Tunguska Impact Crater - Lake Cheko?

[BenBurch]

http://m.phys.org/news/2012-05-team-evidence-lake-cheko-impact.html

(Phys.org) -- Early on the morning of June 30th, 1908, a huge explosion occurred in a remote part of Siberia near the Podkamennaya Tunguska River. So great was the blast that trees were knocked down in neat rows for nearly a thousand square miles and the sky lit up from parts of Asia to Great Britain. What caused that explosion has never been firmly settled. Most researchers agree that it was the result of either a comet or meteoroid, with most leaning towards the former due to the lack of both an impact crater and meteoroid fragments. Now however, a research team from Italy says that they have found proof that it was in fact a meteorite that struck the Earth and that a nearby lake is the impact crater. They have published the results of their findings in Geochemistry, Geophysics, Geosystems.

<SNIP>

I fished out a Google Earth image of it (attached) - yes that looks like it might be an astrobleme!

[Craig B]

http://m.phys.org/news/2012-05-team-evidence-lake-cheko-impact.html I fished out a Google Earth image of it (attached) - yes that looks like it might be an astrobleme! But didn't the first explorers of the area find a tree pattern with a central group still erect, stripped of leaves and bark, and millions of others felled pointing away from this central area, indicating an air burst above an identified location in the forest?

[MG1962]

I would love to know what they did that the countless expeditions to the area since the 1920's didn't do

[metzomagic]

I would love to know what they did that the countless expeditions to the area since the 1920's didn't do

From the article in the OP:

The team came to this conclusion after performing seismic measurements on the lake bottom in 1999 which showed that sentiment had been building for just about a hundred years, which would of course put it close to the Tunguska Event and also gave evidence of something dense near the middle of the lake.

Further evidence came to light they say in 2009 when they returned to the lake and performed a magnetic survey, which they say showed an anomaly in the same location as their seismic measurements had detected. Now, after three more years of studying evidence they collected from the site, they’ve concluded that Lake Cheko is indeed an impact crater and that the dense object beneath the lakebed is the smoking gun.

So, still inconclusive until someone actually digs up whatever's at the bottom of the lake and analyses it.

[RecoveringYuppy]

But didn't the first explorers of the area find a tree pattern with a central group still erect, stripped of leaves and bark, and millions of others felled pointing away from this central area, indicating an air burst above an identified location in the forest?
That wouldn't rule out a surviving piece causing a crater. There are records of single events that caused multiple craters.

I would love to know what they did that the countless expeditions to the area since the 1920's didn't do

Apparently, they used a magnetometer and did sedimentary analysis of the lake bottom (link at the top of Ben's post may have gone unnoticed?)

[BenBurch]

But didn't the first explorers of the area find a tree pattern with a central group still erect, stripped of leaves and bark, and millions of others felled pointing away from this central area, indicating an air burst above an identified location in the forest?

15 years later. That's a long time.

[Craig B]

That wouldn't rule out a surviving piece causing a crater. There are records of single events that caused multiple craters. Leonid Kulik was alert to any possible impact features, which he expected to find. He missed a lake? May we suppose that there is no cartographic or anecdotal record of this lake prior to 1908? If so, why did he not investigate it? Would not the same tree-fall phenomenon have been evident near this lake, as well as many other signs of its recent creation, had it been an astrobleme?

[Craig B]

15 years later. That's a long time. Not in the lifetime of conifers in a sub-Arctic environment.

[BenBurch]

Not in the lifetime of conifers in a sub-Arctic environment.

How many storms in the interval?

Also, trees could be left standing in places where terrain caused the blast wave to cancel itself or where there was a declivity.

[BenBurch]

Leonid Kulik was alert to any possible impact features, which he expected to find. He missed a lake? May we suppose that there is no cartographic or anecdotal record of this lake prior to 1908? If so, why did he not investigate it? Would not the same tree-fall phenomenon have been evident near this lake, as well as many other signs of its recent creation, had it been an astrobleme?

But was he looking for non-round structures? Some astroblemes like the Río Cuarto craters are oblong or teardrop-shaped.

[Checkmite]

How many storms in the interval?

Also, trees could be left standing in places where terrain caused the blast wave to cancel itself or where there was a declivity.

Yes but this doesn't explain why the radial pattern of felled trees is centered around that stand of trees and not the hypothesized lake impact site.

[Olowkow]

http://www.space.com/3996-crater-solve-1908-tunguska-meteor-mystery.html
To really find out if this is an impact crater," Longo said, "we need a core sample 10 meters (33 feet) into the bottom? in order to investigate a spot where the team detected a ?reflecting? anomaly with their seismic instruments. They think this could be where the ground was compacted by an impact or where part of the meteorite itself lies: The object, if found, could be more than 30 feet in diameter and weigh almost 1,700 tons — the weight of about 42 fully-loaded semi-trailers

This was found nearly 5 years ago. I have a feeling that if they seriously thought there was a huge chunk of meteor down there, they would have been onto it by now, and have samples worth big bucks.

[BenBurch]

Does anybody know if the Czar's maps of this area are available online anywhere? This was hellishly remote, and I wonder what level of detail we might expect?

[BenBurch]

Yes but this doesn't explain why the radial pattern of felled trees is centered around that stand of trees and not the hypothesized lake impact site.

Shock waves do strange things. And there could have been an airburst that still left a fragment large enough to form the lake. I have seen a number of multi-part fireballs over the years.

[MG1962]

That wouldn't rule out a surviving piece causing a crater. There are records of single events that caused multiple craters.

My concern is they are suggesting a one meter piece of this object caused a crater bigger than the Barringer crater.



Apparently, they used a magnetometer and did sedimentary analysis of the lake bottom (link at the top of Ben's post may have gone unnoticed?)

I probably didn't explain my point - people have been using the same technology since the 1970's to find pieces of this object. A large number of these anomalies have turned up in the Great Hollow especially around Lovy's Bog, unfortunately all attempts at core samples have failed to identify what they are.

What has been found are large quantities of tiny metal spheroids plastered all over the place - something like 20Kgs have been retrieved since 1961.


As a complete aside to the above Vladimir Rubtsov mentions that at the Centenary celebrations in 2008 among the usual stone markers and plaques. Some one had laid a stone in memory of a spaceship that crashed in Siberia flown by a Japanese crew :boggled:

[MG1962]

Leonid Kulik was alert to any possible impact features, which he expected to find. He missed a lake? May we suppose that there is no cartographic or anecdotal record of this lake prior to 1908? If so, why did he not investigate it? Would not the same tree-fall phenomenon have been evident near this lake, as well as many other signs of its recent creation, had it been an astrobleme?

