a spaceship of aliens from a different universe who move backwards in time. The remains of the spaceship could only be found before 1908... 

I like this story best.

Thank heavens it was not the Americans.

But if it had been us . . . then it would probably have been fake created by Hollywood.

[Voyager36]

If this was the scientific consensus then I suppose it would not be a problem for you to provide an array of citations to that effect.

Sure, a google search provides loads of research on the event, but I've never seen it ascribed anything other than a meteor by credible scientists. (Aliens, Bigfoot and Czarist A-bomb experiments notwithstanding.)  Do you have any reference to a scientific study showing it being anything other than that?
http://www.google.ca/search?sourceid=navclient&ie=UTF-8&rlz=1T4GGHP_enCA496CA496&q=1908+Tunguska+meteor+scientist
#rlz=1T4GGHP_enCA496CA496&q=1908+Tunguska+meteor+scientist&um=1&ie=UTF-8&hl=en&tbo=
u&tbm=bks&source=og&sa=N&tab=wp&ei=Qy7WUY7VI4bUyQH0toDQAw&fp=1&biw=1536&bih=
721&cad=b&bav=on.2,or.r_qf.&sei=6o3YUYq8CcmLiAKln4GQDw
The title of the article is somewhat misleading, to me "mystery" means something where there are a wide variety of hypothesis, and where there is no clear answer.
How were the Nazca lines drawn? Who was Jack the Ripper? Who wrote the Dead Sea Scrolls and what relationship did they have to Qumran? are examples of  true mysteries in my mind.
The article states there was some debate over whether it was a comet or an asteroid, but both are considered "meteors" if they impact Earth's atmosphere, and asteroids can have there orbits perturbed to become comets and vice versa.
Thanks to the member who sent me the link BTW.