Wow, wow, wow.

So like I heard on the weather station that it wasn't gonna rain after all and I says to my buddy, "Hey, let's go hit the beach after work!" and he says okay, so we get our trunks and stuff and head out to the beach and then when we got there it was thundering and lightning to beat all get out, rain coming down in buckets, and when we finally got back I called the weather station and asked the guy what was that about? and he says, "Dude, that was different rain."

more video

Don't have to work today, and coincidentally turned the news channel on. Amazing. They're getting more and more amateur videos all the time. Some security videos showed the effects of the pressure wave from inside buildings -- windows blown in, heavy steel doors thrown off their hinges. And this from a lump of ice half a meter across.

Not sure why. May I offer the gnomes some leftover birthday cake and some chai?

The near miss asteroid is 50 metres across, isn't it, not 500m.

Right. Fifty meters. Correction to be made.

Should Pope Benedict change his mind about resigning?

Bill Higgins @8: No, it's a harbour gun. God wants Benedict to proceed to sea without further delay.

Bad Astronomy is all over this.

It may be instructive to search Youtube, or other sources, for челябинск метеорит ("Chelyabinsk meteorite") or variations on that string.

(As the Bad Astronomer pointed out, beware of pranksters who show you the Door to Hell in Turkmenistan. It's an amazing sight, but it has nothing to do with the meteor.)

As Charles Stross pointed out on Twitter, if this had happened 30 years ago we'd all be dead or dying by now. Video via the Guardian website here shows (at 0:12) what the bang and tinkling glass sounded like.

And how interesting it is to see our tacit assumptions about incident-spectator safety totally undermined. Many news reports of the last few decades (Challenger, 9/11, Columbia) have shown us people looking up at streaking objects or their vapour trails; we have concluded that if the vapour trails point Elsewhere we are safe; these meteorite videos provide a counterexample.

At the start of Rendezvous With Rama, vast numbers of folk not killed by the meteorite have their hearing permanently damaged. Having seen videos such as these I can grok it.

I posted something that had both a Wikipedia URL and also a string of Cyrillic characters.

Perhaps the gnomes would like a steaming bowl of borscht?

Introductory video now "removed by user."

Proof that we live in the era of awesome data: interactive map from The Guardian showing every known meteorite strike

"It's the end of the world."
- the town drunk in 'The Birds'

To quote my father here, "bozhemoi!".

Youtube appears to be staggering -- not just the meteor video, but all videos seem to be stalled indefinitely.

There are plenty of videos to replace the one I originally posted. Amazing. Scary.

Teh Kwazy is already at work; a Russian of the Liberal Democrat (actually far-right nutty) Party has declared that the meteor was an American weapon, and that it was intercepted by the Russian military.

Here is a good compilation of clips:

http://www.youtube.com/watch?feature=player_embedded&v=90Omh7_I8vI

The shot of the ground from a building, showing shifting shadows from the brighter-than-daylight meteor passing overhead, is particularly effective.

pericat 2: "Dude, that was different rain."

Different...rains every time. Different...rains.

JennR 18: To quote my father here, "bozhemoi!".

My mother would say "Jesusmaria!" (pronounced YEHZH-oosh-MAHD-ee-ya)

http://zyalt.livejournal.com/722930.html

This guy's been gathering videos. Largest collection of them I've seen so far.

Re: soviets 30 years ago, explosions in the sky, e
It's probably safe to assume that a flash of light in the sky brighter than the sun is Nothing Good, and finding a large, sturdy object to take cover under might be a good idea. However, I'm not sure it would occur to me to duck and cover if I saw something like this in time for it to matter.

However, this looked nothing like what a nuclear air burst would look like. It was also moving faster than an ICBM would. I would like to think that the Soviets, 30 years ago, would have been able to tell the difference between a meteor and a nuke.

(For point of reference, this is what a nuclear air burst looks like: http://www.youtube.com)/watch?v=yOwH55lnA8M.)