There were no maps - The lake is actually nearly 5 miles from the impact zone. It was only during the 1958 expedition the lakes origins was considered. However the 1961 trip pretty much argued the lake was much older than 1908 - Disputing this seems to be one of the corner stones of the Italian research

[Checkmite]

Shock waves do strange things.

"God moves in mysterious ways"? Nay, rather shock waves propagate in an understood and predictable manner surely, and I expect an impact site situated away from its associated shock wave is something that there's probably only a very small number of possible explanations for.

And there could have been an airburst that still left a fragment large enough to form the lake. I have seen a number of multi-part fireballs over the years.

That makes a little more sense. But there are some important questions: is the lake the proper size, shape, and orientation to have been created by a 30-foot, 1,700 ton meteorite impact, falling in a trajectory suggested by witness descriptions (there are some witness descriptions, IIRC); and what other effects would such a tremendous impact have had (and do we find these at the location)?

[MG1962]

"God moves in mysterious ways"? Nay, rather shock waves propagate in an understood and predictable manner surely, and I expect an impact site situated away from its associated shock wave is something that there's probably only a very small number of possible explanations for.

The biggest problem with all the investigations of the site is no one can explain the shock wave. When you see the plots of the damage area is looks like the wings of a butterfly. As of 2009 no computer sim has been able to mix all the known factors to create this blast effect

[Olowkow]

I remember seeing this on TV, apparently NG quite a while back. I am fairly certain they mentioned the "butterfly" pattern was duplicated, and they were quite pleased with the results of the research.

A simulation of the Asteroid Airburst that may have caused the 190-8 TUnguska Event. Done by Planetary Geologist Peter Schultz on the NASA Ames Vertical Gun Range in August of 2009. A projectile the size of a ball bearing is fired at 15 thousand miles per hour into a sheet of mylar (off camera) which causes it to explode in mid-air. The fireball streaks down to the surface, but the damage is caused by the shockwave from the midair explosion. The toothpicks stand in for the trees in the Tunguska. A verison of this animation was used in the National Geographic Channel program "Expedition Apocalyppse"



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[phunk]

The biggest problem with all the investigations of the site is no one can explain the shock wave. When you see the plots of the damage area is looks like the wings of a butterfly. As of 2009 no computer sim has been able to mix all the known factors to create this blast effect

I'm fairly certain I've seen a documentary where the event was simulated in miniature and the pattern recreated. If I remember right, they had small explosives travel down a guide wire (to precisely control the angle) towards a recreation of the tunguska landscape, and found the proper altitude and approach angle to recreate the pattern that was seen.

ETA: Apparantly it's been done more than once, the one Olowkow linked isn't the one I remember.

[Olowkow]

I'm fairly certain I've seen a documentary where the event was simulated in miniature and the pattern recreated. If I remember right, they had small explosives travel down a guide wire (to precisely control the angle) towards a recreation of the tunguska landscape, and found the proper altitude and approach angle to recreate the pattern that was seen.

ETA: Apparantly it's been done more than once, the one Olowkow linked isn't the one I remember.

Right. I remember seeing it from above, so the one in the video is not the same as the experiment that I recall. The program I saw definitely showed a butterfly pattern, in very good light.

[steve s]

Years ago I saw a program where a Russian scientist recreated the butterfly pattern using matchsticks propped up on small wires. I think he did this back about the '50s or '60s.

Steve S

[The Man]

Years ago I saw a program where a Russian scientist recreated the butterfly pattern using matchsticks propped up on small wires. I think he did this back about the '50s or '60s.

Steve S

That’s the one I recall as well. They showed that it was an aerial explosion at a 30 degree approach that could produce the pattern as I recall.

http://unitedcats.wordpress.com/2008/06/30/tunguska-june-30-1908-the-sky-split-in-two-and-fire-appeared-high-and-wide-over-the-forest/


Later expeditions discovered microscopic glass beads in the soil and downed/dead trees at the site that are consistent with asteroidal material. While the site is still being studied and there is much left to learn, today’s science thinks it has the basic answer. It’s conjectured that a stony asteroid 50-60m in diameter exploded in the air 4-6 miles above the ground, such explosion caused by the huge amount of heat generated when the extremely fast moving rock entered the Earth’s atmosphere. The Russians have even been able to replicate the butterfly pattern of fallen trees by experimenting with explosives sliding down wires amid matchstick forests, showing the original object struck earth at about a 30% angle.


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


The explosion's effect on the trees near ground zero was replicated during atmospheric nuclear tests in the 1950s and 1960s. These effects are caused by the shock wave produced by large explosions. The trees directly below the explosion are stripped as the blast wave moves vertically downward, while trees farther away are knocked over because the blast wave is travelling closer to the horizontal when it reaches them.
Soviet experiments performed in the mid-1960s, with model forests (made of matches on wire stakes) and small explosive charges slid downward on wires, produced butterfly shaped blast patterns strikingly similar to the pattern found at the Tunguska site. The experiments suggested that the object had approached at an angle of roughly 30 degrees from the ground and 115 degrees from north and had exploded in mid-air.[30]

[jenkoul]

For something completely different in the way of Tunguska science, you might check out Bill DeSmedt's "The Singularity Files" -- just published as a free ebook for Kindle, Nook, and iBooks.
TSF attempts to resurrect Al Jackson and Mike Ryan's 1973 primordial black hole impactor theory of the Tunguska Event. It'd be interesting to see what this forum's members think about that.

[Olowkow]

http://www.amazon.com/Singularity-Audiobook-Seminars-Sequence-ebook/dp/B0080JGVPG

Thanks, I'll check it out. And welcome to JREF, jenkoul.

[BenBurch]

One other possibility; The lake is an astrobleme but much older than Tunguska.

[Craig B]

One other possibility; The lake is an astrobleme but much older than Tunguska. Could be! Siberia seems to attract impactors. Another biggie:Sikhote-Alin is an iron meteorite that fell in 1947 on the Sikhote-Alin Mountains in eastern Siberia. Though large iron meteorite falls had been witnessed previously and fragments recovered, never before in recorded history had a fall of this magnitude been observed. An estimated 70 tonnes of material survived the fiery passage through the atmosphere and reached the Earth. Is it Kansas in the USA that seems to have more than its fair share of meteorites?

But I'm not too keen on the tiny black hole idea, as nobody has ever observed one of these entities, although they are permitted by theory.

[MG1962]

But I'm not too keen on the tiny black hole idea, as nobody has ever observed one of these entities, although they are permitted by theory.

