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Tunguska Blast Was a Small Asteroid
malachiorion writes "The Tunguska event, an explosion on June 30, 1908, cleared an 800-sq.-mi. swath of Siberian forest. Was it a UFO crash? An alien weapons test? Now, Sandia National Laboratories has released its own explanation for the Tunguska event. Using supercomputers to create a 3D simulation of the explosion, the Department of Energy-funded nuke lab has determined that Tunguska was, indeed, the explosion of a relatively small asteroid. The simulation videos are well worth checking out — they show a fireball slamming into the earth from the asteroid's air burst. The researchers caution that we should be keeping watch for many more small, potentially earth-impacting asteroids than we are currently tracking."
What else would it have been?
It seems that while the asteroid itself did not cause as much damage as previously believed (3-5 megatons vs 10-20), the asteroid was most likely much smaller than had been estimated. Too bad the article doesn't give some numbers about the size. Pretty scary thinking about one of these things hitting on top of or near a major population center.
...how the populations (including the military) in some of the more... nervous areas of the globe would react to a suddden blinding light in the sky followed by an enormous blast wave.
"None are more hopelessly enslaved than those who falsely believe they are free." -- Goethe
That last sentence made me wonder.. Would there be any chance of a small asteroid (one that could cause some problems) currently heading for earth not be detected yet by scientists?
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Everybody knows it was Santa crash landing
Those videos were really informative to me. I had always heard and read reports about how an "exploding" comet or asteroid had caused the devastation. But why and how would these things explode?! Well, they don't. But the all the momentum they transfer to the air creates a very devastating shock wave.
Moderation: +1 pwnage
What'll happen if one hits water instead of dirt? More evaporation leading to somewhat elevated precipitation downwind? Or an extreme increase in clouds leading to an ice age?
You mean after the gigantic tsunamis die down? Well, once the rebuilding begins on a global scale, elevated precipitation will likely be the least of one's worries, especially if you live within 20 miles of the coast.
khasim (12/9/06): In a blind taste test, more people preferred Coke over the Pepsi that I had previously pissed in.
I'm currently reading Arthur C. Clarke's 'Rendezvous with Rama', which opens with the lines "Soon or later, it was bound to happen. On June 30, 1908, Moscow escaped destruction by three hours and four thousand kilometers -- a margin invisibly small by the standards of the universe."
In the book, we humans then go on to set up systems to track asteroids that may be a danger to earth, and set up defense systems against them. I know that we currently track some, but how well funded are these organizations that do this? This is really something that is quite important, as it is almost certainly just a matter of when, not if. Do we have systems in place that will allow us to destroy or divert any large asteroids that are determined to be on a path to impact with earth?
A new study has been released proving that the fireball event in the server room was caused by slashdot and not an asteroid
My Aurora : http://www.youtube.com/watch?v=o91ZsGwJYyg
FB : https://www.facebook.com/TanveersPhotography
I'm not a US resident but isn't slashdotting/DoS-attacking a federally owned site a criminal/terror offence in the US?
Break the sound barrier - bring the noise.
Seems like alot of money wasted proving something that happned to another country.
:)
Which means that we have finally figured out how tesla did it. And now we have something to hide.
So offer up a good explanation. And the mystery is 'solved'.
A 3-5 megaton blast over the Atlantic wouldn't cause so much as a rough surf advisory in Key West. In comparison, the USA built a 45 megaton bomb and the USSR's fission-fusion-fission Tsar Bomba would have been 100+ megatons had they not taken the sensible precaution of replacing the final fission stage with inert lead. If a mere 5 megaton warhead could cause such worldwide devastation, I'm pretty sure someone would have mentioned it before now (and trust me, I've read just about every far-fetched doomsday scenario imaginable.)
As for the possibility of similar-sized asteroid impacting the ocean instead of exploding above it--well, the article only says that the asteroid is now thought to be "only a fraction as large as previously published estimates". That doesn't tell us anything. The Tunguska asteroid may or may not have been large enough to trigger a tsunami had it impacted an ocean instead of exploding over land. I'm going to assume that an impact will usually be less energetic (though perhaps more concentrated) than a heat-induced explosion, in which case no, the Tunguska asteroid never posed a significant threat to the world as a whole.
