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Space Science

Details Emerging On Tunguska Impact Crater 164

Posted by kdawson
from the closing-in-on-a-big-boom dept.
#space_on_irc.freenode.net (Dusty) writes "Lake Cheko in Siberia has been noted as the probable crater of the 1908 Siberian Tunguska event. This news was discussed here in December, but details on the crater were scant. Now a new paper written by Luca Gasperini, Enrico Bonatti, and Giuseppe Longo (the same team in Bologna, Italy that made news in December) has a horde of new details on the supposed crater. The team visited Lake Cheko complete with their own catamaran and completed ground-penetrating radar maps, side-scanning sonar images, aerial images, and some sample collection of Lake Cheko. Intriguingly, they also imaged an object under the sediment that may be a fragment of the impacting body. Their paper (PDF) includes a lot more details including images, side-scanning sonar image, a 3-D view of the lake, a morphobathymetric map. It's an interesting read, these dudes are good. They plan to return this summer and drill the core if weather permits, hopefully answering the question once and for all." The same team also has a more discursive article in the current Scientific American that includes some detail on the working conditions in the Siberian summer. Think: mosquitos.
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Details Emerging On Tunguska Impact Crater

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  • by Phrogman (80473) on Tuesday May 27, 2008 @01:50PM (#23559075) Homepage
    err, post I mean
    • Go Slashdot !!! (Score:4, Interesting)

      by Anonymous Coward on Tuesday May 27, 2008 @02:16PM (#23559515)
      This is what I'm talking about!

      No more of that crap from idle on the front page, this is what you should be posting! This makes my geekiness tingle, this is what keeps me coming back. Please, for the love of God, more of the same!
  • by Anonymous Coward
    ...thirty-five feet long, weighing approximately six hundred pounds.
  • whoosh... (Score:5, Funny)

    by Thornburg (264444) on Tuesday May 27, 2008 @01:53PM (#23559131)

    BOOOM!!!

    What else do we need to know about the Tunguska event?

    Ok, maybe it would make a cool short film by some of animation whiz. Preferably starring the squirrel from the Ice Age shorts.
    • by NickFortune (613926) on Tuesday May 27, 2008 @02:04PM (#23559327) Homepage Journal

      Seriously, the smart bet seems to be that event was caused by an asteroid strike. But until someone gathers some hard data, that's still only a hypothesis.

      What self respecting scientist wouldn't go and examine the evidence? Because if it wasn't an asteroid strike...

      • by Dancindan84 (1056246) on Tuesday May 27, 2008 @02:40PM (#23559867)

        What self respecting scientist wouldn't go and examine the evidence? Because if it wasn't an asteroid strike...
        ... they may accidentally defrost Megatron!
      • by phat_cartman (1255042) on Tuesday May 27, 2008 @03:31PM (#23560649)

        What self respecting scientist wouldn't go and examine the evidence?

        I initially read that as "What self-replicating scientist...". After that, the jokes really write themselves...
      • Re: (Score:3, Interesting)

        If I remember correctly, most of the models depict an asteroid exploding in mid-air. Certainly, a great deal of the debris would end up on the ground, but falling debris would have a very different impact (no pun intended, unless it's funny) than a single large strike.
      • by Solr_Flare (844465) on Tuesday May 27, 2008 @05:30PM (#23562607)
        Well, there is little doubt by any reputable scientist that it was some form of extra-terrestrial impact, what has remained in contention for a long time was what exactly impacted at Tunguska.

        One side insists it was an Asteroid, but the material that would normally be present at an asteroid impact just isn't there. Others argue it was a comet, but analysis of comets in the last decade or so has put some real doubt into that theory as well.

        At this point they pretty much have almost everything else worked out, from the velocity whatever it was had, where it traveled, where it likely went kaboom. They just don't know what the make-up of the object was. This report goes a long way towards proving exactly what the celestial object was.
  • by Anonymous Coward on Tuesday May 27, 2008 @01:53PM (#23559141)
    The team visited Lake Cheko complete with their own catamaran

    Is it really that hard to spell 'cameraman' correctly? C'mon editors! Get on it!
  • The object is a space ship!
    • by cashman73 (855518)
      The object is a space ship!