My favorite theory is the one that a space battle involving two ships in high Earth orbit - Apparently study of Russian jet combat tactics, and comparing them to eyewitness accounts made the answer obvious....to someone at least lol

[Craig B]

My favorite theory is the one that a space battle involving two ships in high Earth orbit - Apparently study of Russian jet combat tactics, and comparing them to eyewitness accounts made the answer obvious....to someone at least lol One of the implications of the tiny black hole theory is, of course, that the TBH travelled straight through the earth and created a similar disturbance at its exit point, say, antipodeal to the Tunguska region where it originally impacted. I have read discussion of this possibility. We're looking for a catastrophe a millisecond after the Tunguska event, but in the southern hemisphere. Any candidates?

[RecoveringYuppy]

One of the implications of the tiny black hole theory is, of course, that the TBH travelled straight through the earth and created a similar disturbance at its exit point, say, antipodeal to the Tunguska region where it originally impacted. I have read discussion of this possibility. We're looking for a catastrophe a millisecond after the Tunguska event, but in the southern hemisphere. Any candidates?
I can't find details on the trajectory right now, but it is described as "shallow". So the exit point wouldn't be antipodal. It would be "nearby" where nearby is a relative term depending on exactly how shallow the trajectory was.

[MG1962]

One of the implications of the tiny black hole theory is, of course, that the TBH travelled straight through the earth and created a similar disturbance at its exit point, say, antipodeal to the Tunguska region where it originally impacted. I have read discussion of this possibility. We're looking for a catastrophe a millisecond after the Tunguska event, but in the southern hemisphere. Any candidates?

Not that I am aware of - However the black hole theory has to ignore one of the major pieces of evidence about the blast - The days of no night - or 72 hours before the impact areas as far west as the mid Atlantic reported marked increase in sky glow. And when I mean increase, I mean being able to read a newspaper outside at 2am in the morning. Over the three days the phenomena contracted to the East and intensified till dawn on June 30.

For weeks after the event an American observatory tracked a high altitude dust cloud that corresponded with the events at Tunguska

[mummymonkey]

Looking at Google Maps the lake looks entirely consistent with the rest of the river system in that area. Lots of meanders, oxbow lakes and such.

[davefoc]

I've seen the efforts to determine if Lake Cheko is an impact site of the Tunguska Event described in at least one television documentary previously. This was the first time I've read through a formal report on the research.

Their case as I see it:

1. The morphology of the Lake is unusual for the area. The surface of the lake bottom is roughly conical. They suggest that this might have been caused by an impact object that passed through layers of soft material (swampy and permafrost) and then exploded. The idea is that this would have blown out a roughly conical Lake.

2. Magnetic anomalies that rule out the possibility of an iron rich object but are consistent with a stony meteorite.

3. Seismic anomaly that suggests an object or disturbed material near the bottom of the Lake.

My guess is that they are right. If I understand the maps correctly the location of the lake is on a line that passes through the theoretical center of the blast and is in the theoretical direction of the blast. This adds a bit of plausibility to the situation since a heavier object might pass over the center of the blast.

The caveat is that I didn't understand a lot of the details of their test results and how significant their results were with regard to the anomalous results they reported.

As to some of the points raised:

Craig B: He [Kulik] missed a lake?

Given how difficult it is to investigate whether this is an impact caused lake or not the fact that Kulik "missed" it doesn't seem surprising to me.

jenkoul: Tiny black holes

Not even worth a look IMHO. Some kind of extraterrestrial impact object has been proven from my point of view and the micro black hole theory has been disproved.

MG1962: 1961 expedition disproved impact caused the Lake.

That might be so. I'm not familiar enough with the opposing information to have much of an opinion. The authors of this paper suggest that the lake bottom below the 1908 layer is disturbed and there are laminar layers above the 1908 layer. I don't know enough about the evidence to have a feel for whether they are right or not.

[BenBurch]

...

Another biggie: Is it Kansas in the USA that seems to have more than its fair share of meteorites?

...

Western Kansas does not have more meteorites than normal, but they are much easier to find.

There are large areas where the soil contains NO rocks at all. None. Settlers had to build sod homes as a result (also no large stands of trees.)

So, if you find a rock it is either old concrete, an imported rock like from the railroads or road building, or a meteorite.

[MG1962]

MG1962: 1961 expedition disproved impact caused the Lake.

That might be so. I'm not familiar enough with the opposing information to have much of an opinion. The authors of this paper suggest that the lake bottom below the 1908 layer is disturbed and there are laminar layers above the 1908 layer. I don't know enough about the evidence to have a feel for whether they are right or not.

I am comfortable with the idea there is a piece of the thing in the lake, but not the lakes creation caused by the impact. There has also been a British expedition in the 80's to the area. Their area of focus was not the lake but the flora around the lake. In their opinion they saw no environment disruptions that would indicate a meteor strike.

I have not read their results directly, but only through a second hand source

[MG1962]

Western Kansas does not have more meteorites than normal, but they are much easier to find.

There are large areas where the soil contains NO rocks at all. None. Settlers had to build sod homes as a result (also no large stands of trees.)

So, if you find a rock it is either old concrete, an imported rock like from the railroads or road building, or a meteorite.

Limestone outcrops are common to the point where there is a local tradition of building fence posts out of the stuff - but other than that as you suggested any rock you find probably came from somewhere else

[BenBurch]

Limestone outcrops are common to the point where there is a local tradition of building fence posts out of the stuff - but other than that as you suggested any rock you find probably came from somewhere else

Right, but miles and miles between those outcrops in places.

A story I heard had kids going out rock hunting and their parents smiling and letting them find out for themselves that grandpa's farm had no rocks, and they came back with not one, but two meteorites!

[jhunter1163]

I think that a good case can be made (Davefoc already laid it out above) that Lake Cheko is in fact an impact feature, although probably not from 1908. I'm convinced. :)

[Marduk]

I remember Arthur C Clarke speculating on "Mysterious World" that it was an alien spaceship that exploded while trying to reach Lake Baikal to take on fresh water to cool its overheating reactor

this for me is by far the most interesting explanation, not because Arthur said it, but because I was about 8 when he did
:D

[steve s]

I remember Arthur C Clarke speculating on "Mysterious World" that it was an alien spaceship that exploded while trying to reach Lake Baikal to take on fresh water to cool its overheating reactor


As Neill deGrasse Tyson said, if the aliens are so stupid that they can travel across the galaxy but not land safely without crashing, then I don't want to meet them.

Steve S

[MG1962]

I remember Arthur C Clarke speculating on "Mysterious World" that it was an alien spaceship that exploded while trying to reach Lake Baikal to take on fresh water to cool its overheating reactor

this for me is by far the most interesting explanation, not because Arthur said it, but because I was about 8 when he did
:D

Unfortunately Arthur borrowed that idea from a Russian "Alexander Kazantev" who's Wiki entry really doesn't do him justice. He is a very well regarded engineer who in 1945 put the nuclear accident idea together, which was extremely influential for the next twenty years in Tunguska research.