I'm just boggled by the initial video posted in this thread; if I'd been the one driving that car, I'd either be (voluntarily) on the side of the road by the time it ended, or (involuntarily) in the ditch from shock. Either way, I'd not be driving calmly down the street as the video ends. (Anyone speak Russian? I don't know if that's the car radio in the background or the person/people in the car, but I'm kinda curious what was said....)

See, if this happened in the US House of Representatives, it would be some bozo Tea Partier demanding a response in all seriousness.

I'm glad to see the CANADIAN Parliament still has a sense of humour.

Arrrgh. Wrong thread. Sorry.

Cygnet@24: yes, it's unlike a nuclear airburst in many ways, but it's close enough that in a time of high tension (say, during Able Archer 83), one can imagine local soldiers and airmen making panicked calls up the chain of command containing words such as 'vapour trail' and 'blinding flash'. Some of these calls could have ended with a loud bang and the sound of a telephone kiosk being demolished by a shock wave. If the military were already on high alert things could get very nasty very quickly.

There's been a report of a meteor over southern Cuba. Are we having a meteor epidemic?

Reports of large tripods walking cross-country just south of Sosnovka and Sovetskiy were denied by local officials immediately before all contact was lost with the area.

@25 Xopher
Laughter is the only appropriate response to the party presently in power here, I'm afraid.

Lars... Uuuuuuulaaaaaa!

Thank you, Serge. Someone had to say it.

Debbie @4 I suspect the gnomes got activated by your two-word phrase that begins with a word meaning non-professional and ends with a word related to audio but including visuals as well. It is my understanding that this phrase is often used to entice the unwary into viewing people in various states of undress, among other things. The gnomes may thus have deemed your note a potted meat product.

One take-away from the videos? Do remember that the speed of the pretty, pretty light ≠ speed of shockwave.

Doug @33 -- bet you're right, in retrospect. I'm just as happy to share treats with the gnomes as try too hard to second-guess the filters, though.

Dang it. Forgot to switch my name. Wintercakes and coffee?

Exactly right, Doug (& Debbie). The term "amateur video" draws our attention.

In the unlikely event that such an object were to appear over my home city would it be a reasonable response to hurry outside and cover ears? Or would it be significantly safer to take shelter in an interior room with no windows?

I guess I'll have to hurry up with Trauma and You Part Six: Explosions.

I'd say, Stay Away from Windows, make yourself one with the ground, in a shallow ditch if possible, face down, head toward the fireball. Put thumbs in ears, fingers over eyes, and open your mouth until the shockwave passes.

All it takes is about 15 psi overpressure to be potentially fatal.

Why was the 50-meter asteroid supposed to miss hitting Earth by 15 minutes? (I didn't want to watch the video, didn't see any text.) I would have thought they'd measure the distance in miles.

They did. It was 17000 miles. Apparently that's closer than some GPS satellites.

Geosstationary orbit is about 22000 miles out.

Whew! Link.

#40 Maybe they meant it in the sense of "if Earth had been 15 minutes further along in its orbit"?

Stefan, that's what I was getting from it.

I was somewhat amused by all the people who think we can actually do something to prevent being hit by an asteroid, even a very small one.

It may have vanished in the move, but I remember reading a pamphlet from WW2 on how to adapt a home as an air-raid shelter. Things like how much brick was needed to stop a bullet (rather more than one wall's thickness) and what sorts of space were least likely to collapse.

The key was ground floor spaces which were narrow and without windows, such as a hallway.

I know American domestic architecture can be very different to what is seen in Europe, but I would think the basic principle would hold. One change has been the use of toughened glass for doors, far less of a risk than the usual window glass.

The warning time between the flash and shockwave was about two minutes. The explosion altitudes were between 70km and 30km, and estimates of total energy release are about 500 kilotons. There were apparently three distinct explosions.

As a practical problem, the chances of this happening to your locality are so slight that whatever you think of doing will likely be forgotten before you experience such a situation.

PJ Evans @ 45... But damned if we shouldn't try.

This reminds me it's been a long time since I've seen 1998's "Deep Impact". Hey! That's pre-LoTR Elijah Wood!