That said, the Tunguska explosion is still fascinating as hell. I know that there's a lot of very strong evidence pointing to the asteroid theory, but it's still fun to toy with conspiracy theories. The atomic bomb was first being conceived of, Tesla's Wardenclyffe Tower was being tested (by some accounts, it was brought online the day before the explosion)... it's all absolute rubbish, to be frank, but it's very entertaining rubbish.
The computer simulation is interesting, but the Tunguska event is unlikely to be an asteroid. There were strange events reported in the area for days prior to the explosion, there were odd lights, etc.
An alternative explanation was proposed by Wolfgang Kundt, a researcher at the Institut für Astrophysik, University of Bonn:
Kundt W. (2001),
“The 1908 Tunguska catastrophe: An alternative explanation”,
Current Science, 81: 399–407.
The basic proposal is that there was a natural gas leak, from the Earth. The gas rose to a certain height, then drifted downwind. After several days, a lightning strike ignited the airborne gas, and the flame then traveled along line (of drifted gas), to the ground source.
It is worth reading the article. An asteroid impact is sexy, but the alternative explanation fits with the data much better.
It says that it was smaller than first thought, but it doesn't say how big the damn thing was! Do they know the diameter? Do they know its mass? How about its density? I want to know how big an asteroid has to be in order to make a blast of a few megatons.
dom
OK, we shouldn't expect media people to know everything, but we are very poorly served by their almost total scientific ignorance. I suspect that politicians would have become interested in global warming much sooner were the mass media not so piss poor at explaining scientific issues to the public, and almost perversely proud of it.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
The BBC's Horizon program ran a story about this last year
What strikes me (excuse the pun) is that now they've determined it was an asteroid the attitude is "oh well these things happen - at least it wasn't someones big secret weapon".
Ok, so let me ask, whats the difference?
If it was a big super weapon like a Nuke everyone would be panic strikken. Because it was just a asteroid there is no reason to worry. Lets not forget that large enough asteroids could wipe out the entire planet (not just one or 2 countries like our nukes..)
On the trail of common sense, why is a football player a hero, yet we have troops in Iraq that are only recognised as a hero once they arrive home in a wooden box with lots of press coverage?
The world has gone completely mad..
The videos total over 56 Megabytes, so I have put up a mirror Here
echo '[q]sa[ln0=aln80~Psnlbx]16isb572CCB9AE9DB03273snlbxq' |dc
Dammit, don't go smear my wonderous conviction with your filthy science. Astronomy is just Astrology in fancy dress anyways... ;P
If you see a rock violating the law of gravity, then the law is wrong, not the rock!
Somebody farted into a camp fire.
to destroy the Arachnid threat.
because now with better computer simulations they can loft nice little toys into orbit that contain no nuclear matter, thereby not alerting any enviromentalist or anti-nukes, and have a very nice and clean weapon system.
I expect a lot more studies on the compositions of asteroids to determine just "which" kind is such a threat to us, which of course can lead to making these threats. All in the name of science.
* Winners compare their achievements to their goals, losers compare theirs to that of others.
No, this is an alien weapons test: http://science.slashdot.org/article.pl?sid=07/12/17/2149239
For a nice date: Call strftime(3C)!
In the 1960s the accepted story was that a meteorite 'exploded' over Siberia. It wasn't until much later that I learned that it was caused by Tesla. ;-) http://prometheus.al.ru/english/phisik/onichelson/onichelson.htm
5 megaton TNT = 2e16 J = 0.5 mv^2
Now the typical impact speed of an asteroid is around 20 km/s:
0.5 m (2e4 m/s)^2 = 2e16 J
2e8 m (m/s)^2 = 2e16 J,
which yields the mass:
m = 1e8 kg.
Assuming the average density of the asteroid to be about that of water (1000 kg per cubic meter), we get the volume:
V = 1e5 m^3
and, assuming a spherical shape, the diameter:
d = 58 m.
Many known asteroids are somewhat denser than water (1000-4000 kg/m^3).
To get one week's advance warning for the blast, the asteroid must be spotted 10 million kilometers away.
Tesla destroyed all his work notes that lead to this explosion.
I am the unwilling control for my Origin.
Summaries on
You wont add "Is it the by homeopathy? Ayurveda perhaps" to an article on a new medicine/cure..
Editors/Firehosers note.
http://dilemma.gulecha.org - My philospohical short film.
Hey if nothing else those models would make for great Tshirt designs...
This is good, but few people pay any attention to the other great danger beneath our feet: The earth's magma.