Even today there is still debate about radiation levels at the site and his idea is still to definitively dismissed.

[Craig B]

Craig B: He [Kulik] missed a lake?

Given how difficult it is to investigate whether this is an impact caused lake or not the fact that Kulik "missed" it doesn't seem surprising to me. What I meant was: Kulik found unmistakable signs of an enormous explosion, even in a place where there were no obvious impact features. Would not a large impact feature like a lake have been at the centre of equally obvious signs of at least as great an explosion? And Kulik was looking for precisely that sort of thing, a crater, which would of course have filled with water very quickly after it was formed.

[MG1962]

What I meant was: Kulik found unmistakable signs of an enormous explosion, even in a place where there were no obvious impact features. Would not a large impact feature like a lake have been at the centre of equally obvious signs of at least as great an explosion? And Kulik was looking for precisely that sort of thing, a crater, which would of course have filled with water very quickly after it was formed.

No because the lake was outside the main area of destruction - the expedition concentrated on a large boggy area in the center of the Great Hollow and pretty close to the center of the destruction

[Craig B]

Even today there is still debate about radiation levels at the site and his ideathat it was an alien spaceship that exploded while trying to reach Lake Baikal to take on fresh water to cool its overheating reactoris still to definitively dismissed. I must admit that I have a strong inclination to dismiss it very definitively. Even if traces of radioactivity are found, can we conclude that alien spaceships with leaky water-cooled reactors are a plausible source?

[Craig B]

No because the lake was outside the main area of destruction - the expedition concentrated on a large boggy area in the center of the Great Hollow and pretty close to the center of the destruction Yes, I can see that. An interesting question, to which I don't know the answer: are there still, at the present time, clear signs of destruction in the area investigated by Kulik? If so, is there anything comparable in the vicinity of the lake?

Edited to add: sorry, I see you answered that at #35, that there is no such evidence near the lake.

[steve s]

Even if traces of radioactivity are found, can we conclude that alien spaceships with leaky water-cooled reactors are a plausible source?

But in sci-fi movies, spaceships always have a lot of pipes with steam coming out of them.

Steve S

[The Man]

I remember Arthur C Clarke speculating on "Mysterious World" that it was an alien spaceship that exploded while trying to reach Lake Baikal to take on fresh water to cool its overheating reactor


As Neill deGrasse Tyson said, if the aliens are so stupid that they can travel across the galaxy but not land safely without crashing, then I don't want to meet them.

Steve S

Yep, undoubtedly the first, in this solar system, to fall victim to texting while driving.



“Entering atmosphere and aerobraking to vicinity of remote coolant source, will report back upon lan…”

[MG1962]

that it was an alien spaceship that exploded while trying to reach Lake Baikal to take on fresh water to cool its overheating reactor I must admit that I have a strong inclination to dismiss it very definitively. Even if traces of radioactivity are found, can we conclude that alien spaceships with leaky water-cooled reactors are a plausible source?

Well the Soviets where in enchanted with the idea. Even Sergey Korolev was involved in some of the research at one point. For them the key was finding a bit of the object that brought this all on - Hopefully the Italians may be on the verge of delivering that piece of the puzzle

[esquel]

RE: the 'tiny metal spheroids' -- can you point me to a scholarly article on the recovery of same? My Google-fu only comes up with they usual crank sites, and unrelated articles about meteorite recovery.

AFAIK, the jury is still out on the actual mechanism for the explosion. I do recall a Discovery channel show a couple of years ago, about sending various scientists --geologists, botanists, et. al. -- out to look at the Tunguska area. Aside from rediscovering that it's a really nasty place to try to travel about, none of the evidence they collected really shed much more light on the impactor. I do remember that the geologist failed to find two of the 'marker minerals', coesite and stishosite, that indicate the type of high velocity impact associated with a meteorite or comet strike. The botanist found the expected tree damage from an airburst (after over 100 years of overgrowth), but nothing new. They were talking about Lake Chieko then as well, but failed to find anything significant.

[MG1962]

RE: the 'tiny metal spheroids' -- can you point me to a scholarly article on the recovery of same? My Google-fu only comes up with they usual crank sites, and unrelated articles about meteorite recovery.

AFAIK, the jury is still out on the actual mechanism for the explosion. I do recall a Discovery channel show a couple of years ago, about sending various scientists --geologists, botanists, et. al. -- out to look at the Tunguska area. Aside from rediscovering that it's a really nasty place to try to travel about, none of the evidence they collected really shed much more light on the impactor. I do remember that the geologist failed to find two of the 'marker minerals', coesite and stishosite, that indicate the type of high velocity impact associated with a meteorite or comet strike. The botanist found the expected tree damage from an airburst (after over 100 years of overgrowth), but nothing new. They were talking about Lake Chieko then as well, but failed to find anything significant.

Rubstov doesn't give a reference for the data other than it was the ITEG expedition of 1961.

Here is a link to his book - It is basically a chronicle of Russian investigations of the site and the event dating back to meteorological records from June 1908

http://www.amazon.com/The-Tunguska-Mystery-Astronomers-Universe/dp/0387765735

[Travis]

It was a time traveler with a faulty gravity drive.


You can put money on it. :D

[Craig B]

Well the Soviets where in enchanted with the idea. Even Sergey Korolev was involved in some of the research at one point. For them the key was finding a bit of the object that brought this all on - Hopefully the Italians may be on the verge of delivering that piece of the puzzle To be sure, if anyone finds material or artefacts which can with very high probability be attributed to a mishap involving an alien spacecraft propelled by a defective nuclear reactor which was on a course for Lake Baikal, for the purpose of picking up water there; and that the nature of this physical evidence precludes a more mundane origin; then my hostility to the theory will evaporate.

But I must warn in advance: pieces of twisted and blackened metal will not suffice. Something like a "black box" with an hour or so of video and audio record of events on the "flight deck" of the doomed craft, is what I would need.

[The Man]

To be sure, if anyone finds material or artefacts which can with very high probability be attributed to a mishap involving an alien spacecraft propelled by a defective nuclear reactor which was on a course for Lake Baikal, for the purpose of picking up water there; and that the nature of this physical evidence precludes a more mundane origin; then my hostility to the theory will evaporate.

But I must warn in advance: pieces of twisted and blackened metal will not suffice. Something like a "black box" with an hour or so of video and audio record of events on the "flight deck" of the doomed craft, is what I would need.

Nope, everyone knows that aliens have 'grey boxes'. You just can't tell where they've been or who they probed last.


