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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."
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
In Soviet Russia, the forest flattens the asteroids!
I welcome our new asteroid overlords.
Imagine a beowulf cluster of those!
The CB App. What's your 20?
Everybody knows it was Santa crash landing
This one they didn't notice until after it nearly missed earth.
So to answer your question: Yes, it's very possible!
09 f9 11 02 9d 74 e3 5b d8 41 56 c5 63
Imagine a world where a small asteroid fragment or comet had struck Russia 60 years after Tunguska - during the depths of the Cold War. It would be a very different world today indeed.
khasim (12/9/06): In a blind taste test, more people preferred Coke over the Pepsi that I had previously pissed in.
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?
I'll grant you that they do not explode in the traditional TNT/explosives sense of the word. However, falling space debris can indeed "explode" when entering the atmosphere. As they push deeper and deeper and the air gets thicker, it presents more and more resistance on the falling object. Eventually, the wall of air becomes so dense that the action-reaction forces break the falling object up. Violently. Combine that with the fact that the asteroid/comet/meteor and surrounding air has been heated significantly due to friction, and you get a fireball and a tremendous shock wave in the air.
To test this premise, I recommend throwing an egg or three at the front door of your local police station, as hard as you can. You will see that (among other things) the egg does indeed explode.
khasim (12/9/06): In a blind taste test, more people preferred Coke over the Pepsi that I had previously pissed in.
Free American English Lesson: Adverbs modify verbs.
...Grammar Nazis, please keep walking. :)
Verb in the Subject Sentence: Missed (past tense)
Context: This asteroid was very near to Earth when it missed us.
Adjective: Near (adverb form: nearly)
Thus: The asteroid nearly missed Earth.
Your sentence gets a thumbs up by me!
khasim (12/9/06): In a blind taste test, more people preferred Coke over the Pepsi that I had previously pissed in.
Nothing to see here! Move along!!
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?
1) A small black hole
2) A tiny bit of antimatter
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.
42, It was a giant cum shot from god. Bye karma. I wish I could think of shit insightful to say.
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 nearly HIT earth. The problem with the sentence is the verb, not the construction.
Dude, I think I can see my house from here.
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."
Yeah, Chuck Norris showed up...
Navicula hydraulica plena anguilarum est. Omnes castelli tuus nostri sunt. Ed elli avea del cul fatto trombetta.
It'll just probably break some windows and throw some chairs around.
You don't know what you don't know.
"What else would it have been?"
The theory I've heard a few times was that it was anti-matter. Doctor Raymond Stanz, however, postulated that it may have been the result of a dimensional crossover. This theory has not been widely accepted, though, because no P.K. readings have been captured to support this claim.
"I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)
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
to destroy the Arachnid threat.
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.
Asteroid or Hammeroid?
Don't be apathetic. Procrastinate!
This is what happens when you cross the streams. DON'T CROSS THE STREAMS!
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.
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
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.
3)Something else = ???
4) Profit!!!
There Fixed that for you.
To have a right to do a thing is not at all the same as to be right in doing it
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
They found it