Tunguska Impact Crater Found?

BigBadBus writes in with a claim by an Italian team that they may have found an impact crater resulting from the 1908 Tunguska explosion over Siberia. The BBC story quotes a number of impact experts who doubt the Italians' claim. "A University of Bologna team says a lake near the epicenter of the blast may be occupying a crater hollowed out by a chunk of rock that hit the ground. Lake Cheko — though shallow — fits the proportions of a small, bowl-shaped impact crater, say the Italy-based scientists. Their investigation of the lake bottom's geology reveals a funnel-like shape not seen in neighboring lakes. In addition, a geophysics survey of the lake bed has turned up an unusual feature about 10m down which could either be compacted lake sediments or a buried fragment of space rock."

To save you some googling

[Anonymous Coward]

Here's [keyhole.com] two views of Checko Lake from Google Earth and Google Maps

well

[mastershake_phd]

After the many expeditions to Tunguska, wouldn't one of them have noticed a crater shaped lake? From what I saw on a documentary about it the first expedition drained and dug in every hole they found in that swamp.

Not just Tesla

[Anonymous Coward]

The wiki article on Tunguska lists several speculative causes of the 'event' in addition to Tesla. It seems to be the Russian equivalent of Area 51.

http://en.wikipedia.org/wiki/Tunguska_event [wikipedia.org]

Speculative hypotheses

Scientific understanding of the behaviour of meteorites in the Earth's atmosphere was much sparser during the early decades of the 20th century. Due to this lack of knowledge, as well as a paucity of scientific data about Tunguska due to Soviet secrecy during the Cold War, a great many other hypotheses for the Tunguska event have sprung up, with varying degrees of credibility. The hypotheses listed below are all rejected by modern science and by skeptics who generally see them as being gross violations of Occam's Razor

Natural H-bomb

In 1989, the astronomers D'Alessio and Harms suggested that some of the deuterium in a comet entering the Earth atmosphere may have undergone a nuclear fusion reaction, leaving a distinctive signature in form of carbon-14. They concluded that the release of nuclear energy may have been almost negligible. Independently, in 1990, César Sirvent proposed that a deuterium comet, i.e., a comet with an anomalous high concentration of deuterium into its composition, may have exploded as a natural hydrogen bomb, generating most of the energy released. The sequence would be first a mechanical or kinetic explosion, and instants later a thermonuclear reaction generated by this first explosion. This hypothesis would explain the inconsistences related to an unusual high ratio of electromagnetic energy / kinetic energy and cited in the famous paper by Cowan, Atluri, and Libby published in Nature.[citation needed] It is, however, inconsistent with knowledge both of the composition of comets and of the temperature and pressure conditions necessary for initiating a nuclear fusion reaction.

[edit] Black hole

In 1973, Albert A. Jackson IV and Michael P. Ryan, Jr., physicists at the University of Texas, proposed that the Tunguska event was caused by a "small" (around 10-20 g to 10-22 g) black hole passing through the Earth. Unfortunately for this hypothesis, there is no evidence for a second explosion occurring as the black hole exited the Earth and it has not gained wide acceptance. Furthermore, Stephen Hawking's subsequent hypothesis that black holes radiate energy via Hawking radiation indicates that such a small black hole would have evaporated away long before it could encounter the Earth.

[edit] Antimatter

In 1965, Cowan, Atluri, and Libby suggested that the Tunguska event was caused by the annihilation of a chunk of antimatter falling from space. However, as with the other hypotheses described in this section, this does not account for the mineral debris left in the area of the explosion. Furthermore, there is no astronomical evidence for the existence of such chunks of antimatter in our region of the universe. If such objects existed, they should be constantly producing energetic gamma rays due to annihilation against the interstellar medium, but such gamma rays have not been observed.

[edit] The Wardenclyffe Tower

It has been suggested, by Oliver Nichelson, that the Tunguska explosion may have been the result of an experiment by Nikola Tesla using the Wardenclyffe Tower, performed during one of Robert Peary's North Pole expeditions.[6]

[edit] UFO crash

UFO aficionados have long claimed that the Tunguska event is the result of an exploding alien spaceship or even an alien weapon going off to "save the Earth from an imminent threat". This hypothesis appears to originate from a science fiction story penned by Soviet engineer Alexander Kazantsev in 1946, in which a nuclear-powered Martian spaceship, seeking fresh water from Lake Baikal, blew up in mid-air. This story was inspired by Kazantsev's visit to Hiroshima in late 1945.