      Umm,... that's been done before [imdb.com]. ;-)

      • by mlwmohawk (801821)
        Umm,... that's been

        Yes, many times over. I haven't seen Crystal Skull yet, but can name "Quatermass and the Pit aka 2million years to earth," "Sphere" with Dustin Hoffman, lets not forget "The Abyss" to name a few.

        However, it could make for a topical SciFi with some current events.
      • by Nathrael (1251426)
        I Want To Believe!
  • by Tisha_AH (600987) <Tisha.Hayes@gmail.com> on Tuesday May 27, 2008 @02:01PM (#23559281) Journal
    I have been following this team's progress with their investigation since it first came to light last year on the slash. They present a compelling case that there may be an impact body that created the lake.

    I can't wait and see their results from core drilling the lake.

    There have been several other impacts that were recorded by mankind (one in Estonia, recorded by Pliny the Younger).

    The Tunguska event could be mis-interpreted as a nuclear strike if it were to happen today over a populated area. We need to increase our understanding of the frequency and effects of bolide impacts upon our planet.
    • Re: (Score:3, Funny)

      by cavtroop (859432)
      We need to increase our understanding of the frequency and effects of bolide impacts upon our planet.

      Or, increase investment in bomb shelter manufacturers :)

    • by Jeff DeMaagd (2015) on Tuesday May 27, 2008 @03:00PM (#23560233) Homepage Journal
      The Tunguska event could be mis-interpreted as a nuclear strike if it were to happen today over a populated area.

      I thought nuclear strikes were highly radioactive. That and other clues would be easy to gather very quickly.
      • by Tisha_AH (600987) <Tisha.Hayes@gmail.com> on Tuesday May 27, 2008 @03:31PM (#23560655) Journal
        True, a nuclear weapon will leave radioactivity and this can be detected readily. Unfortunately we are still living in a world where submarines, bombers and missiles are pointed from country to country like loaded shotguns on a hair trigger.

        My fear is that someone would mis-interpret an incoming meteor as a nuclear weapon and initiate a launch on their perceived threats.

        If Moscow, Washington DC, Beijing or London were wiped out in a meteorite strike that was not detected before the destruction. Do you think that missile forces would not be put on high alert?

        We are not that far away from the days of "Fail Safe".
        • by geobeck (924637) on Tuesday May 27, 2008 @04:46PM (#23561921) Homepage

          My fear is that someone would mis-interpret an incoming meteor as a nuclear weapon and initiate a launch on their perceived threats.

          Not a fear likely to be realized, fortunately. If a major strategic city is vaporized, it's almost a certainty that it was destroyed by a strategic nuke. If a random area of countryside or open ocean is vaporized, it's almost certainly a meteotie/asteroid/comet.

          The percentage of Earth's surface covered by major strategic cities is miniscule. If an asteroid ever does hit one square on, that will be a sign that someone up there has decided to pull another Sodom & Gamorrah.

        • If Moscow, Washington DC, Beijing or London were wiped out in a meteorite strike that was not detected before the destruction. Do you think that missile forces would not be put on high alert?

          Sure, they'd be put on 'high alert'. But 'high alert' isn't 'launching'. (And there really isn't such a thing as 'high alert' anyhow, either you are on alert or you are not.)

          Unfortunately we are still living in a world where submarines, bombers and missiles are pointed from country to country like loa

        • by bkr1_2k (237627)
          We would almost certainly know when and approximately where any large enough celestial "body" would hit to forewarn at least the government of said nations, if not the citizens.

          We are pretty good at tracking things in the sky these days simply because we're worried about your scenario. Fear not, we won't be accidentally involved in a nuclear war. We'll handle that all by ourselves, the old fashioned way-some asshole will act stupid.
        • by jafac (1449)
          well - if one country has triggermen who are LOOKING for an excuse, a meteor impact would be a very convenient one.

          "oops! we thought it was a nuclear strike. my bad. Sorry."

          compare this to:
          "oops, we thought Saddam had active WMD programs, and was 40 minutes away from launching a chemical strike on Tel Aviv. Sorry. My bad."
      • by RexRhino (769423)

        The Tunguska event could be mis-interpreted as a nuclear strike if it were to happen today over a populated area.