P J, I've heard some fairly credible stuff that suggests we can. Remember that the asteroid motions are known years in advance, so we have a lot of time to divert an asteroid just enough to keep it from killing us all.

As Xopher implies: a small diversion very early makes a big miss possible. That's part of the joy of working with great distances! The three-body problem may not be generally solvable, but it is possible to predict what a given bump will do to an asteroid at a couple of years out....

The Astronomy Picture of the Day for today is a video montage of the meteor, from various locations.

Tom Whitmore@49: back-of-the-envelope calculation funtime... Wikipedia quotes an estimated mass for the Russian meteor of 10,000 tons (10⁷ kg), and a Space Shuttle SRB can produce 10⁷ N of thrust, actually a bit more, for 100s. So we could have given this rock 1 m/s² acceleration sideways for 100 seconds. More than enough to get it out of the way. Space defence is easy once you've identified the tiny dark target several years in advance and performed a very difficult rendezvous with it in space.

If we actually knew about everything that was floating out there it'd freak us out. I found this very pretty HTML5 planet-and-minor-planet simulator the other day which gives a nice picture of how the bigger stuff moves. Most of the stuff out there will never hurt us, but ranking the risks associated with the things that might is a nasty task. If last week's rock had been a little bigger, we might have wanted to decide between nudging it away and evacuating Chelyabinsk Oblast.

Xopher Halftongue @48: I recall reading some 'asteroids' may be more like flying piles of gravel than solid rocks. Which would be more of a problem to nudge. Probably not impossible, but would require more preparation (and the ability to distinguish which was which with enough advance warning).

Rob Rusick @52: My first-impression hunch would be that with a pile of gravel (and maybe even with a solid rock, if you can manage to break it into a pile of gravel), you might not need to deflect it all away from the Earth, as long as you dispersed it across a large enough portion of the Earth's surface. If the Chelyabinsk object had been spread out in pebble-size pieces across the Earth, I would imagine they'd all have vaporized very quickly, and just added a little to the temperature and dust density of the upper atmosphere; we probably wouldn't have been able to observe any change.

I remember when AIP released Meteor, the film that bankrupt the studio, someone reprinted the MIT report that it was based on as a paperback. As I remember it, the idea was to replace the Command Capsule (and the bay the LEM lived in) with a Hydrogen Bomb. Considering that it would violate the 1964 Nuclear Test Ban Treaty as thoroughly as the ORION project would have, I admit to a certain amount of skepticism without a hell of a lot of lead time to negotiate a loophole and find a launch vehicle.

Asteroid diversion notions have moved pretty far beyond "nuke it."

Ideas I've read about recently include zapping them with lasers to produce gentle thrust, and making repeated passes with a LARGE ion drive propelled spaceship.

The latter would use the ship's gravity field to very gradually shape the asteroid's orbit.

And while I didn't read the article, a recent suggestion involved paint.

Stefan Jones (55): Okay, I'll bite: paint?

Mary Aileen (56): paint one side white to increase reflectivity, acting as an immensely crude solar sail.

56/57
I wonder how much and what kind of paint would be used. Applying it in a vacuum would be a real obstacle.

Throw water balloons.

Skins that will explode on impact filled with the reflective goop of your choice. Shoot them in the general direction.

Paint powder: carbon black on one pole, white chalk dust on the other.

If it's ice rather than rock, dispersing carbon black over the surface would cause the sun-facing side to heat up and out-gas faster than it otherwise would, which might be enough to push it off-course.

These things are usually rotating. There's no specific sunward-facing surface.

Dave Bell@62: that reminds me of the odd fact which I learned from stumbling on this PDF (that I certainly don't fully understand) many years ago: the chaotic tumbling of Saturn's moon Hyperion means that quantum mechanics is something you need to worry about when modelling it. Sounds ridiculously unlikely when talking about a rock the size of NYC, but there you go. The chaos of Hyperion's dynamics comes from complicated interactions with Saturn and its other satellites so presumably an isolated meteor on an orbit that intersects Earth's wouldn't behave like this. And even if it did, we probably couldn't utilise QM to dodge it by hiding under the bed and refusing to observe it, which would be my brilliant plan.

