WOW! Just wow....
 

Obviously, the "shot down" is totally wrong... Local news coming up is going to cover the story. I haven't see anything yet about what altitude it was at.

[YOUTUBE]PXFq-RWdpnI[/YOUTUBE]

[YOUTUBE]TtOL5OiWTNI[/YOUTUBE]

ETA: Local news gave it 15 seconds, and not even a tie-in with the asteroid close encounter on the morrow. :davieddy:

Allegedly this may have been a little buddy of the 50m asteroid making a close flyby [url=http://www.bloomberg.com/news/2013-02-07/asteroid-s-earth-fly-by-will-traverse-satellite-zone-nasa-says.html]later today[/url]. Cool stuff.


NYT breaking news piece [url=http://www.nytimes.com/reuters/2013/02/15/world/europe/15reuters-russia-meteorite.html?ref=world&_r=0]here.[/url]

Here is a 1080p version of the first video you linked. It looks really spectacular:

[YOUTUBE]7c-0iwBEswE[/YOUTUBE]

We don't know yet, and possibly it will never be completely clear what would have happened without the intervention, but the Russian forces may have successfully prevented a much worse tragedy here than has actually occurred. If so, this is very well done.

My immediate thought is: thank goodness this didn't happen 25+ years ago when (1) the threat of rocks from outer space was not taken anything like as seriously as it is now, and (2) the Cold War was at its height and the US and Russian leaders had their itchy fingers hovering over the launch button of their nuclear warheads.

[QUOTE=schickel;329559]Obviously, the "shot down" is totally wrong... Local news coming up is going to cover the story. I haven't see anything yet about what altitude it was at.[/QUOTE]NBC's science [URL="http://cosmiclog.nbcnews.com/_news/2013/02/15/16969092-400-injured-as-meteor-fireball-screams-across-sky-in-russia?lite"]blog[/URL] reports the explosion as happening at 10KM (32,800 ft), along with as many as 400 injured, 3 seriously.

Check out the 4:45 YT video on the blog; some amazing footage from street level when the shockwave from the main explosion hit.....I imagine we can look forward to more being posted throughout the weekend. Will also be interesting to see if reports of debris hitting the ground are substantiated.

Livejournal [URL="http://zyalt.livejournal.com/722930.html"]page[/URL] with more videos and stills....

The Dutch news journal NOS took its time to drop the military intervention fable, but it has done now. I was going by that in my previous reaction. Presumably some reporter assumed that the rock must have been fired at since it split into fragments, not realising that the tremendous air resistance can and often does cause this to happen to impacting bolides.

here, BBC article
[url]http://www.bbc.co.uk/news/world-europe-21468116[/url]

How big would a meteorite have to be to make it all the way to the ground?

(Assuming it is coming straight down to minimize air resistance.)

:snake1:

[SIZE="1"][COLOR="White"]No one would have believed in the early years of the 21st century that our world was being watched by intelligences greater than our own; that as men busied themselves about their various concerns, *they* observed and studied, the way a man with a microscope might scrutinize the creatures that swarm and multiply in a drop of water. With infinite complacency, men went to and fro about the globe, confident of our empire over this world. Yet across the gulf of space, intellects vast and cool and unsympathetic regarded our planet with envious eyes and slowly, and surely, drew their plans against us.[/COLOR][/SIZE]

[QUOTE=Xyzzy;329587]How big would a meteorite have to be to make it all the way to the ground?

(Assuming it is coming straight down to minimize air resistance.)

:snake1:[/QUOTE]
Depends on all sorts of factors, including its speed relative to the Earth, its composition (this can be hard iron or softer silicate with various gradations), and its angle of entry (affecting the distance travelled through the atmosphere.

Depends of the size you want it to touch the ground.

[QUOTE="http://news.yahoo.com/possible-meteor-shower-reported-eastern-russia-052833588.html"]"There have never been any cases of meteorites breaking up at such a low level over Russia before," said Yuri Burenko,[/QUOTE]


if tunguska's 5-10 miles is to be counted that suggest under 5 miles up.

Now [I]that[/I] is something that doesn't happen every day!

no, but it's not a rare occurence
[url]http://www.guardian.co.uk/news/datablog/interactive/2013/feb/15/meteorite-fall-map[/url]
Every meteorite fall on earth mapped; or at least those we know about.

Clearly The Matrix has been raptured due to a Mersenne prime being found while George wasn't on vacation.

I'll have to admit: when I first saw the topic title, I thought Curtis Cooper had [strike]discovered[/strike] decided to reveal another Mersenne prime. :P

[QUOTE=science_man_88;329592]if tunguska's 5-10 miles is to be counted that suggest under 5 miles up.[/QUOTE]Not really. If the 1908 event was from a stony asteroid it would have broken up much lower than if it were a fluffy comet. I've read several papers on the subject; AFAIK there still isn't too much of a consensus though the latest I'd heard (still several years ago) was that it was probably stony.

