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Space Science

Crater From 1908 Tunguska Blast Found 192

Posted by kdawson
from the fire-came-by dept.
MaineCoasts writes "A team of scientists from the Marine Science Institute in Bologna claims to have found the crater left by the aerial blast of a comet or asteroid in 1908 in the Tunguska region of Siberia. The blast flattened 770 square miles (2,000 square kilometers) of forest, but to date no remains or crater have been found. This has left open the question of what kind of object made the impact. The team believes that, contrary to previous studies, nearby Lake Cheko is only one century old and 'If the body was an asteroid, a surviving fragment may be buried beneath the lake. If it was a comet, its chemical signature should be found in the deepest layers of sediments.' The team's findings are based on a 1999 expedition to Tunguska and appeared in the August issue of the journal Terra Nova."
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Crater From 1908 Tunguska Blast Found

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  • by Dunbal (464142) on Thursday November 08, 2007 @09:22AM (#21280745)
    I remember reading about this as a kid, probably introduced to it by Carl Sagan in his "Cosmos" series.

    At the time I wondered, after seeing all those flattened trees, how they failed to find the crater. Wouldn't it just be a case of going to several spots, drawing a parallel line to the flattened trees, then looking on a map for the point where the lines intersect? Presumably all the trees fell "away" from the blast area.
    • by $RANDOMLUSER (804576) on Thursday November 08, 2007 @09:25AM (#21280779)
      Canventional theory (and TFA) suggest that the explosion was an air-burst about 6 miles above the ground. So the "center" of the blast region is still pretty large.
    • by eldavojohn (898314) * <eldavojohn AT gmail DOT com> on Thursday November 08, 2007 @09:27AM (#21280797) Journal

      At the time I wondered, after seeing all those flattened trees, how they failed to find the crater. Wouldn't it just be a case of going to several spots, drawing a parallel line to the flattened trees, then looking on a map for the point where the lines intersect? Presumably all the trees fell "away" from the blast area.
      No, the explosion was above ground level, see our prior discussion on this [slashdot.org].

      Also, my post on this [slashdot.org] has a link to a PDF with a sketch of the breaking apart and trajectories.

      Also, remember how long ago this happened. There was an expedition there but they didn't have the technology we did. I'm not sure if the tree patterns would help you 100 years later.
      • by iamlucky13 (795185) on Thursday November 08, 2007 @01:45PM (#21284321)

        Also, remember how long ago this happened. There was an expedition there but they didn't have the technology we did. I'm not sure if the tree patterns would help you 100 years later.

        Yes. Something that is easy for us to forget is that they didn't have roads, or even much in the way of all terrain vehicles, much less helicopters or satellites when this occurred. Not to mention, it was largely ignored until after the revolution and WWI were both finished up with. The first aerial photographs taken of the site were taken 30 years later and still clearly showed the fall pattern, but no crater was visible.

        It's easy to look at the pictures and think you can simply follow the trees all the way to the center. Way easier said than done. First of all, the site is pretty much in the middle of nowhere. There's just a few scattered villages, no doubt with abysmal roads between each and almost nothing traversable with wheels leading anywhere else. They would have walked or ridden pack animals for the entire survey.

        It's also a huge area. 80 million trees were felled over 830 square miles. Hunters (I've done my share) and loggers are probably familiar with trying to walk through such an area. The trees may look all neatly arrayed in a photograph, as if you could step easily from one to the next or walk between them like a trail, but the truth is far different. Without the perspective benefit from being atop a hill, the fall pattern is more difficult to discern. The branches will lie tangled, blocking the path at frequent intervals. The trunks will be random distances apart, some managing to overlap nearby trunks. They often sit several feet above the ground, making it easy to fall and twist an ankle or knee, and exhausting to climb over again and again and again. Vegetation will have sprouted up in the 19 years between the fall and Kulik's arrival, leaving a tangled mess of shrubs and briers that sometimes appear deceptively solid from above and forboding from ground level. A mile per hour is a decent speed walking through such an area with several days worth of supplies on your back.

        But Kulik actually did push through to the center, and he found several trees standing upright, stripped of their branches, consistent with an airburst from above. He also found a bog he was convinced was a crater, but when he drained it there were old tree stumps at the bottom. For an impact to have formed the bog the blast would have shattered the old trees and tossed the remains out of the muddy crater.

      • by RockDoctor (15477)

        Also, remember how long ago this happened. There was an expedition there but they didn't have the technology we did. I'm not sure if the tree patterns would help you 100 years later.

