An Italian team claims to have found the crater for the Tunguska 1908 event.
I love the bad science show on The History Channel about Tunguska. (Was it a crashed UFO?)
This is an interesting claim (not the UFO claim).
Odd, I thought this was considered mostly settled, in that the meteor involved exploded in-air, which prevented a very noticeable crater from forming. Finding material isn’t very unusual, as it was ejected in a massive area around where it occurred, and scientists back in the 20’s had already found material from the meteor and confirmed its extraterrestrial origin.
Moving thread from IMHO to MPSIMS.
Odd, my understanding was that they hadn’t found meteoric material and the working theory was that it was a comet that had exploded some point before it would have impacted on the ground.
Looks my memory was at least partially correct, at least according to Wikipedia:
“Expeditions sent to the area in the 1950s and 1960s found microscopic glass spheres in siftings of the soil. Chemical analysis showed that the spheres contained high proportions of nickel and iridium, which are found in high concentrations in meteorites, hinting that they were of extraterrestrial origin.”
I researched this [retty thoroughly several years ago, reading a lot of the original reports (in translation – they’re there if you look for the,m).
Leonid Alekseyevich Kulik visited the site twenty years after the explosion (World War I, the Revolution, and other things prevented an earlier visit), and went back several times in the years that followed, until his death. They found the trees lying flat, pointed away from the center of detonation, and standing upright under the explosion site. As noted above, it exploded in the air.
Kulik and company investigated the site pretty thoroughly. They found that the heat of the explosion had melted the permasfrost and left karst-like depressions in the ground, covered with a twety-year growth of sphagnum moss. There were a lot of pools in these depressions, and they dug into one and drained it, and drilled into the ground. I’m sure they concentrated on the region at the center of the blast (Kulik mapped it, and had flyovers done to construct a photomosaic of the devastated region. It was easy to pinpoint the blast center – all the tree trunks that had been knocked down pointed away from it.)
Contrary to what’s usually reported, Kulik said that he DID find pieces of meteoric matter, including one fist-sized piece. (The much later circa 1960 expeditions found a lot more micrometeorites, most of them spherical bits that suggested they had been melted and refused by the explosion.)
I don’t know where this lake sits relative to the center of the explosion. If it’s far away, Kulik and company (and possibly even the later expeditions) wouldn’t have looked there. I don’t recall any of Kulik’s reports mentioning a big lake that the mass might lie in – and I think he would’ve reported that. There’s no doubt that the thing blew up in midair – the evidence of the trees alone, along with the lack of a significant crater at that center confirms this, and modelling done in the years since supports this. A host of theories trying to explain that explosion – including a “dust meteorite”, a ricochet, a comet head, antimatter (suggested independently three times) and even a quantum black hole* have been suggested, along with more science fictional suggestions. the cometary hypothesis held sway for the longest time, the idea being that many of the chemical compounds, unstable at high temperatures and in atmosphere could’ve contributed to the blast, and that the ice making up much of the mass would’ve evaporated, and that any stony or glassy solid mateerial would have been in small pieces scattered throughout, and easily broken up and melted into those microspheres.
*the author of this one sheepishly admitted it was tongue-in-cheek, after some back-of-the-envelope calculations proved it absurd. The Tunguska Event has always been a sort of Astrophysics Rorschach test, with each new explainer seeing his pet theory manifest in it.
Yeah, that’s why I love it! And each crazy theory to come out is more entertaining than the last. (Well, except this one is relatively tame compared to some of the others - and maybe not so crazy.)
So it’s not a Tesla death ray, then. Bother.
No, but back in the 1960s some Soviet guy was claiming that some aliens in Cygni 66 saw the radio emissions from the eruption of Krakatoa, thought they were radio signals, and replied with a beam of some kind that ended up causing the explosion.
I suspect the original article (which I haven’t seen) was either intended to be tongue-in-cheek, or else from some Russian version of the National Enquirer, but it was reported in the US in Time magazine. It wasn’t treated entirely seriously, but I don’t think it was treated as th obvious bozo theory it was. And weird stuff about the meteorite that was intended to be serious – Like Aleksandr Kazantsev’s article (accompanying an SF story by him) claiming that radioactivity was found around the site*, suggesting it was an exploded alien spacecraft – kept coming out of Russia.
- Not true.
I always assumed that it was the U.S. destroyer escort USS Eldridge that had exploded. Two mysteries solved.
About 8km north-north-west. See the more detailed article and map on this BBC page.
That top picture on the BBC link is pretty damned misleading – it looks like an impact crater. But it’s not a picture. Both the map further down and the real picture (the top one is a computer-generated one) don’t look anywhere near as impressive, or as likely to be due to an impact.
My opinion – considering that the blast was pretty impressive in its strength*, I’d be surprised that some large piece survived, and then went on its path undeviated by that disruption.
- All the early data – up through the 1960s – placed the blast at about the size of a Hiroshima explosion, based on quite a large number of factors (that were listed in the various papers). More recently people have been quoting a different figure that I do not know the origin of. But i haven’t kept up with the latest research on this.
Cal is the new figure suggested for the size/power of the explosion greater or lesser than the old figure? Considering that I recall that the event was heard in London and Paris, I’d think that Hiroshima would represent something of a minimum power required.
(Caveat - my memory may be mistaken, of course…)
ETA - and yeah, my memory is FUBARed again - pressure changes were detected in London, but not necessarily heard. Oops
But how does this relate to the destruction of the Maine? Riddle me that.
Quite simple, really. When the Maine blew up in Havana harbor there was a large amount of coal dust ejected from the bunkers. This cloud of superheated coal dust then went directly to the upper atmosphere, where it remained energized by cosmic and solar radiation. It wasn’t until 1908 when the cloud descended, en mass, over Tunguska, that the particles of dust would be able to combust when the static of the cloud generated a spark.
(nodnodnodnodnod)
Damned if I can remember. My memory’s FUBARed, too.
But those microbaometer traces from London (and elsewhere – there are recordings from all over the world) were a factor in determining the size of the explosion.
[Paul Harvey]If you drew a line from the center of the impact through the core of the Earth, do you know where the other end of that line would be…? The Bermuda Triangle. It’s true. And now you know … the rest … of the story.[/PH]
You laugh, but I actually saw a story about precisely this in some National Enquirer-type paper back about 1976. They even had a picture of a black hole Potential Energy well superimposed on a map of the Bermuda Triangle. How can you argue with that?
with a globe?
Does Google Earth have a good image of this site? Guessing that it might.
Another interesting feature in the U.S. is called “Upheaval Dome” in or near Canyonlands National Park. It looks an awful lot like an impact crater, but I am not sure.