If we never get the FTL drive that we want, the Solar System is packed full of enough weird stuff to entertain us.

Dave Bell: that's why I suggested coating the whole thing, instead of just one side. If it's rotating slowly enough, the sunny side will be outgassing the most, and so it will be slowed in its path sunward, hopefully enough to miss us.

If it's rotating too fast, or if it's insufficiently volatile, we'd need a different tactic.

Steve with a book @ #63, it is probably indicative of some deep-seated psychological or neurological issue on my part that I now have "Iphigenia in Brooklyn" running through my head. ("As Hyperion across the sky his flaming chariot did ride, Iphigenia herself in Brooklyn found.")

Lila@65: heh, thanks for mentioning that piece; I'd never heard it before.

I had a period of sedulous self-improvement several years ago when I kept tuning into BBC Radio 3. At least half the time I'd find myself in the middle of one of those Handel oratorios that consist of random harpsichord trills and chords alternating with minor Old Testament characters advancing the story by singing very repetitively. This brought back the memories.

Lila @65, alas, all my PDQ Bach is on vinyl, and I no longer have a functional record player.

How massive can an object be before we just couldnt deflect it in practice? I mean, if you have something the mass of the Earth headed for us, it's hard to imagine that we could do much about it, but maybe this is my failure to think on the right scale. (When the mass gets close to that of Earth, my intuition is that it starts making sense to try to change the motion of the Earth to avoid it, but it's hard for me to imagine us managing that.)

albatross @68: Mass in itself is not a problem: a very small change over a long period of time would be effective at causing a miss (this is what makes solar sails possible). The primary gravity source affecting the approaching planetoid is goin to be the sun for much longer than the earth; changing the planetoid's velocity vector even by an infinitesimal amount (continuously, or even only one time) at several years out will make it miss by a huge distance. The earth's gravity doesn't act as an effective tractor beam on the object until it's very close, in astronomical terms.

As the planetoid gets closer, the amount of energy put into deflecting it will have to go up. At some point, it becomes effectively impossible. But it's not simply a function of mass. It's much more like the problem of finding a specific port while sailing across the ocean than it is like trying to find a continent.

Back when Shoemaker Levy 9 was about to hit Jupiter, Bill Nye did a size comparison illustration. Standing beside a four-foot picture of Jupiter, he puffed some talcum in the air. He claimed those were in the right size ratio.
The objects we need to be able to divert are from Tunguska size to dinosaur -killers. If you want an engineering back of the envelope number, up to 1 km. If I recall, those come along around every 80K years or so in collision orbits.
We're really talking about two fast objects not on head-on courses. Very small differences are going to count. Consider the Russian event, at 5km/s or so, and 50 km altitude. Nudge it twenty-four hours before by 1 m /s at least an 86,400 meter change in the geometry. An extra 86 km in height would be a clean miss. Best to get the vector right, though!
I'm too lazy to dig up the calculus and do it right, but I'd expect there's a reasonable fit between size and warning time, and therefore fairly constant sizes of intervention up to the point of no return.
There aren't lots of very big (moon-sized) rocks to worry about. Apophis, at 325m is the kind of thing we need to handle. Tunguska might have been a third of that size.

About a month after a meteor hit the Russian city of Chelyabinsk, a U.S. House panel led by Texas’ Rep. Lamar Smith, put scientists on the hot seat, asking if the United States is prepared for such an event.

NASA administrator Charles Bolden was widely reported to have told them that if an asteroid is headed to Earth, his advice is to “pray.” He did say that, but as is often the case, it’s not the whole story.

“The funding did not come,” Bolden said. “And so the answer to you is, if it’s coming in three weeks, uh, pray.”

http://blog.sfgate.com/hottopics/2013/03/21/why-nasa-chief-said-prayer-is-the-way-to-go-with-an-asteroid/