@MG1962, so what do you think the Italian explores might find? From the image linked by BenBurch it looks like a fairly normal tributary development (considering the apparent topology) to me. Sorry I'm only trying to recall what I remember from river and stream dynamic documentaries (and early Earth science in school). As silt builds up on river banks the path tends to diverge creating bends in the river. Eventually the force of the flow can overwhelm that bend and the river becomes 'straighter' again. This cycle is repeated. Someone with more knowledge of river hydrodynamics or geology may be able to confirm or refute what I'm thinking. However it seems to me that what appears to be the inlet, confined by local topology upstream appears to reverse upon itself. Preventing that normal cycle and creating the lake and the lush vegetation (that would be on the inside of the bend). If my surmise (and recollection of such imaging) is correct the grey you see in the lake, before and beyond, is silt (small particles of dirt) and how it is developing down stream from the lake making another bend around a more obvious extent of the local topology that is more obscured upstream by the increased vegetation (in the image) . In fact not only is there a smaller pool of water inside the vegetative area (more swamp like at that apparent elevation) but the inlet has formed a small finger lake where the river silt builds up (up stream) before entering the lake. Just everything about what I see in that image and what I think I know about geology and river dynamics screams natural formation, but heck I certainly ain't no expert and if it seemed definitively unnatural (not formed by just topology) I guess there probably won't be any controversy.

[MG1962]

To be sure, if anyone finds material or artefacts which can with very high probability be attributed to a mishap involving an alien spacecraft propelled by a defective nuclear reactor which was on a course for Lake Baikal, for the purpose of picking up water there; and that the nature of this physical evidence precludes a more mundane origin; then my hostility to the theory will evaporate.

But I must warn in advance: pieces of twisted and blackened metal will not suffice. Something like a "black box" with an hour or so of video and audio record of events on the "flight deck" of the doomed craft, is what I would need.

I completely agree - extraordinarily claims require extraordinary proof. I think the failed reactor and heading for the lake was all wishful thinking by a reasonable science fiction author who was a pretty good engineer.

If we are to entertain the theory I think it would be in terms of a much more mundane situation. Something broke and it crashed. At varying times, there have been some 50 expeditions to the area and some have turned up odd finds in chemistry and claims of titanium and aluminium at the micron level from core samples

Rubstov seems pretty dismissive of these claims, but doesn't say why, so I cant speak to the validity of the information - It could have been crackpot researchers, or other reasons

[MG1962]

@MG1962, so what do you think the Italian explores might find? From the image linked by BenBurch it looks like a fairly normal tributary development (considering the apparent topology) to me. Sorry I'm only trying to recall what I remember from river and stream dynamic documentaries (and early Earth science in school).

I believe the Italians have found nothing - from what little of their paper is accessible on line I just don't see what they have done differently to justify their findings

I dont feel comfortable trying to identify the origins of the lake as it is an area I have had no real interest in.

I do however hope I am wrong - Finding a piece of this beastie would help solve a lot of questions, but if my belief in the comet theory is correct, nobody is ever going to find much of anything

[BenBurch]

that it was an alien spaceship that exploded while trying to reach Lake Baikal to take on fresh water to cool its overheating reactor I must admit that I have a strong inclination to dismiss it very definitively. Even if traces of radioactivity are found, can we conclude that alien spaceships with leaky water-cooled reactors are a plausible source?

There are very few coolants with the stability and thermal characteristics of water. If you burn hydrogen, it's also fuel.

[Craig B]

There are very few coolants with the stability and thermal characteristics of water ... You mean that if Lake Baikal consisted of some other liquid, like mercury or sulphuric acid, the stricken water-cooled nuclear reactor-powered alien spacecraft wouldn't have been heading in that direction? I'm sure you're right. It would probably have set a course for Lake Ladoga in that case.

[phunk]

No because the lake was outside the main area of destruction - the expedition concentrated on a large boggy area in the center of the Great Hollow and pretty close to the center of the destruction

But certainly there would be a great amount of ejecta. Not to mention the fact that the river downstream of the new lake would stop flowing while the lake filled. Surely these things would be noticed?

[Craig B]

But certainly there would be a great amount of ejecta. Not to mention the fact that the river downstream of the new lake would stop flowing while the lake filled. Surely these things would be noticed? The second might not have been reported to Kulik by the tiny number of trappers and reindeer herders who might conceivably have noticed this phenomenon. But I think the ejecta and tree fall which would have occurred might very well have been noticed, if the lake is only a few miles from the location studied by the expedition.

Indeed, relics of these impact features should be evident to this day, and seemingly they are not.

[MG1962]

But certainly there would be a great amount of ejecta. Not to mention the fact that the river downstream of the new lake would stop flowing while the lake filled. Surely these things would be noticed?

Just to give you an idea - they arrived in the area after incredible difficulties, find about 15 square kilometers of burned destroyed and generally torn up forest. They basically work out the epicenter and began compiling data from there.

They assumed if there was anything to find, the obvious place is at the center of the destruction, which is a bog, the assumption being the lack of crater being caused by the soft marshiness of the soil

However to your point of ejecta. I completely agree. This lake is nearly as big as Barringer Crater, there is no way its creation in 1908 would have gone unnoticed, even if the first expedition never went down there, subsequent teams have been all over it

[BenBurch]

You mean that if Lake Baikal consisted of some other liquid, like mercury or sulphuric acid, the stricken water-cooled nuclear reactor-powered alien spacecraft wouldn't have been heading in that direction? I'm sure you're right. It would probably have set a course for Lake Ladoga in that case.

No, I mean water as a coolant for a starship isn't out of the question at all.

It has good properties.

And if you want to convert heat to mechanical effort, you pretty much have to be using a stirling engine rather than turbines if you use a molten metal and that has power density issues.

[davefoc]

Just to give you an idea - they arrived in the area after incredible difficulties, find about 15 square kilometers of burned destroyed and generally torn up forest. They basically work out the epicenter and began compiling data from there.

They assumed if there was anything to find, the obvious place is at the center of the destruction, which is a bog, the assumption being the lack of crater being caused by the soft marshiness of the soil

However to your point of ejecta. I completely agree. This lake is nearly as big as Barringer Crater, there is no way its creation in 1908 would have gone unnoticed, even if the first expedition never went down there, subsequent teams have been all over it

I considered the ejecta issue and I don't think it is a strong argument against the theory that this lake was caused by a chunk of the TCB (Tunguska Cosmic Body). The ejecta may have consisted of mostly soft material that would have been quickly washed away in the area. There were no aerial surveys available in the early expeditions and movement in this area would be extremely difficult so the idea that every patch of the blast area was carefully studied by the early expeditions seems wrong to me. I have never been to this area but I have a notion that it is something like the dense forests of the Pacific Northwest and travel through this area without trails or roads would be extremely difficult. The ground is a jumble of decaying trees and moss and soft ejecta in this kind of terrain would be hard to find after even a year or so.

