The Great Tunguska Explosion

[The watcher]

Wasn't sure if there was already a thread about this, nor if this is the right area....but here goes nothing.

The Tunguska Event, or Tunguska explosion, was a massive explosion that occurred near the Podkamennaya (Lower Stony) Tunguska River in what is now Krasnoyarsk Krai of Russia, at around 7:14 a.m.^[1] (0:14 UT, 7:02 a.m. local solar time^[2]) on June 30, 1908 (June 17 in the Julian calendar, in use locally at the time).^[2]

Although the cause is the subject of some debate, the explosion was most likely caused by the air burst of a large meteoroid or comet fragment at an altitude of 5–10 kilometres (3–6 miles) above Earth's surface. Different studies have yielded varying estimates for the object's size, with general agreement that it was a few tens of metres across.^[3]

Although the meteor or comet burst in the air rather than directly hitting the surface, this event is still referred to as an impact. Estimates of the energy of the blast range from 5 megatons^[4] to as high as 30 megatons^[5] of TNT, with 10–15 megatons the most likely^[5] - roughly equal to the United States' Castle Bravo thermonuclear explosion set off in late February of 1954, about 1000 times as powerful as the bomb dropped on Hiroshima, Japan and about one third the power of the Tsar Bomba, the largest nuclear weapon ever detonated.^[6] The explosion knocked over an estimated 80 million trees over 2,150 square kilometres (830 square miles). It is estimated that the earthquake from the blast would have measured 5.0 on the Richter scale, which was not yet developed at the time. An explosion of this magnitude is capable of destroying a large metropolitan area.^[7] This possibility has helped to spark discussion of asteroid deflection strategies.

Although the Tunguska event is believed to be the largest impact event on land in Earth's recent history,^[8] impacts of similar size in remote ocean areas would have gone unnoticed before the advent of global satellite monitoring in the 1960s and 1970s.

[Gray-Wolf]

We have been quite fortunate not to cop for a medium sized impact over the developed world in the last century. There is footage of an 'earth grazer' ,taken in the U.S. I think, to highlight the point.

Insofar as an 'ocean impact' the 2004 tsunami should go some way to showing that we (coastal dwellers around the impact point) would have noticed any objects smashing into, or exploding above, a major ocean basin!!!

[A.J]

I concur, asteroid impacts of even just a modest size would cause tsunami or mega-tsunami....One reason to take a wikipedia entry with a pinch of salt...

Over the years there have been many (far-fetched) theories for the Tunguska explosion......from micro black holes to alien space craft blowing up, all utterly ridiculous! :lol: ........

The most compelling theory of course is that the explosion was caused by a comet fragment ....The date of the explosion coincides with the annual arrival of the Beta Taurid meteor shower (made of of the Comet Ecne remains)

[0000]

I concur, asteroid impacts of even just a modest size would cause tsunami or mega-tsunami....One reason to take a wikipedia entry with a pinch of salt...

Over the years there have been many (far-fetched) theories for the Tunguska explosion......from micro black holes to alien space craft blowing up, all utterly ridiculous! :lol: ........

The most compelling theory of course is that the explosion was caused by a comet fragment ....The date of the explosion coincides with the annual arrival of the Beta Taurid meteor shower (made of of the Comet Ecne remains)

There was theory of it being a UFO............or is that just urban legend aj?

[A.J]

There was theory of it being a UFO............or is that just urban legend aj?

urban legend?......more like a load of old cobblers to me....lol

Twas just fortunate, as mentioned by Grey-Wolf, that it didnt strike a populated area...It's been scientifically calculated that if the orbits had intersected 3 hours earlier, Moscow would have been wiped off the map, and planet earth's modern history would have no doubt been utterly re-written

[0000]

urban legend?......more like a load of old cobblers to me....lol

Twas just fortunate, as mentioned by Grey-Wolf, that it didnt strike a populated area...It's been scientifically calculated that if the orbits had intersected 3 hours earlier, Moscow would have been wiped off the map, and planet earth's modern history would have no doubt been utterly re-written

:lol:

What in ley man terms was the power of this explosion in say hiroshima bombs?

[A.J]

:lol:

What in ley man terms was the power of this explosion in say hiroshima bombs?

Dunno, I wasnt there....lol

According to a report, linked below, it equated to 500 Kilotons (half a megaton)...many estimates differ.....The Wikipedia article claims as much as 30 megatons, personally I believe a 30 megaton equivelent explosion would cause a much greater blast effect radius.....just an opinion though

http://www.psi.edu/projects/siberia/siberia.html

[0000]

Dunno, I wasnt there....lol

http://www.psi.edu/projects/siberia/siberia.html

bet you were :lol: cheers for the linky

[Chris Knight]

A chunk of cometary ice - mostly water and methane - creating a large air explosion as the methane ignited, vaporising the water, which accentuated the force of the explosion, as it eliminated the heating effects of the combustion, an of course flattening the forests below. Must have added a bit of greenhouse warming over the next few years.

[full_frontal_occlusion]

There was theory of it being a UFO............or is that just urban legend aj?

The exploding U.F.O. theory was popularised in the late 1960's by the Swiss author Erich von Daniken in his best selling book Chariots of the Gods.

"I prefer to adhere to the opinion of those who suspect that the nuclear explosion (Tunguska) was caused by an unknown spaceship's energy pile bursting. Fantastic? Of course. But does that make it impossible?" - Von Daniken.

The book is widely dismissed by scientists as psuedoscientific nonsense. Von Daniken used fabricated and fraudulently produced evidence to support his claims of extraterrestrial intelligence visiting the earth and even did a stretch behind bars for fraud.

http://www.scribd.com/doc/2368553/Erich-Vo...ots-of-the-Gods

ffO.

[noggin]

The book is widely dismissed by scientists as psuedoscientific nonsense. Von Daniken used fabricated and fraudulently produced evidence to support his claims of extraterrestrial intelligence visiting the earth and even did a stretch behind bars for fraud.

ffO.

It was a fascinating and exciting read, though! My friends and I were all gripped by it when it came out.

It was a theory, though, and like so many theories it now looks a bit daft. Some current theories may end up looking daft, too, but let's not go there!

Cough, cough, cough, AGW, cough, cough, cough.....sorry, do excuse me!

Sorry, apropos the subject of this thread...I reckon it was a meteor wot done it. It seems the most likely thing to me.

Edited September 26, 2008 by noggin

[Essan]

The Tunguska explosion was actually caused by a time machine accidently overloading and exploding. The time traveller had been using the machine to go back in time and find out what caused the explosion .......