        The first expedition to the area of "ground zero" got there approximately 20 years after the event. They were guided by local memories and reports of the fireball (which they had to triangulate) ; they had reports form some local hunters that "there were flattened trees three valleys over thattaway ...", etc. And, of course, th

    • Airburst (Score:5, Informative)

      by wiredog (43288) on Thursday November 08, 2007 @09:27AM (#21280805) Journal
      An airburst wouldn't leave a crater. Drawing lines would lead to the hypocenter, directly under the burst.
      • An airburst should leave multiple craters. After all, the pieces have to go someplace. Whether or not we can find those smaller craters after a century is another issue...
        • by Amouth (879122)
          not always.. rememeber that while Metor Crator in the US - it is belived that the metor completely vaporized before impact and that the impact was the force ofthe gass hitting - so if it was at the right angle and the above ground explosion vaporized the material. the whole landscape wouldahve been the crator - whichthe trees would have obsorbed.. meaning no visable crator..
          • Regarding Meteor Crater, I recall seeing good sized chunks of mostly Iron-Nickel displayed in the MC museum that had been recovered from the bottom center of the crater. Not gas samples; mostly-iron-nickel rock. However, your point is well taken: Consider the debris field from the shuttle explosion; now bring it a bit closer to the ground. You are still talking about a massive debris field and as you pointed out, an impact footprint so large and dissipated that perhaps the downed trees *are* the crater..
        • Re:Airburst (Score:4, Informative)

          by SETIGuy (33768) on Thursday November 08, 2007 @06:09PM (#21287845) Homepage

          An airburst should leave multiple craters. After all, the pieces have to go someplace. Whether or not we can find those smaller craters after a century is another issue...
          It did go somewhere. You're breathing it now.

          I think you may have a misconception as to why an airburst occurs. A meteor (or comet) enters the atmosphere and is decelerated by interacting with the air. To first order the rate of deceleration (and therefore the stress on the meteor) is related to the ratio of the surface area of the object to its mass. If the deceleration stress exceeds the tensile strength of the material it will fragment. If you break an object into multiple pieces, you've increased the surface area but left the total mass the same. The net effect that fragmenting increases the stress and results in more fragmentation and more rapid deceleration. Once fragmentation starts it doesn't like to stop. It progresses very rapidly and all of the kinetic energy gets turned into heat in a few microseconds.

          Another way of thinking about it is that it would be hard to get solid pieces surviving after a 15 megaton airburst. Pick your favorite 60 meter diameter piece of rock. Put a 15 Mton H-bomb on it and set if off. Tell me home much of your rock is left.

          • by Cadallin (863437)
            Depends on what the rock is made of. During research for project Orion, http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) [wikipedia.org], They found that you could coat a specially designed metal plate in graphite based lubricant and it would survive repeated nuclear blasts with occasional reapplication of the lubricant. Also noted in the linked article was that during the Castle Bravo Nuclear test graphite coated steel spheres were placed at a nuclear test site and recovered afterwards intact, so it is ce
      • Re:Airburst (Score:5, Interesting)

        by ChrisA90278 (905188) on Thursday November 08, 2007 @11:49AM (#21282543)
        It might have been multiple air bursts if the comet broke up first. Then you would have a fairly complex pattern. Likely not as simple as the ideal case there a point source blast all goes off at once. The chunk of ice was moving fast and exploded over a period of time. So the blast came from not a point but a few short line segments
      • by Khyber (864651)
        And just like a grenade exploding in the air above the ground, comet fragments would be driven into the ground below for pickup and discovery. Drawing lines would work out reasonably well, as the center of the blast location would be ideal for finding trace remnants of the comet.
    • by FredDC (1048502) on Thursday November 08, 2007 @09:29AM (#21280825)
      In theory yes, but you have to know that this is a very remote and large area. And they didn't have the technology we have available now.

      Right now we'd simply take some pictures with a satelite, and fly some helicopters to the impact spot. Back then they would've had to mount an expedition on foot. And that was simply not feasible.

      By the time it became possible to reach the impact site relatively easy, nature had already taken its course and finding the impact spot became impossible/very hard.
      • by larpon (974081) on Thursday November 08, 2007 @09:50AM (#21281071)
        This picture was taken over the crater in Siberia with an onboard polaroid during the
        Apollo 11 mission...

           \ | /
          -  O  -
           / | \

        It reminds me of something...
    • by AikonMGB (1013995) on Thursday November 08, 2007 @09:31AM (#21280843) Homepage

      From what I know of the event, and as is stated in the summary, it was an aerial blast; i.e. the asteroid/comet/alien-spaceship exploded before impact. The "crater" where the remains of the $object should be found would not be directly under that explosion, as the $object would have some unknown velocity at some unknown angle.