        I thought nuclear strikes were highly radioactive. That and other clues would be easy to gather very quickly.
        What do you mean "very quickly"? By "very quickly", do you mean "Mr. President, we believe this to be a Russian first strike, and you must decide in the next 5 minutes if we are going to retaliate" quick?
      • by jmichaelg (148257) on Tuesday May 27, 2008 @03:45PM (#23560913) Journal
        The grandparent may be thinking of this event. [wikipedia.org] Had the bollide arrived a few hours earlier, it would have exploded over either Pakistan or India who were already shooting at each other over Kashmir. The explosion was twice as large as the Hiroshima blast.

        Whether both sides would have held their fire in that event is hard to tell.
        • Re: (Score:2, Informative)

          by Doc Ruby (173196)
          No, the timing of that event was as close as it was going to get to causing any damage to the Earth:

          However, since the Earth also travels around the Sun with an average orbital speed of 107,218 km/h, 3 hours earlier the Earth would have been about 300,000 km away from the intersection of its orbit with the projectile's orbit at the time that the South Asian region was rotated towards the projectile's path. So the projectile would have missed the Earth entirely by over 114 times the Earth's radius, about the

          • by himi (29186)
            Sure, it couldn't have worked out badly as it happened, but it demonstrates that this kind of event /does/ occur and that it could easily be mistaken for a nuclear explosion.

            What if its trajectory had been just right to have it impact three hours earlier? The timing was completely random, so it could have gone either way (or any other way).

            himi
            • by Doc Ruby (173196)
              What if a very tiny meteorite hit the new president while being inaugurated? That would set off World War IV!

              Our world is certainly too much armed to the teeth, on hair triggers around the globe, jumping to believe the worst of each other. But inventing such an improbable confluence of several improbable events as a threat worth addressing is almost as irrational as pretending that the mutual destruction machine we've erected is not a threat in itself. There are real threats making that machine risky to dea
      • Yeah, and the plutonium came from Hanford, Washington and was given on the Q-T to Tel Aviv.
  • by Anonymous Coward on Tuesday May 27, 2008 @02:07PM (#23559381)
    If you saw that documentary on him called The Prestige, you know he's capable of almost anything.
    • In actuality, it's David Bowie that has the creepy electrical powers; Tesla was good, but Bowie worked better for the movie.

      Personally, I'm in the group that thinks Flight of the Conchords did it by the power of Bowie. They took acid, then caused the trees to explode by playing David Bowie music for them. Even though Bowie himself wasn't there, the music still had that much power.
  • And vodka, and borst, and potatoes.
  • Evidence against (Score:4, Informative)

    by Anonymous Coward on Tuesday May 27, 2008 @02:07PM (#23559389)
    "The various samplings from the bottom of Lake Cheko (P'yavchenko, Kozlovskaya) revealed extensive development of silt up to 7 meters deep, indicating an ancient origin for the lake (tentatively estimated at 5000 to 10,000 years), thus completely contradicting the hypothesis of the formation of the lake as a result of the Tunguska meteorite fall (V. Koshelev, 1960)."

    http://abob.libs.uga.edu/bobk/tungmet.html [uga.edu]
    • Re:Evidence against (Score:5, Informative)

      by Anonymous Coward on Tuesday May 27, 2008 @02:45PM (#23559963)
      Yes, which, if you had read the paper linked to, you would see that they tackle said claim directly.

      However, as our study progressed, we began to question the old age of the lake for the following reasons:
      1 Our sub-bottom acoustic reïection data show that, of a 10 m thick sediment pile, only the top
      1 ± 0.5 m is laminated, ïne-grained, normal lacustrine sediments (Gasperini et al., 2007). The
      lower chaotic material appears not to be deposited by normal lacustrine sedimentation.
      2 210 Pb and 137 Cs datings on sediment cores from the lake suggest sedimentation rates of roughly 1cm/yr)1(Gasperini et al., 2001). Assuming this rate is mostly due to ïne-grained material transported into the lake from the Kimchu
      River, the thin lacustrine sequence is compatible with a young (100 years) age for the lake.
    • Re: (Score:2, Informative)

      by Anonymous Coward
      from TFA:

