Sat Feb 16, 2013, 02:46 PM
WillyT (72,631 posts)
Best Footage Of Russian Meteor Strike I've Found So Far !!!
And from the San Francisco Chronicle:
The largest recorded meteor strike in more than a century entered the Earth's atmosphere about 9:20 a.m. local time at a hypersonic speed of at least 33,000 mph and shattered into pieces about 18 to 32 miles high, the Russian Academy of Sciences said. NASA estimated its speed at about 40,000 mph and said it exploded about 12 to 15 miles high, released 300 to 500 kilotons of energy and left a trail 300 miles long.
"There was panic. People had no idea what was happening," said Sergey Hametov of Chelyabinsk, about 930 miles east of Moscow in the Ural Mountains.
"We saw a big burst of light, then went outside to see what it was, and we heard a really loud, thundering sound," he said by telephone.
The shock wave blew in an estimated 1 million square feet of glass, according to city officials, who said 3,000 buildings in Chelyabinsk were damaged. At a zinc factory, part of the roof collapsed.
The Interior Ministry said about 1,100 people sought medical care after the shock wave and 48 were hospitalized. Most of the injuries were caused by flying glass, officials said.
Authorities believe an estimated 7,000-ton meteor that created a panic in Chelyabinsk, Russia, crashed into nearby Chebarkul Lake and produced this circular hole. Photo: Associated Press
22 replies, 4264 views
Best Footage Of Russian Meteor Strike I've Found So Far !!! (Original post)
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Response to jsr (Reply #1)
Sat Feb 16, 2013, 02:55 PM
customerserviceguy (17,301 posts)
3. I'm thinking that icy lake would have cooled it down pretty quickly
I would imagine there are plans in the spring to try to look for it. It might teach us something about meteorites, since I would suppose that most are found cooled down slowly, and may have had a chance to rearrange themselves, chemically speaking.
Response to TheMadMonk (Reply #12)
Sat Feb 16, 2013, 06:23 PM
eppur_se_muova (26,189 posts)
16. Greenlandic and Antarctic ice is to meteorites as amber is to insects.
It can collect meteorites for thousands of years, then a change in weather or climate erodes the ice and suddenly there are meteors lying all about.
Next best: sandy deserts, which bury fresh falls only to reveal them years, even centuries, later.
Response to customerserviceguy (Reply #3)
Sun Feb 17, 2013, 02:05 AM
Posteritatis (18,807 posts)
22. They're actually somewhere between "cool" and "really cold" on impact generally
They spend five billion years at -270 degrees and only about ten to thirty seconds at high temperatures in the atmosphere; during a lot of that the outer layers are rapidly ablating off and the rock is cushioned somewhat by the air (which is what's really heating up on the way down). After it gets out of the "Hi, I'm a fireball" stage it's "only" moving a few times the speed of sound usually in the last few seconds before hitting the ground. There's very little opportunity for the meteorite to actually heat up in all of that; when they come to a stop they're usually warming up to ambient, not cooling down to it.
There was actually someone who got directly tagged by one a few decades back, being lucky enough that the atmosphere (and the top two floors of her house) slowed it down a great deal. She was badly bruised - think "beaned with a baseball made of iron" - but not burned.
Response to Logical (Reply #18)
Sun Feb 17, 2013, 01:24 AM
countryjake (8,118 posts)
20. They're now saying the lake wasn't an impact site...
18:40 GMT: The search for the meteorite parts at Chebarkul Lake and at other two locations has officially been stopped. The huge ice hole found at the lake on Friday has formed because of a different reason, the Vice-Governor of Chelyabinsk region Igor Murog told Interfax-Ural.
07:58 GMT: No meteorite fragments were found at the bottom of Chebarkul Lake, says the Emergencies Ministry. A lack of underwater visibility, as well as a thick up to 1.5 meters layer of ooze were cited as the main reasons for failure. Six divers spent three hours searching for solid objects in the mud but finally gave up. Water samples taken from the lake have also shown nothing unusual.
I'm not sure what that Vice-Governor meant, but it sounds like the divers just gave up.