      While the method you propose makes sense, all it really tells you is where the explosion occured, not where the remains can be found.

      Aikon-

      • it was an aerial blast; i.e. the asteroid/comet/alien-spaceship exploded before impact.

        Well there you have it, Dennis Kucinich must have been there so all we need to do is ask him!
      • by davidsyes (765062)
        Since we have spaceships brought up, maybe Tunguska crater was the "free end" of a wormhole wagging its tail? Several "annular centers" might exist? Like crater face?
    • by Osurak (1013927) on Thursday November 08, 2007 @10:14AM (#21281329)
      Dr Ray Stantz: Are you okay?
      Louis: Who are you guys?
      Dr Ray Stantz: We're the Ghostbusters.
      Louis: Who does your taxes?
      Dr Ray Stantz: You know, Mr. Tully, you are a most fortunate individual.
      Louis: I know!
      Dr Ray Stantz: You have been a participant in the biggest interdimensional cross rip since the Tunguska blast of 1909!
      Louis: Felt great.
      Dr. Egon Spengler: We'd like to get a sample of your brain tissue.
      Louis: Okay.
    • by mikael (484) on Thursday November 08, 2007 @12:07PM (#21282819)
      The trees that were directly below the air explosion were still upright. The trees at some distance were flattened. A large explosion all around Europe was heard on that night, along with a glow in the sky. But it took several months for the expedition to find out what had caused the explosion/light. By that time, the crater would have filled with water and appeared to be a lake to the expedition team.

      If it had been a loosely packed asteroid or a comet, it would have disintegrated into lots of small chunks and vaporised before reaching the ground.

      The eyewitness reports are interesting:

      "Kezhemskoe village. On the 17th an unusual atmospheric event was observed. At 7:43 the noise akin to a strong wind was heard. Immediately afterwards a horrific thump sounded, followed by an earthquake which literally shook the buildings, as if they were hit by a large log or a heavy rock. The first thump was followed by a second, and then a third.

      We have friends who own a house next to quarry. Whenever there is a major explosion there always seems to two explosions heard; the first seems to be the shockwave travelling through the ground (a large dull sound thump) while the second is the shockwave through the air which sounds like a shotgun being fired. Then there is the all clear. So maybe the lake is the crater.
  • by SpaceLifeForm (228190) on Thursday November 08, 2007 @09:24AM (#21280765)
    With the lake being the melted ice of the comet.
    • Re: (Score:3, Insightful)

      by MBGMorden (803437)
      Imagine how much extra the bottled water industry could charge for THAT.

      "This water came from ice that sustained a comet 4.6 billion years. Don't you deserve the same? Buy Samethingastheothers Water. It's out of this world!"

  • If scientists can't find a crater that's 2,000 square miles across then what chance do they have the day they lose their keys down the back of the sofa?
    • by MarkGriz (520778) on Thursday November 08, 2007 @09:33AM (#21280877)
      "If scientists can't find a crater that's 2,000 square miles across then what chance do they have the day they lose their keys down the back of the sofa?"

      Considering YOU think that square miles are a measure of distance rather than area, and that kilometers are equivalent to miles, I'd say they have a better chance than you do.
  • by circletimessquare (444983) <<moc.liamg> <ta> <erauqssemitelcric>> on Thursday November 08, 2007 @09:26AM (#21280791) Homepage Journal
    the impact site is 3.26 km wide. this corresponds to a resonance chamber for the tau muon rays we are all familiar with, with a frequency of 23.44 kHz. please adjust your tin foil hats accordingly
    • Re: (Score:3, Funny)

      by simcop2387 (703011)
      HE'S FEEDING US FALSE INFORMATION!
      he's trying to get us to retune our hats to let in the REAL frequency!

      the speed of light / (3.26 kilometers) = 91.9608767 kilohertz
      • where does your propaganda come from?

        people can't even get the speed of tau muon rays right? they come straight from the golden orifice of ga-ur! who in their right mind would not possess this information? it should be memorized by schoolchildren

        egads

        WE HAVE BEEN INFILTRATED BY THE PULAXI, SPREADING THEIR USUAL LIES

        trust no one and nothing
  • Phooey! (Score:2, Funny)

    by Dan East (318230)
    A team of scientists from the Marine Science Institute in Bologna claims to have found the crater left by the aerial blast of a comet or asteroid in 1908 in the Tunguska region of Siberia.

    This is nothing but a bunch of bologna.