      "we started our work at
      Lake Cheko on the assumption that
      it was older than the TE: our objective
      was to find markers of the TE in the
      lake's sediments. However, as our
      study progressed, we began to question
      the old age of the lake for the
      following reasons:
      1 Our sub-bottom acoustic reflection
      data show that, of a 10 m thick
      sediment pile, only the top 1 ± 0.5 m is laminated, finegrained,
      "normal" lacustrine sediments
      (Gasperini et al., 2007). The
      lower chaotic material appears not
      to be deposited by
  • So what's the adjective from Lake Cheko? Chekovian? Maybe someone's finger slipped on the photon torpedo launcher controls, and they came back in time to rename the lake -- so it went on his permanent record.
    • Well, if you have a loaded photon torpedo launcher in the first act, it had better be fired before the end of the third!
  • this is just astroturf advertising

    for the upcoming x-files movie this july [xfiles.com]

    relax, i'm joking, but what is described sounds exactly like an x-files episode, doesn't it?
  • by the_arrow (171557) on Tuesday May 27, 2008 @02:21PM (#23559599) Homepage
    According to Wikipedia [wikipedia.org], the lake is at 60.964 N and 101.86 E. Might make it easier to find in Google earth.
  • by davidwr (791652) on Tuesday May 27, 2008 @02:24PM (#23559631) Homepage Journal
    In Soviet Russia, Mosquito suck YOU!

    Oh ... wait ... nevermind.
  • by Anonymous Coward on Tuesday May 27, 2008 @02:36PM (#23559811)
    The paper in the posting is a reply to a comment with the contrary interpretation [blackwell-synergy.com] (i.e. that Lake Cheko isn't an impact) [Same paper as PDF [blackwell-synergy.com]]. The critical comment should be cited too.

    The original paper by Gasperini et al. (2007) [blackwell-synergy.com] is also available as PDF and HTML [blackwell-synergy.com].

    I'm not particularly convinced by the evidence they present. It's quite circumstantial. What they need to find and sample is an ejecta-related layer in the lake stratigraphy or in a lake nearby, and you'd think that if such a large impactor hit the ground there would be plenty of micrometeorite debris in the sediments of the surrounding area. Geomorphological evidence and age just isn't enough.

    • Re: (Score:3, Informative)

      by aslagle (441969)
      That would be why they're planning to return and make core samples....
    • I'm with you: when I read the original paper, I wasn't really bowled over by their case. In fact, I was a little concerned about the contrary evidence (which they addressed, but generally only in an iffy fashion). This lake *may* be the impact crater, but it's far from certain in my mind. I'd expect Slashdot to do better with differentiating between generally accepted theories and shaky ones.
    • Personally, I find the shape of the lake itself to be indicative of an artificial (as in non-erosion related) nature. The entry and exit points in the lake are very close together, and on the same side. The area is generally flat (check out Google Earth for that), except for the depression that forms the lake.

      There is also the explanation of a sink hole, but that would be rather round, instead of elongated. The final proof would definitely be the discovery of micrometeorite material in the sediments, or oth
  • The extra-terrestial impactor (i.e. asteroid/comet) hypothesis has been around for a long time. It has been questioned for several reasons. In particular, (i) there were bright/white nights before the event, and (ii) debris has been found in crash sites from meteorites 10000 times lighter, whereas there is none at Tunguska.

    For more details and an alternative explanation, see the following.
    W. Kundt (2001), " The 1908 Tunguska catastrophe [ias.ac.in]", Current Science, 81: 399-407.

    Dr. Kundt is at the Universit
  • well... (Score:3, Interesting)

    by murka (1295573) on Tuesday May 27, 2008 @03:21PM (#23560493)
    Wow, catamaran is an argument. My mother [irkutsk.com] [In Russian] was on the first "Complex Independent Expedition" and on the few following ones in the 60s. (She is available for questions). Many many scientists spent years on the spot, checking all possible hypothesises from a crashed space craft to an exploded ice comet. The result: no actual material ever found and the forest damage shows that the explosion took place far above the surface. BTW, there are plenty of lakes there, as the area is pretty wet. Pick one on Google Maps to fit your favorite hypothesis.
  • Semen Semenov (SciAM article) got teased as a kid?
  • by GreyDuck (192463) <greyduck@@@gmail...com> on Tuesday May 27, 2008 @03:32PM (#23560673) Homepage
    From the SciAm article's photo caption: "In this artist's conception, Semen Semenov, who witnessed the blast at a distant trading post, starts to feel the heat."