Stony. Irony. Maybe even holey! :rolleyes:
[QUOTE]Robin: Holey rusted metal, Batman!
Batman: Huh?
Robin: The ground, it's all metal. It's full of holes. You know, holey.
Batman: Oh.[/QUOTE]

I was interested to note that the Tunguska Event Wikipedia page has already been updated with mention of today's happening.

Now the [url=http://www.buzzfeed.com/ktlincoln/what-do-the-meteor-and-north-korea-have-in-common]conspiracy theorists are out in force[/url].

What's the name of the song in the 1st video from 45-53 seconds?

Note how popular the video event recorders are in Russia these days (compare the size and detail in the [URL="http://ru.wikipedia.org/wiki/%D0%90%D0%B2%D1%82%D0%BE%D0%BC%D0%BE%D0%B1%D0%B8%D0%BB%D1%8C%D0%BD%D1%8B%D0%B9_%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE%D1%80%D0%B5%D0%B3%D0%B8%D1%81%D1%82%D1%80%D0%B0%D1%82%D0%BE%D1%80"]Russian wiki entry[/URL] and the English general article on EDRs). Sort of stems from the instant popularity of infamous videos (see Utube; there are zillions of them) of the police abuse or extortion for imaginary violations.
It is possible that every other car has them (even if the whole car is cheaper than the camera:smile:).
Even in Chelyabinsk!

[QUOTE=Xyzzy;329587]How big would a meteorite have to be to make it all the way to the ground?[/QUOTE]

It depends what you mean by 'all the way'. It's not going to land gently on the ground in any case, it's got enough kinetic energy to heat itself to well above boiling point - orbital velocity gives a kinetic energy equal to twelve times the object's weight in TNT, and it has to lose that pretty much between the top of the stratosphere and ground level.

Looking at the video, the thing comes in glowing white-hot and constantly brightening, and then there's the flash significantly brighter than the Sun which I think corresponds to the point of maximum deceleration - I suspect that's when the asteroid tumbled into a particularly unaerodynamic position. The 'contrail' of vaporised and condensed rock stops at that stage because the rock had stopped boiling; it's still glowing hot and surrounded by plasma when it leaves the camera frame.

I do hope someone got a high-altitude aircraft (a MiG-25 would work well if they had one around) with sampling equipment up to the vicinity of the trail before high-altitude winds blew it away.

The hole in the ice on the lake a hundred miles further down the track is produced by a rock falling not much faster than had it been dropped from an airliner; the asteroid had broken into pieces and the pieces are moving at the terminal velocity of a large rock in air, which is still enough to make a mess.

If an asteroid came straight down, it would punch through the atmosphere in a couple of seconds and still have quite a lot of its decent atom-bomb's worth of energy at ground level. Which would be unfortunate for anyone at ground level.

[QUOTE=firejuggler;329609]
Every meteorite fall on earth mapped; or at least those we know about.[/QUOTE]
I wonder why no meteorite felt into the ocean.... :confused::unsure::whitsle:

[QUOTE=LaurV;329715]I wonder why no meteorite felt into the ocean.... :confused::unsure::whitsle:[/QUOTE]A while back I saw a day-time bolide (that I reported). That if it survived would have landed in the ocean.
I knew where I was standing to within a about 5 feet on the north-west axis and I ranged ~15' on the east-west axis. I was looking through some clerestory windows, so I had a confined viewing angle.

[QUOTE=fivemack;329663]and then there's the flash significantly brighter than the Sun which I think corresponds to the point of maximum deceleration - I suspect that's when the asteroid tumbled into a particularly unaerodynamic position.[/QUOTE]

... or the point where the asteroid fragments and the pieces suffer greater combined drag than the complete thing did, along with greater surface area to emit light.

[QUOTE=akruppa;329916]... or the point where the asteroid fragments and the pieces suffer greater combined drag than the complete thing did, along with greater surface area to emit light.[/QUOTE]
Which is better for the people on the ground, the asteroid exploding near the ground, or hitting the ground nearly intact?

And I'm asking from a survival perspective, not a scientific perspective, if you get my meaning.(since, technically, even a survival analysis requires science. The scientific perspective would mean the scientists studying it were happier, even if people affected by it weren't)

[QUOTE=jasong;330178]Which is better for the people on the ground, the asteroid exploding near the ground, or hitting the ground nearly intact?

And I'm asking from a survival perspective, not a scientific perspective, if you get my meaning.(since, technically, even a survival analysis requires science. The scientific perspective would mean the scientists studying it were happier, even if people affected by it weren't)[/QUOTE]

From a logical point of view, I would say hitting the ground would be more survivable, but only by degrees. The atom bomb dropped on Japan detonated at ~2000 feet IIRC, which caused far greater damage from the shockwave then if it had exploded at ground level.