[Craig B]

No, I mean water as a coolant for a starship isn't out of the question at all.

It has good properties.

And if you want to convert heat to mechanical effort, you pretty much have to be using a stirling engine rather than turbines if you use a molten metal and that has power density issues. I had always thought that starship propulsion, if it ever becomes feasible at all, was far removed from nuclear reactors, leaky or not - let alone Stirling engines.

[davefoc]

I had always thought that starship propulsion, if it ever becomes feasible at all, was far removed from nuclear reactors, leaky or not - let alone Stirling engines.

After the crashed star ship theory discussion is done are going to move on to the Tesla Wardenclyffe Tower theory? That is not to denigrate the star ship theory I think the idea that they were on their way to Lake Baikal to get fresh water for their nuclear generators is completely plausible. But then again it could be that they were collecting biological samples and they were particularly interested in the Baikal fresh water seals.

[BenBurch]

I had always thought that starship propulsion, if it ever becomes feasible at all, was far removed from nuclear reactors, leaky or not - let alone Stirling engines.

You make heat with a nuclear reaction, and you then need to make that into electrical energy. You can use thermopiles or nuclear-voltaic accumulators, but with terrible efficiency and a lot of waste heat. Or you can use a very efficient compound steam turbine at around 40% efficiency or a less-compact and more efficient Stirling at near the maximum Carnot cycle efficiency of whatever the temperature difference is. Or you combine them and use the Stirling in a scavenging role.

It would be nice to have a Mr. Fusion and a flux capacitor, but I don't see that in the cards...

[BenBurch]

After the crashed star ship theory discussion is done are going to move on to the Tesla Wardenclyffe Tower theory? That is not to denigrate the star ship theory I think the idea that they were on their way to Lake Baikal to get fresh water for their nuclear generators is completely plausible. But then again it could be that they were collecting biological samples and they were particularly interested in the Baikal fresh water seals.


Plenty of water around not under a thick atmosphere in a deep gravity well.

Aliens would know about cold traps and would visit the Moon, or go to a comet or Mars or Saturn's rings et al.

[davefoc]

Plenty of water around not under a thick atmosphere in a deep gravity well.

Aliens would know about cold traps and would visit the Moon, or go to a comet or Mars or Saturn's rings et al.

Does this mean that you are skeptical of alien-spacecraft-searching-for-water-in-Lake-Baikal theory but you are open to the alien-spacecraft-on-mission-to-collect-fresh-water-seal-specimen-from-Lake-Baikal theory?

[davefoc]

remove repeated post.

[BenBurch]

Does this mean that you are skeptical of alien-spacecraft-searching-for-water-in-Lake-Baikal theory but you are open to the alien-spacecraft-on-mission-to-collect-fresh-water-seal-specimen-from-Lake-Baikal theory?

No, I think it was probably an icy asteroid.

I was just saying that water was not an impossible coolant choice. Purely an engineering comment.

[davefoc]

No, I think it was probably an icy asteroid.

I was just saying that water was not an impossible coolant choice. Purely an engineering comment.

Sorry to be confused on that point. Good to know though, that alien space voyagers can fill up their nuclear reactor coolant tanks on the moon without needing to raid the earth's fresh water reserves. This might explain why there are so few extra terrestrial space craft crashing about on the earth searching for water to use in their nuclear reactors.

Lake Baikal trivia:
20% of the unfrozen fresh water on earth is in Lake Baikal. It is clearly the place to head if one has a space craft that needs 5700 cubic miles of fresh water or so and one doesn't want to waste a lot of energy melting the polar ice to get it.

[The Man]

I believe the Italians have found nothing - from what little of their paper is accessible on line I just don't see what they have done differently to justify their findings

I dont feel comfortable trying to identify the origins of the lake as it is an area I have had no real interest in.

I do however hope I am wrong - Finding a piece of this beastie would help solve a lot of questions, but if my belief in the comet theory is correct, nobody is ever going to find much of anything


The latter would be my inclination as well and given that such impacts are often concealed by weathering they may actually find something. However it’s tying it to the Tunguska event that’s then going to be the problem.

[MG1962]

The latter would be my inclination as well and given that such impacts are often concealed by weathering they may actually find something. However it’s tying it to the Tunguska event that’s then going to be the problem.

The only thing that troubles me is the knowledge that causality between meteors and craters was not proven in 1961 - Whereas the later Italians would have approached the issue with a very different mind set

[Craig B]

The only thing that troubles me is the knowledge that causality between meteors and craters was not proven in 1961 ... Not in general terms, butThe expedition, led by Leonid Kulik [in 1927], expected to find a meteorite crater and hoped to locate fragments to collect and study. http://www.essortment.com/tunguska-explosion-21562.html so in this case the association between the observed super-"meteor" and a possible crater was made from an early date.

[pakeha]

I've been following the thread and wondered- have they reported finding 'shocked' quartz in the area?

[jenkoul]

I've been following the thread and wondered- have they reported finding 'shocked' quartz in the area?

Not shocked quartz, but would you believe -- micro-diamonds? See: Hough et al., "Chemically Robust Carbon Particles in Peat from the Tunguska Impact Site," (I'd give you the URL, but not till I've done 14 more posts).

Note, however: that "the C[arbon] particles do not have an extraterrestrial signature" [op. cit.]. In other words, they might have been formed from terrestrial material "by a plasma process within the fireball," but give no indication in and of themselves as to what caused the fireball in the first place.

Me, I'm still going with Jackson and Ryan's micro-black hole hypothesis (see the free "Singularity Files" ebook available for Kindle, Nook, and iBooks -- that bloody URL-block again).

Excelsior!
Jenkoul

[jenkoul]

Not in general terms, but [forbidden URL] ... so in this case the association between the observed super-"meteor" and a possible crater was made from an early date.

Kulik, a mineralogist, was well aware of the excavations done in the early years of the 20th century at Great Barringer Crater in Arizona (a.k.a. Meteor Crater -- you know, where they filmed the finale of "Starman") in search of precious metals. He hoped to find a similar treasure trove in the Podkamennaya Tunguska Basin -- meaning, he was definitely looking for a crater. (see Roy Gallant, "The Day the Sky Split Apart," Atheneum, 1995.)

Not that he found one ...
Jenkoul

[jenkoul]

[QUOTE=esquel;8309604]RE: the 'tiny metal spheroids' -- can you point me to a scholarly article on the recovery of same? My Google-fu only comes up with they usual crank sites, and unrelated articles about meteorite recovery.

