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Print 48 comment(s) - last by MarthaGray22.. on Feb 17 at 9:24 PM


  (Source: RT.com)
It exploded around 9:20 a.m. local Moscow time

A meteor exploded in the sky above Russia early Friday morning, shattering the glass of thousands of windows and leaving many citizens injured.

The meteor, estimated to be about 10 tons, entered the Earth's atmosphere traveling at 33,000 MPH and exploded around 9:20 a.m. local Moscow time. The explosion occurred over Russia's Urals region about 18-32 miles above the ground.

According to Chelyabinsk health chief Marina Moskvicheva, about 985 people in the city of Chelyabinsk alone required medical assistance. Approximately 110 of them have been hospitalized, and about 159 of the injured were children. This doesn't include other possibly injuries in other cities.

The Emergency Ministry said 20,000 rescue workers have been mobilized.

Vladimir Stepanov of the National Center for Emergency Situations at the Russian Interior Ministry said about 270 buildings have been damaged due to the explosion, where most of it consists of broken glass. Hospitals and schools are some of the buildings affected.

Another report from RT.com said 3,000 buildings alone were affected in Chelyabinsk, where shattered window glass measured 100,000 square meters.

The Russian space agency Roscosmos said that one meteroid entered the atmosphere and burned into meteorites that spread across three regions in Russia, including Chelyabinsk. Some were believed to be scattered in neighboring Kazakhstan as well.

Check out this video, which shows the meteor nearing the ground and exploding:

Sources: RT, Huffington Post



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By 91TTZ on 2/15/2013 12:36:39 PM , Rating: 4
The media is reporting that the meteor "exploded" because of the loud boom that was heard. However this is not correct.

The meteor entered the atmosphere and eventually broke into pieces and burned up. The loud boom that you heard was the sonic boom from the meteor traveling through the atmosphere at supersonic speeds. You also hear smaller sonic booms immediately afterwards caused by the shockwaves of the meteor fragments passing by. The damage that occurred was caused by the overpressure from the sound wave. It's no different than if a supersonic aircraft passed overhead.

Here is a video of the Concorde passing over the ocean:
https://www.youtube.com/watch?v=annkM6z1-FE

You'll notice that the Concorde passes overhead and you can't hear anything until the shockwave reaches the ground, with the characteristic "sonic boom". That's because it flies at up to 60,000 feet. If it was flying supersonic any lower it would shatter windows and damage buildings.

This is what happens when a smaller aircraft flies supersonic over buildings:

https://www.youtube.com/watch?v=podqKi-q04w

Watch it in HD. Notice how it blows out the windows in that building. These pilots made a mistake.

Judging by how long it took for the shockwave to reach the ground after this meteor passed overhead gives you a pretty good idea of how far away it was. And seeing how much damage it caused should give you an idea of just how powerful it was and how much damage it could have caused if its trajectory caused it to travel at a lower altitude.




By 91TTZ on 2/15/2013 2:46:45 PM , Rating: 3
Traveling supersonic is exploding? So the Concorde exploded overhead in my video? Those Brazilian Mirages exploded?


By ChronoReverse on 2/15/2013 2:53:02 PM , Rating: 2
The meteor broke up and maybe astronomers call that "exploding" but the point made here was that the "boom" wasn't the sound of the breakup/explosion but rather just the sonic boom of a large massively hypersonic object.


By geddarkstorm on 2/15/2013 5:10:07 PM , Rating: 2
Yes, the meteor breaking into fragments like that is called exploding in astronomy, that is the correct term/description for the event.

Gotta get used to jargon and not over think jargon vs. common usage of words.


By johnsmith9875 on 2/16/2013 4:19:10 PM , Rating: 2
Well if the meteor was made of a mix of carbon dioxide snow, ice and rock, then definitely it would explode because the internal pressures from the heated steam would make it literally explode.


By augiem on 2/15/2013 5:07:42 PM , Rating: 2
The news reports I read all mentioned the sonic boom. I didn't see any attribute the shattered glass to the shockwave of an explosion.


By ChronoReverse on 2/15/2013 5:13:19 PM , Rating: 2
Perhaps it's been corrected but most news sources this morning attributed the boom to the explosion rather than the sonic boom (e.g., CNN, National Post)


By augiem on 2/15/2013 7:45:07 PM , Rating: 3
Hmm... Just found this:

quote:
The blast released energy comparable to a 300- to 500-kiloton nuclear warhead, says Bill Cooke, who heads the meteoroid environment office at NASA's Marshall Space Flight Center in Hunstville, Ala. By Comparison, the Nagasaki nuclear bomb had a yield of 20 to 22 kilotons.


Source: http://www.csmonitor.com/Science/2013/0215/Russian...


By augiem on 2/15/2013 8:14:28 PM , Rating: 3
After reading more about the meteor, I don't think your analysis is correct.

This explosion had 20-33 times the energy of the Little Boy dropped on Hiroshima (300-500 kilotons vs 15). According to estimates, the major exlposion/breakup occurred at an altitiude anywhere between 12 and 32 miles high (Nasa said 12-15, Russia said 19-32), compared to 1,968 ft at Hiroshima. At the low end of the estimate, that's 63,360 ft high -- 3,000 feet higher than the Concorde's maximum cruising altitude. At the high end of the esitmate, that's 168,960 ft -- the top edge of the stratosphere.

Had this thing broken up closer to earth, we could have seen some major damage.

Now if the articles I read are misinterpreting NASA's words and and the total energy of the object was 300-500 KT, then maybe I'm wrong.


By augiem on 2/15/2013 8:15:36 PM , Rating: 2
Forgot the point: That kind of explosion is going to make one heck of a shockwave and sound.


By 91TTZ on 2/17/2013 1:16:31 PM , Rating: 2
What you're seeing is the media incorrectly reporting what they've heard scientists saying.

The figure they gave for the "explosion" is actually the figure for the kinetic energy of the meteor. Basically it's just mass x velocity. Since it obviously came to a stop it had to dissipate all that kinetic energy in the atmosphere. It doesn't mean that it exploded.


By tng on 2/15/2013 10:01:31 PM , Rating: 2
I grew up in an area that was near a Air Force training range and we got sonic booms practically everyday. It would rattle windows and as kids we thought it was cool.

I think that most of what we heard was from F-102s, that were pretty long in the tooth even then. We rarely saw them in the sky, but the booms would give them away even though we could not hear the engines.

This meteor was a completely different aerodynamic profile (if you can call it that) than a plane, moving at literally Mach 40+, so I could imagine that the sonic boom was much more forceful for that reason.


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