    That's... a really, really unfortunate name, dude.

    (I love that they managed to work "heat" and "conception" into a sentence about a guy named Semen.)
  • hey also imaged an object under the sediment that may be a fragment of the impacting body.


    That would be a downed UFO [wikipedia.org].
  • Mosquitos ++ (Score:5, Interesting)

    by RockDoctor (15477) on Tuesday May 27, 2008 @04:04PM (#23561241) Journal

    the working conditions in the Siberian summer. Think: mosquitos.
    Mosquitoes ad nauseam.

    Mosquitoes to the point of anaphylaxis (well, that was what the rig's medic was afraid of, which is why he evacuated me back to the base camp).

    Mosquitoes that can maintain eye contact at a meter range (i.e you can see it's eyes at a meter range) through the window of the car, then launch an assault on this nice juicy mammal, only being stopped by the glass of the window.

    Mosquitoes that can keep pace with you while driving at 40km/hr on a dirt road.

    Mosquitoes that can bite you through a leather glove, 20 times in one evening's work. They choose the clipboard hand, because you can't swat with that and get your work done.

    Don't get me wrong - Siberia is interesting, but don't forget the industrial strength insect repellent and the appropriate clothing. If you don't know what's appropriate, ask a bee keeper. And don't forget the vaccination against tick-borne encaphalitis (which includes Lyme disease, I believe), which takes several weeks to become effective.

    • Re: (Score:3, Funny)

      by 21mhz (443080)
      Accordingly to one hypothesis, the cause of the Tunguska event was a spontaneous explosive combustion of a 5 cubic km cloud of gnats.
    • Re: Mosquitos ++ (Score:4, Interesting)

      by mev (36558) on Tuesday May 27, 2008 @06:20PM (#23563227) Homepage
      That is a little more severe than I encountered when bicycling across Russia last summer.

      Between end of May and mid-July, we traveled through the West-Siberian plain. We generally encountered four major types of flying insects there:
      • Big biting flies, 2-3cm; could keep up with a 20km/hr cyclist. Got situated before biting, so if you were quick enough, could swat them away. Seemed to be gone if it was too cold.
      • Mosquitoes; did not keep up with a 20km/hr cyclist. Particularly active in morning and evening.
      • Small biting flies; not a problem when traveling but a problem when camping
      • Small non-biting flies; not a big problem

      Depending on where we camped, we also had problems with ants.

      The density of the mosquitoes and biting flies were approximately the same as I've encountered on previous bicycle trips in northern Yukon and Alaska. However, they were much more widespread and much more continuous, day after day. Every place we camped for a month and a half, we had insects. Sometimes worse, but always present. (That was not the case in Alaska.) If one were working in one place or traveling slower than 20km/hr, I could see why that would be even worse.

      However, either the situation is even worse where RockDoctor was at than where I cycled or there is (slight) exageration here, e.g. I encountered biting flies that could do 20km/hr but not mosquitoes.
      • by Bucc5062 (856482)
        I just have to ask, how does one do this? I mean you bike across Alaska, Russia, the yukon, and can report in detail about bugs. I sit here in my Southeastern home and wonder. Do you own a home, have family, do you have a job, and if so how do you pay for the time off and travel.

        I mean, this cannot be cheap. Do you get sponsors? Are you a scientist with a grant? I love my home, my job is okay, but Ithink when I read you're post 'Wow, that would be cool' yet I cannot imagine how one disconnects from re
        • Re: (Score:3, Informative)

          by mev (36558)
          Not married, no kids. Own a duplex, have tenants to take care of it when I'm gone. Work in tech which pays fine and have had an employer that has been willing to allow an occasional LOA. Live frugally and save money rather than rely on sponsors.

          Russia is a relatively expensive country, but bicycle travel and camping is not that expensive. It is also a good way to experience a country since it brings you in out of the way places without as many tourists.
      • by Cyberax (705495)
        West-Siberian plain (and most of the southern Siberia) is fine.

        Northern Siberia, however, is hell. I always wished for army-style chemical protection suite when I worked in Siberian tundra.
      • by RockDoctor (15477)

        That is a little more severe than I encountered when bicycling across Russia last summer.