Try: E. L. Krinov, "Giant Meteorites," Permagon 1966 -- he's got pictures of the micro-spherules.

Jenkoul

[jenkoul]

[QUOTE=MG1962;8309392]Unfortunately Arthur borrowed that idea from a Russian "Alexander Kazantev" who's Wiki entry really doesn't do him justice. He is a very well regarded engineer who in 1945 put the nuclear accident idea together, which was extremely influential for the next twenty years in Tunguska research.

Interestingly, Kazantsev was a member of the Soviet observer team sent to Hiroshima at the end of the Second World War. It was there that he saw how buildings and trees directly at the epicenter were still standing. It was that resemblance to Kulik's "telegraph pole" forest that first got him thinking in terms of Tunguska as atomic air burst.

More on this in "The Singularity Files," a free Kindle/Nook/iBooks ebook.

[jenkoul]

But didn't the first explorers of the area find a tree pattern with a central group still erect, stripped of leaves and bark, and millions of others felled pointing away from this central area, indicating an air burst above an identified location in the forest?

Yes, this is Kulik's well-known "telegraph pole" grove, which he described as "dead forests enchanted as if in a fairy tale." (Roy Gallant, The Day the Sky Split Apart, Atheneum, 1995, p. 78.) Gallant reports many of those trees were still standing, stripped of leaves and bark, in 1992.

[jenkoul]

15 years later. That's a long time.

Actually, 19 years later (Kulik's first expedition was in 1927). Understandable, though -- between World War I, two 1917 Revolutions, and a Civil War, Soviet Russia had other things on its mind back then.

[jenkoul]

Does anybody know if the Czar's maps of this area are available online anywhere? This was hellishly remote, and I wonder what level of detail we might expect?

The answer seems to be: not a whole lot. At the turn of the twentieth century there were fewer than thirty thousand men, women, and children throughout the entire 300,000 square mile Stoney Tunguska Basin -- not a whole lot of detailed cartography needed.

OTOH, there are some indications, by Lyuchetkan inter alia, in Vasiliyev's 1981 collection of eyewitness accounts (I'd give you a URL for the Russian original if I had enough posts) that there *was* a lake there prior to 1908. This whole issue is considered, with a somewhat jaundiced eye, in Bill DeSmedt's "The Singularity Files" (Seminar 4: The Lake Cheko 'Crater: Hoax or Fraud?) free for Kindle, Nook, iBooks (but again, can't give you the URL).

Jenkoul

[jenkoul]

Right. I remember seeing it from above, so the one in the video is not the same as the experiment that I recall. The program I saw definitely showed a butterfly pattern, in very good light.

FWIW, here's a description (from Bill DeSmedt's "The Singularity Files") of the original experiment:
"In nineteen sixty-five, Igor Zotkin took that germ of an idea and tested it, best he could: By comparison with the computer simulation technology we can throw at the problem nowadays, Zotkin’s experiment was dirt-simple, almost painfully so — but it worked. He built a scale model of the taiga using matchsticks for pine trees, strung a wire over it and then flew a lit firecracker down that wire. Kept varying the wire-guided trajectory, in an attempt to reproduce the pattern of the Tunguska treefall. His first time out, all Zotkin succeeded in doing was blowing his model to bits. But, after a little tinkering with the angle of approach and such, his aerial mini-explosions were duplicating the distinctive 'butterfly' pattern that other researchers had mapped out at the blast site during the fifties."

[jenkoul]

There were no maps - The lake is actually nearly 5 miles from the impact zone. It was only during the 1958 expedition the lakes origins was considered. However the 1961 trip pretty much argued the lake was much older than 1908 - Disputing this seems to be one of the cornerstones of the Italian research

Here's K. P. Florenskii's findings from the 1961 expedition:
"Silt specimens from Lake Cheko and the lake in the bend of the River in the west morass were collected for subsequent stratigraphic study (P.N. Paley et al.) with a grab dredge and a swamp drill designed by N.I. P’yavchenko. The various samplings from the bottom of Lake Cheko revealed extensive development of silt up to 7 meters deep, indicating an ancient origin for the lake (tentatively estimat-ed at 5,000 to 10,000 years), thus completely contradicting the hypothesis of the formation of the lake as a result of the Tunguska meteorite fall."

... kind of hard to explain away.

[jenkoul]

jenkoul: Tiny black holes

Not even worth a look IMHO. Some kind of extraterrestrial impact object has been proven from my point of view and the micro black hole theory has been disproved.

.

Actually, the "disproof" in question consisted in:

1. The Burns, Greenstein, Verosub Royal Astronomical Society paper retrodicting some hard-to-miss effects if the BH impactor had weighed in at the 10E23g Jackson and Ryan had assumed, and

2. The real killer -- Beasley & Tinsley's Nature note pointing out the absence in the meteorological records of any trace of the "exit event" Jackson & Ryan had predicted.

In retrospect, given the nascent state of primordial BH theory back in the mid-seventies (Hawking's seminal paper was itself only published in 1973), it's not surprising that J&R assumed a PBH of asteroidal mass. Being unaware of BH radiation (Hawking, "Particle Creation by Black Holes," 1975), they thought they needed to account for all the Tunguska phenomena by means of gravitational effects alone.

Things start to look different once Bekenstein-Hawking radiation is factored in, not to mention black monopoles.

[MG1962]

Here is the URLs for the book jenkoul mentioned earlier in the thread but was unable to post links too


Regardless, the "Singularity Files" URLs are:
* Kindle
(http://www.amazon.com/Singularity-Audiobook-Seminars-Sequence-ebook/dp/B0080JGVPG/),
* Nook
(http://www.barnesandnoble.com/w/the-singularity-files-bill-desmedt/1110613193?ean=2940033174393),
and
* iBooks
(http://itunes.apple.com/au/book/singularity-files-audiobook/id515778023?mt=11).

[pakeha]

Thanks for the links!

[Olowkow]

Here is the URLs for the book jenkoul mentioned earlier in the thread but was unable to post links too


Regardless, the "Singularity Files" URLs are:
* Kindle
(http://www.amazon.com/Singularity-Audiobook-Seminars-Sequence-ebook/dp/B0080JGVPG/),
* Nook
(http://www.barnesandnoble.com/w/the-singularity-files-bill-desmedt/1110613193?ean=2940033174393),
and
* iBooks
(http://itunes.apple.com/au/book/singularity-files-audiobook/id515778023?mt=11).

I got it a while back, and I'm almost finished reading the book. I expected a lot less, but it turns out to be an informative and fun read....and free.

[jenkoul]

Interesting article published yesterday in a Russian journal (Ogoniok) describing additional claims by Team Bologna. I'd include the URL, but ...