    Dan East
  • Tesla connection? (Score:4, Interesting)

    by sobolwolf (1084585) on Thursday November 08, 2007 @09:57AM (#21281139) Journal
    I watched a google movie about Nikola Tesla the other night and there was speculation that the blast may have had something to do with the "death ray" that he was fooling around with at the time.

    Tesla built his "death ray" at Wardencliffe on Long Island, and it is a possible that he tested it one night in 1908. The story goes something like this. At the time, Robert Peary was trekking to the North Pole and Tesla asked him to look out for unusual activity. On the evening of 30 June 1908, Tesla aimed his death ray towards the Arctic and turned it on. Tesla then watched the newspapers and sent telegrams to Peary, but heard about nothing unusual in the Arctic.

    However, he did hear about the unexplainable event in Tunguska, and was thankful no one was killed, as it was clear to him that his death ray had overshot. He then dismantled his machine, as he felt it was too dangerous to keep it.
    Mad Scientists FTW!!!!!
    • by Black Parrot (19622) on Thursday November 08, 2007 @11:11AM (#21282027)

      I watched a google movie about Nikola Tesla the other night and there was speculation that the blast may have had something to do with the "death ray" that he was fooling around with at the time.
      And of course, everything you hear about Tesla is true.

      Tesla built his "death ray" at Wardencliffe on Long Island, and it is a possible that he tested it one night in 1908.
      Who can argue with unsourced speculation like that?

    • by kamapuaa (555446)
      Awesome, very informative post. While we're at it, I heard that the cold summer of 1816 was caused by Benjamin Franklin's nature-tampering experiments with electricity. [ijpr.org]
      • With all respect for Franklin, but if there's one man who could have really done it, it is Tesla. http://www.pbs.org/tesla/ll/ll_colspr.html [pbs.org]
        • by davidsyes (765062)
          Anyone remember the jingle: "BALL Park FRANKS... They PLUMP when you cook'em.. BOOM-BOOM-BOOM"?

          I guess if Franklin dicked around with a Tesla coil (were he around to do so) his franks would have plumped and boomed like shot heard round the whirled. He'd need an alchemist to cures that woe and ail..
    • by lahvak (69490)
      However, he did hear about the unexplainable event in Tunguska, and was thankful no one was killed, as it was clear to him that his death ray had overshot. He then dismantled his machine, as he felt it was too dangerous to keep it.

      It didn't overshoot. Superman happened to be flying by, and he saw that the ray would cause the Arctic ice to melt, thus causing massive flooding, so with one mighty punch, he deflected it to Siberia, where it did relatively minor damage.
    • by davidsyes (765062)
      That explosion was a rift in the fabric of the space-time continuum, caused by that one Ken Starling-- a Santa Cruz's beach boardwaklin', pot-smoking, industrialist, con, investor, and wannabe space traveler, trying to shoot down these threads, but he set to the wrong era and instead shot down a temporally displaced crater that intersected the Earth and another Earth.

      He was also trying to ensure the installation of that being in the ovulum orifice in DC, that Vidiian, wraped in Kazon skin, cocooned by Talos
    • by dbIII (701233)
      That has a few problems - not least the honesty of Robert Peary and where he actually went.
  • Googlink (Score:5, Informative)

    by PhilHibbs (4537) <snarks@gmail.com> on Thursday November 08, 2007 @09:58AM (#21281153) Homepage Journal
    Google map [google.co.uk] of the point that the National Geographic map link goes to
  • by Joaz Banbeck (1105839) on Thursday November 08, 2007 @10:11AM (#21281299)
    From a 1960 interview with a witness, he refers to the existence of lake Cheko prior to the event:

    In that place the seven rich Dzhenkoul brothers in those days pastured a reindeer herd of 600-700 head. The brothers were rich. On that day, [my] father went to meet the reindeer on the Ilimpo [river] (in the north). The herd was pastured between the Kimchu river and the Polnoty (Churgim) river. On the upper reaches of the Polnoty river there was a storehouse. There was a second storehouse at the mouth of the Cheko...
    More at: http://www.vurdalak.com/tunguska/witness/dzhenkoul_l.htm [vurdalak.com]
    • by EnderGT (916132) <endergt2k@@@verizon...net> on Thursday November 08, 2007 @11:21AM (#21282163)
      Something to remember about that "witness account":

      L. V. Dzhenkoul was born in 1904, so his personal memories of the 1908 Tunguska Event are minimal. Here he is recounting what he was told by his father V[asilii?] I[l'ich] Dzhenkoul and uncle I[van] I[l'ich] Dzhenkoul (both long dead by the time of Kolobkova's 1960 interview.