        Cycling is one thing. I'd be very worried about the attitude of the Russian drivers to cyclists. I don't think they'd be very friendly.

        * Big biting flies, 2-3cm; could keep up with a 20km/hr cyclist. Got situated before biting, so if you were quick enough, could swat them away. Seemed to be gone if it was too cold.

        That's probably the big car-chasing ones I met.

        * Mosquitoes; did not keep up with a 20km/hr cyclist. Partic

        • by mev (36558)

          Which parts of West Siberia were you in?

          We cycled across all of Russia from St Petersburg to Vladivostok going via Kazan, Ekaterinburg, Omsk, Novosibirsk, Kemerovo, Krasnojarsk, Irkutsk, Ulan Ude, Chita, Khabarovsk mostly on the larger roads. Five months in total. Almost no insects before Kazan at end of May. Also, not as many insects after Krasnojarsk in mid-July. Thats why I singled out Western Siberia though there is also a time component.

          We typically camped not too far from the road, and there is a lot of low marshy ground. Typical proce

          • by RockDoctor (15477)

            We typically camped not too far from the road, and there is a lot of low marshy ground.

            You've just described most of Russia east of the Urals >G< . Well, to a first approximation anyway. A few hundred miles north-south makes quite a difference between degree of woodland versus open swamp, but it's all pretty swampy.

            Typical procedure when we stopped for the day was to wear rain gear and mosquito net head gear while setting up tents.

            Those "net head" hats are a life-saver, aren't they?

            Once tents were up,

    • This reminds me of a Memorial Day conversation: "Are mosquitoes any good at all?" That is, do they play some small important role in the ecosystem such that we'd miss them if they were gone?

      I know, they kill millions of people with malaria, and we're not ready to launch the familiocide genetic weapon yet, but what will future humans decide?
      • by RockDoctor (15477)

        This reminds me of a Memorial Day conversation: "Are mosquitoes any good at all?" That is, do they play some small important role in the ecosystem such that we'd miss them if they were gone?
        They perform the most important function in the world (from the perspective of the genes inside a mosquito) : they produce baby mosquitos.
        No seriously, that's the answer. All the answer that's necessary.
        • No seriously, that's the answer. All the answer that's necessary.

          Why would that cause us to not want to eradicate them?
          • by RockDoctor (15477)

            No seriously, that's the answer. All the answer that's necessary.

            Why would that cause us to not want to eradicate them?

            It doesn't address the question at all. To find the answer for that question, you need to look into your own morals. Or, if you've surrendered your moral judgement to someone else, ask them.

            I chose to not pursue studies and technologies that would or could lead to extermination of mosquitoes (or any other organism), but that's a personal choice. I am not your guide, and nor is nature.

            Con

            • Hrm, I think you replied to my original message where I specified this as a problem for future generations and the problem being malaria, but sorry if that was unclear.

              I suspect that unless any of the sterile breeders or vaccination programs are effective, at some point humans will make this choice, though I'm not sure I'll be around to see it.
      • by conureman (748753)
        Bird food. Huge role. Before humans learned to disregard common sense we didn't build our towns on swampland. Not a lot of population density in Siberia. I've got my own little bug paradise by the Skeena River in B.C. but it is habitable.
        • Bird food. Huge role.

          Good point; bats too.

          Before humans learned to disregard common sense we didn't build our towns on swampland.

          I've got mosquitos aplenty and I don't live near any swamps. Ours are annoying but not deadly.

          I've got my own little bug paradise by the Skeena River in B.C. but it is habitable.>

          Yeah, but if your children were dying you might feel differently.
  • Carolina bays (Score:5, Interesting)

    by Solandri (704621) on Tuesday May 27, 2008 @05:00PM (#23562137)
    There's a similar mystery right here in the U.S. The Carolina bays [wikipedia.org] are elliptical depressions scattered throughout the southern Eastern U.S. seaboard [google.com]. They're mostly filled with water so form small lakes, ponds, or wetlands. But they're all approximately the same shape and orientation (but not size). A variety of theories have been posed as to their origin, including a glancing comet strike (shallow angle impacts produce elliptical craters, not round). They're not as well-known as the Tunguska event, but they're a lot more accessible if you wanted to visit a mysterious possible impact site.

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