[DavidS]

Interesting article published yesterday in a Russian journal (Ogoniok) describing additional claims by Team Bologna. I'd include the URL, but ...
If your "but..." refers to your inability to post links due to low post count, you could always translate the URL to one of several HRRL formats (Human Readable Resource Locator), e.g.:

Forum software recognizes URL form as a link...
www.google.com (http://www.google.com)

...but it has a hard time telling HRRL from ordinary text:
www . google . com
www dot google dot com

It's sorta like cheating the auto-censor to post profanity, but more acceptable because the effect is closer to the spirit of the rule.

[Belz...]

http://m.phys.org/news/2012-05-team-evidence-lake-cheko-impact.html



I fished out a Google Earth image of it (attached) - yes that looks like it might be an astrobleme!

From my understanding the lake had been there for a while before the incident, and it's not at ground zero, though I suppose it could be a smaller chunk of the impactor.

[Belz...]

One other possibility; The lake is an astrobleme but much older than Tunguska.

http://forums.randi.org/imagehosting/thum_60804fe34a4d73ec4.jpg (http://forums.randi.org/vbimghost.php?do=displayimg&imgid=26415)

[Craig B]

From my understanding the lake had been there for a while before the incident, and it's not at ground zero, though I suppose it could be a smaller chunk of the impactor. But at ground zero there is no chunk of the impactor, so a "smaller chunk", than no chunk at all, produces a bigger impact effect?

[Belz...]

One of the implications of the tiny black hole theory is, of course, that the TBH travelled straight through the earth and created a similar disturbance at its exit point, say, antipodeal to the Tunguska region where it originally impacted. I have read discussion of this possibility. We're looking for a catastrophe a millisecond after the Tunguska event, but in the southern hemisphere. Any candidates?

Wouldn't it also cause damage in the intervening volume, cutting a rather large wormhole into the Earth ?

[Belz...]

But at ground zero there is no chunk of the impactor, so a "smaller chunk", than no chunk at all, produces a bigger impact effect?

The impactor detonated above ground. If the whole thing fell and made the lake then it's damn weird considering the destruction pattern.

[Craig B]

Wouldn't it also cause damage in the intervening volume, cutting a rather large wormhole into the Earth ? Oh dear God, there's new stuff on this, about black holes evaporating on their way through the planet by means of Hawking radiation and things like that, which completely do your head in. So I've no idea. It has entered the realm of metaphysics.

[davefoc]

But at ground zero there is no chunk of the impactor, so a "smaller chunk", than no chunk at all, produces a bigger impact effect?

I don't know how good an argument this is. Assume an object principally made up of material that was vaporized but with a more solid bit mixed in. Is there any particular reason to suspect the solid bit would have been at the center of gravity for the overall object? If it is just a bit outside the center of gravity the explosion is going to propel it away from the center.

Still, I was leaning to the idea that the Italians might be on to something, but it seems the tide is running against them in this thread and my lack of knowledge about all this allows my view to be easily swayed so I've moved back to my original view which leaned against the Italians.

[Belz...]

Oh dear God, there's new stuff on this, about black holes evaporating on their way through the planet by means of Hawking radiation and things like that, which completely do your head in. So I've no idea. It has entered the realm of metaphysics.

Ok if it evaporates, but if there's a corresponding explosion on the other side of the planet, there would be damage in between, unless I'm misunderstanding.

Why are we talking about black holes and spaceships in a thread discussing lake Cheko ?

[MG1962]

Ok if it evaporates, but if there's a corresponding explosion on the other side of the planet, there would be damage in between, unless I'm misunderstanding.

Why are we talking about black holes and spaceships in a thread discussing lake Cheko ?

Tunguska

[Belz...]

Still, maybe we should focus on the non-crazy hypotheses.

[MG1962]

Still, maybe we should focus on the non-crazy hypotheses.

Trouble is the non crazy theories wont interest people. Why accept the mundane when there are all these exotic concepts to deal with

[Belz...]

Trouble is the non crazy theories wont interest people.

Ah, yes. The Fox news theory of debating. ;)

[MG1962]

Ah, yes. The Fox news theory of debating. ;)

I guess fun is where you find it. Personally I dont need mini black holes or UFOs to make the events at Tunguska fascinating.

But then again I think many of the things that interest me would leave many bored out of their brains

[jenkoul]

If your "but..." refers to your inability to post links due to low post count, you could always translate the URL to one of several HRRL formats (Human Readable Resource Locator), e.g.:

Forum software recognizes URL form as a link...

...but it has a hard time telling HRRL from ordinary text:
www . google . com
www dot google dot com

It's sorta like cheating the auto-censor to post profanity, but more acceptable because the effect is closer to the spirit of the rule.

Tried, but no joy. However the pub in question is "Russia beyond the headlines," and the domain name is the four-letter abbreviation of that title plus a dot plus the country code for Russia (ru). The name of the article itself is "Scientists uncover evidence in Siberia's century-old meteorite mystery," pub date June 28, 2012. Good luck.

[Olowkow]

This one?

http://rbth.ru/articles/2012/06/28/scientists_uncover_evidence_in_siberias_century-old_meteorite_myster_16012.html

Seems like, bottom line is:

Finally, the Italians’ best card: Professor Michel Pipan at the University of Trieste hired an Mi-26 helicopter in Krasnoyarsk to carry out geomagnetic aerial photography of the lake and its surroundings.

“Right above the middle of the lake, the machine detected a significant magnetic disturbance, i.e., there is a material mass deep under the lake with a strong magnetic field, presumably iron. I am positive that it is our meteorite.”

[Craig B]

Still, maybe we should focus on the non-crazy hypotheses. Agreed! Like the hypothesis that the area was whacked by a lump of frozen volatile material, of which we know an abundance exists in the outer solar system. Alien spaceships with malfunctioning nuclear propulsion units on course for Lake Baykal are to be invoked only after all possible mundane explanations have been refuted. We are far from that situation as yet.

[Belz...]

I guess fun is where you find it. Personally I dont need mini black holes or UFOs to make the events at Tunguska fascinating.

I think a multi-megaton explosion caused by a flaming ball of iced rock falling at crazy speeds towards the earth and narrowly missing areas where it would've killed millions of people is kinda fascinating, too.

[MG1962]

I think a multi-megaton explosion caused by a flaming ball of iced rock falling at crazy speeds towards the earth and narrowly missing areas where it would've killed millions of people is kinda fascinating, too.

Yeah I agree. Personally I am very firmly in the comet theory corner, the whole endless days phenomena across Europe for three days before the actual event points clearly to me we were in a comets tail.

Measurements from the US seem to indicate an air burst at about 10 - 15kms, so if anyone does find a piece of this beastie it would indeed be exciting