      It seems highly likely to me that this individual is using "the mouth of the Cheko" as a landmark that is known to him, and is not necessarily indicating that this feature was present prior to the incident.

    • by Blakey Rat (99501)
      Two points here:

      1) If he's using the lake's location as a reference point, he could very well say something occured "near Lake Chako" in 1960, even if that lake didn't exist in 1908. For instance, I can say that gold mining occurred in the late 19th century near Mill Creek in Washington State, that doesn't imply that the city of Mill Creek existed in the 19th century.

      2) Even if the lake did exist, it's not entirely unrealistic to think that the remains of the comet/meteor/whatever could be in the lake, is i
    • by tjw (27390) on Thursday November 08, 2007 @02:13PM (#21284699) Homepage

      In that place the seven rich Dzhenkoul brothers in those days pastured a reindeer herd of 600-700 head. The brothers were rich.
      1) how is the brothers' wealth relevant to this story in any way?
      2) how rich were they?
  • by Paul Jakma (2677) <paul+slashdot@jakma.org> on Thursday November 08, 2007 @10:22AM (#21281403) Homepage Journal
    Uni of Bologna have a site on Tunguska [bo.infn.it], including a whole section on this new, possible crater [bo.infn.it] - with pictures.
    • Re: (Score:2, Informative)

      by kc8jhs (746030)
      Google maps view [google.co.uk] of the area equivalent to this map from the Univeristy site.
    • Thanks for the links, but the horrible multi-color flashing NEW from sometime in the mid '90s just kills the credibility for me. It also makes me want to gouge my eyes out, but that's a different type of crater.
    • by brjndr (313083)
      How much can you trust info from the University of Bologna?
  • by Random BedHead Ed (602081) on Thursday November 08, 2007 @11:05AM (#21281915) Homepage Journal

    In Soviet Russia, asteroid finds you.

    (Bracing for mod down ...)

  • Gasperini claims this is a new discovery, and yet in 2001 he was publishing papers indicating this belief. I think he's exaggerating when he says "we didn't have a clue that Lake Cheko might fill a crater" before finding this latest evidence.

    Either that, or National Geographic is misrepresenting his Gasperini's quotes to make a story where there isn't one.
  • by Sara Chan (138144) on Thursday November 08, 2007 @12:27PM (#21283081)
    The hypothesis that the blast was due to a comet/asteroid/etc. has been around for a long time. The problem with this hypothesis is that it does not fit at all well with the observations (e.g. the strange sounds and lights that preceded the blast for days; and so on). An alternative hypothesis was proposed by Wolfgang Kundt, a researcher at the Institut für Astrophysik der Universität Bonn:

    Kundt W. (2001),
    The 1908 Tunguska catastrophe: An alternative explanation [ernet.in]”,
    Current Science, 81: 399–407.

    Kundt's paper explains the various problems with the comet/asteroid hypothesis. It also proposes an alternative hypothesis: that Tunguska was a natural gas leak (from the ground), that went on for days, building up, until ignited by a lightning strike.

    This explanation seems to fit the observations well. Perhaps the main reason it has not gotten much attention is that it is not very exotic.
    • Not very exotic? Have you heard of anything like this happening before? If anything, the reason it gets no attention is that something similar has never been recored before, while asteroid impacts are pretty common.
  • Unlike humans alien species have been getting shorter over the years. Back when this occured aliens were many times larger and so where their spaceships. If you factor in the ratio of modern day aliens and circles in corn fields and compair it to tree's and the "Comet blast" you will find that the ratio is almost identical.

  • "Looking at photos like these [deputy-dog.com] scares and fascinates me in equal doses".
  • by glwtta (532858)
    So, are they actually claiming this again, or do we just get to read [slashdot.org] about it again?

    Besides, everyone knows Tesla did it, anyway.
  • William Hartmann, senior scientist of the Planetary Science Institute in Tucson, Arizona, said the new findings are compelling but do not address all of the lingering questions about the event.

    This is certainly an understatement. That event is associated with numerous unusual characteristics ...

    The extraordinary power of the high-energy explosion above ground.
    Repeated testimony of strange sounds before the event.
    The glowing of the sky before the event.
    Reports of strange weather before the event.
    Reports of

      • by pln2bz (449850) *
        Tesla was quit enigmatic himself, but I've seen him brought up with the Electric Universe Theorists several times only to receive a blank stare in return. It appears that not all electromagnetic heretics actually learn about Tesla. ;)

        I'm just here trying to raise awareness that there are multiple explanations for the mechanics of the universe. What is enigmatic within one model -- like dark matter or whatever -- makes total sense in another. It's easy to allow oneself to become consumed by History Channe

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