There are many supervolcanoes waiting to happen. With extreme volcanism, much of the life on earth can die. Some people have got the idea that a volcano can destroy an island or a small region, but few people realise that the whole planet (or more specifically its atmosphere, which is what we need most) is in danger of supervolcanoes, and that these phenomena happen from time to time (and we have no way to surely know when the next will hit, it literally hapens under our noses and we know nothing).
We may be able to somehow deorbit a small asteroid, but what about our very own planet? How could we manage all this magma under the ground? We literally live on small islands floating a boiling abyss. We know very well that there are good probabilities that many or all of us will sometime die when some of the boiling magma gets out in a huge explosion and toxicates our delicate atmosphere and hides the sun for years. Yet, there is no public discussion on this topic, no one seems to care, a few smart people have noticed that asteroids must be somehow managed, but I haven't seen many people realising that our very own planet is also a threat that must be somehow managed.
.. with one amendment:
The current inmates become kdawson's guards.I thought the prevailing theory was that it was a comet rather than an asteroid since it left no crater.
Support Right To Repair Legislation.
would be that this is a weapons lab doing this sim. Now, we know roughly what size asteroid can do a LOAD of damage.
So what happens if a country creates a tug and then places it on the back of small asteroid, pushes to earth, and hits major cities? It would be seen as a natural disaster. In fact, if done right, the engines would burn up on the way down. No detection at all. And even the tugs heading out would likely not be detected. By hitting an enemy country with say 3 asteroids at 1x, and having another round coming in for a hit in about 2 months, it would give the country time to surrender and the courses changed, or they would simply take out ALL major cities. Since these are auto-pilot, it is effectively a dooms day machine for the country that it is headed for.
I prefer the "u" in honour as it seems to be missing these days.
1. That there have been far more events in recorded history similar to Tunguska which have been volcanic or geologic in nature than have been due to cometary impact, raising the question of probabilities. --Mt. Saint Helens blowing its top in 1980 is an example, as was Krakatoa in 1983. There was also the 1986 limnic eruption of 1.6 million tonnes of CO2 from Lake Nyos which suffocated 1,800 people in a 20 mile radius. Sometimes it's a methane outgassing which can blow up, (one event was described in the linked paper which damaged a commuter jet plane). The Earth 'burps' on a regular basis. Rocks causing similarly huge events are far less frequent, (as in, there haven't been any at all in the last century).
2. That there was swamp land in the center of the Tunguska caldera. This is a typical place for methane to build up.
3. The directions in which the trees had been knocked down indicated two discrete blast points some distance from one another.
4. There were odd glowing clouds seen over the area in the nights leading up to the explosion which could be explained by methane collecting in the sky.
5. No impact crater was found.
6. No meteorite was found. (--Though there was a concentration of microscopic glass spheres in siftings of the soil and chemical analysis showed that the spheres contained high proportions of nickel and iridium which are often found in meteorites, hinting that they might have been of extraterrestrial origin. But still. . . No rock.)
Every year there are geologic events which result in ash plumes and outgassings all over the world. While there is plenty of evidence of past cometary impacts which had a significant effect upon the Earth, they are all very old; the number of catastrophic events due to impact events over the last century has been pretty much zilch. If we're going to throw Occam at this, (and I am very hesitant in invoking that old and oft-misused saw), then it seems much more probable that Tunguska was the result of a methane outgassing and subsequent explosion. Anyway, the paper is an interesting analysis and it leaves me uncertain as to what to think, as there is still some good arguments for the event having been an impact. I'd be curious if anybody out there has any other info to contribute which might make the picture more clear.
-FL
Because GOD would have sent it!!
Geez!!
Opinion:=TMyOpinion.Create(Me);
What does God need with an Intercontinental Ballistic Missile?
Out of modpoints but really liked a post? 1BDkF6TtmmeZ3yqXbz9yhdYVqRYnwFoXDj
The new simulation which more closely matches the widely known facts of destruction than earlier models shows that the center of mass of an asteroid exploding above the ground is transported downward at speeds faster than sound. It takes the form of a high-temperature jet of expanding gas called a fireball.
Good thing we made the Saving Throw!
Happy people make bad consumers.
IIRC Wardenclyffe never went online. Funding was cut off.
Check out video number 7 at 3.13e+00 seconds to see the Easter egg cartoon that those wacky scientists at Sandia slipped into the simulation! Those crazy guys are having some fun for the holidays!
