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When Comets Attack
Red Flayer writes "Popular Mechanics is running a story that describes one of the more interesting explanations for the Tunguska explosion of 1908: 'Now, a controversial new scientific study suggests that a chunk of a comet caused the 5-10 megaton fireball, bouncing off the atmosphere and back into orbit around the sun. The scientists have even identified a candidate Tunguska object — now more than 100 million miles away — that will pass close to Earth again in 2045.' Note that Popular Mechanics' definition of 'close to' is somewhat different than most people's — the comet will be 3.8 million miles away at its closest. At any rate, the key to this theory is that hydrogen and oxygen in the ice shard exploded upon entering the atmosphere, resulting in the difficult-to-explain blast pattern (previous theories contend that the object must have 'skipped' on the atmosphere and then re-entered at the exact same spot). This would also, sadly, dash the theory that Nikola Tesla was responsible."
I thought I heard this years ago.
The sun's trying to start a snowball fight.
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Tesla, like God, did it. What is it you say? If you don't know there is no way you'll listen even if I tell you the "good news." Obviously, your mind is made up. Tesla did it. I know it and that's good enough for me (and you to if ya know what's good for ya).
It was the great Nikola Tesla who summoned the comet in the first place!
The enemies of Democracy are
This artist's rendition of the explosion graced the back cover of this month's The Planetary Report (from The Planetary Society). It illustrates how the bolide likely blew up above the ground and hence produced no crater. The artist is Don Davis.
One simple rule for its versus it's
Welcome our new comet overlords
I think this is one of the great what-ifs of recent history... what if this event took place in a populated area, rather than in the Siberian woodlands? We still don't know what happened today, so how would people have dealt cognitively with it back in 1908 if thousands or even millions had died?
I find it intriguing to consider.
Do what thou wilt shall be the whole of the Law
Where is the Earth shattering KaBoom????
Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
How can I lower the score on this comment?
For starters, stop posting as AC and get yourself some mod points.
all these comet theories are great, but how to they explain the extra Carbon 14 found in tree rings in that area, for that year? (The trees that hadn't been blown down, of course.)
Source: Encyclopedia Britannica
The Japanese were well aware of what had happened to Hiroshima and Nagasaki. They had people working on an atomic bomb as well but they were barely scratching the surface of what needed to be done as they just did not have the industrial capacity.
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Obviously, this proves that Tesla did it. He had a number of theories about radiocarbon14 waves, you know. That big antenna he was working on, probably could have altered the carbon.
This is my sig.
It was shown back in 1966 that the butterfly shape of the fallen trees may be caused by the several explosions combined with the ballistic wave.
The Russian researchers built a model of the site (1:10000), with explosion modeled by an explosive cord with an explosive charge at the end. The forest model was built from the tiny flexible wires with plastic crowns.
They have shown that placing the cord at some inclination angle (close to 30 degrees) the impact shape was clearly resembling the butterfly shape of Tunguska event.
The abstract (in Russian) is here:
http://tunguska.tsc.ru/ru/science/conf/1966/zotkin/
The FA talks about the comet having a 'host planet' around which it orbited long enough for the 'host planet's' magnetic field to electrolyse the water in the comet into hydrogen and oxygen. It was the ignition of the hydrogen that is claimed to have causes the explosion. Possible of course but it seems a bit of a stretch to me. Occam's razor and all.
It was me, that day I had 2 bean burritos, and happened to be in the area when I had a major attack of gas. And the extinction of the dinosaurs that was me again. I really need to stop it with the bean burritos but they are just so damn good.
Suppose the impactor is a comet. Approaching any collision with the Earth, it will have a velocity of about the Earth's escape velocity or even exceeding that.
OK, using liquid H2 and LOX, why don't we build single stage rockets that are able to reach Earth escape velocity? Because orbital velocity let alone escape velocity gives an object a kinetic energy that is large compared to the chemical energy in the hydrogen-oxygen bond. That means a rocket using H2 and LOX as propellant requires most of its mass as fuel, and it needs to impart the energy from that fuel it is rapidly discarding by burning and ejecting it on the tiny remaining mass fraction that is the space craft.
That means that the kinetic (.5 m v^2) energy of the impactor will far exceed any combustion energy of some small mass fraction of hydrogen and oxygen bubbles embedded in an icy substrate.
Which means that any combusting hydrogen will be hardly noticed in the much larger explosion from the kinetic impact of whatever (asteroid, comet) it was.
By the way, it is generally understood that most meteors are cometary and most meteorites are asteroidal. Even though comets put on a big gassy show, the Earth encounters vastly more asteroidal objects big enough to make it to ground level than comets (or explode over Tunguska). On the other hand, the few comets (compared to asteroids) that encounter the Earth are like hairy dogs that shed all over wherever they have gone (their orbital ellipses), and their detritus, the cometary dust grains, form the common meteors seen at night.
We constantly hear this. The [Japanese, Germans] did not have the industrial capacity to [develop a nuclear bomb, train pilots, build warships]. Well, why not? The U.S. developed the nuclear bomb with talent plus a tiny fraction of its industrial capacity. Japan and Germany each had more than half the U.S. population. Why were they so feeble?
And don't give me a bunch of crap about free enterprise. Keep it real.
Sandia Labs (the same group that does nuclear simulations) did work on this several years ago. They produced some excellent simulations of asteroid explosions, and their effects in the admosphere and on the ground.
A summary with some great videos is posted here:
http://www.sandia.gov/news/resources/releases/2007/asteroid.html
I would think that if a comet was close enough to earth to bounce off it, that it would have been quite large to the eye, and LOTS of people would have seen it. A simple google query reveal no mass sightings of a comet, which are typically visible for weeks at a time.
A large flash was seen, but no precedent reports of any significant comets.
OK I guess it could be a really, really tiny comet.
..........FULL STOP.
Does anyone recall the the interviews done of the people in the area after the blast.
There was a reporter/documentarian that went over there and talked to the locals.
They talked about a metallic cavern 150 miles away from tunguska that was persistently radioactive.
The older guys talked about it shooting plasma balls into the sky after they noticed it charging up for a month. And they noticed this because it would kill off more stuff around it.
Mainly, it looked like a defense grid that had the nasty side effect of irradiating everything within 20-80 meters. All the wildlife and grass around it died- and the people apparently did the first couple times as well.
I can't remember what reporter documented this though. Do any of you older guys recall seeing this maybe 15 years ago? It was an ancient defense grid that was basically a radioactive capacitor(magma sourced?) that vaporized incoming asteroids. It's ok if you don't. Just thought I'd throw that out there, since considering other physical impossibilities apparently is.
It still doesn't account for the Carbon 14, which is real, and which indicates radiation that a comet strike would not explain. The theory advanced by the Britannica (it was an older set) was that a chunk of antimatter about the size of a baseball had hit the atmosphere at very high speed. That could account for both the explosion and the radiation.