Many events in Kazantsev's tale were subsequently confused with the actual occurrences at Tunguska

Not a troll

[drinkypoo]

It's not a troll. It's called humor. And it's entirely ontopic and appropriate as well - the article basically has a bunch of people saying "it might be some shit" but they have no proof whatsoever. They claim to have ruled out several other possibilities which led them to the "conclusion" (how do you come to a conclusion with no evidence?) that it was the Tunguska impact crater. Now let's see, how many problems are there with this?

1. Tunguska probably wouldn't even have a crater, because it was an airburst. At best, it would have several small ones, which might not even be detectable any more.
2. The article claims that if there were a crater, it would be shaped differently.
3. There is no supporting evidence that this was the Tunguska crater.

Now, if they dig into this lake and figure out what the submerged lump in it is, which might be a rock and might just be a lump of sediment, then this will be more interesting. But this is a completely non-story story. There are no facts here, other than that some people have made an assumption which might or might not be warranted, because they lacked imagination to come up with hypotheses they couldn't shoot down.

A better title would be "Scientists believe they have located Tunguska Crater without corroborating evidence".

Parent comment, even if intended to be a joke just about the name of the Uni (I do not believe it is, based on having RTFA, shock amazement) is still entirely apt. Perhaps the bonehead who modded it troll should check out the moderation guidelines?

Re:Shouldn't this be easy to prove?

[Kelson]

According to the article, they plan on sending another expedition next year and drilling at the lake.

Re:Homer Simpson Says

[nospam007]

Mmmm.... University of Bologna ...
As I foreigner who doesn't get the joke, anybody explain this for us dummies? Some commercial we missed?
--
From Wiki:
The University of Bologna (Italian: Alma Mater Studiorum Università di Bologna, UNIBO) is the oldest continually operating degree-granting university in the world, and the second largest university in Italy. It is located in the city of Bologna. The University of Bologna was the first university founded in the western world (AD 1088) and since 2000, its motto has been Alma mater studiorum (Latin for "fostering mother of studies"; cf. Alma mater). The university received a charter from Frederick I Barbarossa in 1158, but in the 19th century, a committee of historians led by Giosuè Carducci traced the birth of the University back to 1088. The University celebrated its 900th anniversary in 1988, making it arguably the longest-lived occidental university.

Re:Homer Simpson Says

[terrymr]

Wikipedia:

Bologna sausage is an American version of the Italian mortadella (a finely hashed/ground pork sausage with lard pieces, which originated in the Italian city of Bologna). The American version can alternatively be made out of chicken, turkey, beef, pork, or soybeans. It is commonly called bologna and often pronounced (by hypercorrection) and/or spelled baloney. The "baloney" pronunciation can be used to mean "lies" and/or to express disbelief (see below).

Unfortunately

[porkchop_d_clown]

The most widely accepted explanation for not finding the crater is that there isn't one: Most geologists believe the Tunguska object exploded in the air. (This sounds crazy, but it's apparently possible - just as a person doing a belly flop off a cliff is going to be killed by the impact, a meteor can be destroyed by the impact with the lower atmosphere.)

http://en.wikipedia.org/wiki/Tunguska_event [wikipedia.org]

Re:Unfortunately

[btgreat]

Even the researchers from the article believe that.. The difference here is that they think a small piece of the airbursted object survived and hit the ground, causing a small crater - the lake. At least, thats what I got out of TFA.

mortadella ??

[giampy]

Funny that as an Italian i never had the slightest idea on why americans put the Bologna name on the pork sausage ...

Actually, any searches for Bologna invariably returns the city, unless you actually search for "Bologna Meat" which returns this:

American Bologna sandwich meat got its name from the northern Italian town of Bologna. But this favorite of kid's lunches is not the same as the distinctively spiced Italian original, called Mortadella and made in the villages around Bologna, a major trading spot. Traders may have picked up the sausage in Bologna, and the town became identified with the sausage. By the late 19th century in England and America, "bologna" had become the generic name for any type of pork sausage from the Italian town.

Which solves the mistery, except that i would add that "Bologna" evolved to something completely different than Mortadella.

Re:Lewis Tully?

[jacksonj04]

Why bother? BBC articles are neither ad-filled nor multi-paged.

Location

[Alien54]

Ground Zero = 6055N, 10157E (approximately)

Google maps doesn't have much detail, but Google Earth is much better

You can make out individual trees, but I do not see much in terms of individual logs in the blast pattern. Using the BBC info as a guide, you can easily see Lake Cheko