Funny stuff, guys, way to go! This is the best prank evar!!!!
The man who does not read good books has no advantage over the man who cannot read them. - Mark Twain
have proven that the blast must have been caused by 100,000 tons of TNT. They rigged a massive explosion and counted the number of trees knocked over. This proved conclusively that the Tunguska blast was caused by alien Thetans mining for latinum.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
Doesn't this report completely ignore eyewitness testimony that the fireball "turned" several times?
You think that due to the date, it would be plainly obvious to all and sundry that it was extremely unlikely to be a 'superweapon'.
Okay so in 1908, you could, with enough man-power and resources, have probably built a very tall tower (but perhaps not tall enough) in Siberia, packed it with an inordinate amount of nitroglycerin and touched the whole lot off to create this effect. It would, however, be a little....shall we say....pointless.
In 1908, the necessary technology for nukes was still 30 years in the future.
Ripping an new rectum in the fabric of spacetime.
Is it me (and I only watch the first video, btw) but is there not too much symmetry in that model?
Somethings I'd rather just believe. Sure they show it could have been caused by a small asteroid. But isn't it much more fun to think it could have been a UFO with engine trouble? Perhaps the shadows, Romulans, part of an exploded DeathStar, Heart of Gold, etc.
Think Deeply.
"and why isn't Chicago or London ever destroyed?"
Well I can't speak for Chicago, but London is clearly routinely saved by Doctor Who....
It appears that most asteroids are conglomerates of shale,
What!? I don't know which planetary system you're from, mate, but since shale is a sedimentary rock (formed by compression of layers of mud, clay and silt beneath a body of water), none of the asteroids in this solar system are composed of it.
Some asteroids may be loosely bound accretions of smaller bodies, but we know for a fact that other asteroids (particularly the bigger ones in the belt) are big enough to melt and differentiate, with metallic cores. Some of those in turn suffered impacts which broke off large chunks of pretty damn solid material. (The Barringer meteorite - a chunk of nickel-iron estimated at 150 feet across - left a mile-wide hole in the Arizona desert.)
-- Alastair
Not Semantic Nazi. No one cares about your forest if the trees are alright.
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
Because the gas explosion vaporized the asteroid.
Obviously. (Sheesh!) Guess who's not a rocket scientist here!
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
I've seen the 'natural gas' theory before. It's so contrived that it's almost like science-comedy.
Known as Plan 4 from Outer Space.
They found it
They aren't heroes! They are just regular people who got caught up in a poorly justified military conflict.
Now, the soldiers in Afghanistan, they are heroes.
I'm a Californian, but have worked in Europe, including the UK. Obviously here in the U.S. we have some bad traits .. but if I may comment on the UK, I was struck by how proud people seemed to be that they didn't have technical or scientific skills. I tend to think it's due to the whole class thing, whereby if you're part of the ruling class, then of course you don't have any skills in a scientific or engineering sense.
Despite that, I applaud the UKians (like Turing) who excel anyway!
QUOTE (with minor editing for grammar): 98. December 19, 2007 There is a press-release [at] http://www.sandia.gov/news/resources/releases/2007/asteroid.html on Sandia researcher Mark Boslough calculations of Tunguska. There are some computer graphics, but there is practically no info on physical models on which the calculations are based!
I can say that the graphics resembled [to] me the one in their calculations presented in 1995! And what I read (in his 1995 paper) on the sparse info about the models is not convincing.
Moreover one of the calculations' outcome was a proposal that satellites in orbits are in danger due to 'plumes' from rather small meteoroids ('meteorites')! (see the Boslough's abstract on Tunguska-96 conference here: http://www-th.bo.infn.it/tunguska/abstr3.html ).
Interesting that several groups of researchers using 'the most advanced' computer calculations obtain rather different results! :)
But there is one point [on] which I could agree with Boslough -- the
strength of the forest [destruction] used to be overestimated indeed, but
in reality it should be incorporated into calculations in much more
complicated form than Boslough has done. In my opinion this would alter
the results of the calculations completely. :UNQUOTE
So, why are we getting this rehash of a 12-year-old study now? Could it be the upcoming Centennial?
I have reproduced the same results with my own experiment. A toilet bowl, massive amounts of habenero, processed nacho cheese, high quality chili, and tortilla chips. It was further enhanced by crab cakes, broccoli, and some sausage and egg McMuffins earlier that morning.