Russian meteorite strike

[90019]

I'm surprised no one has posted anything about this yet.

Meteor strike injures hundreds in central Russia

A meteor crashing in Russia's Ural mountains has injured at least 950 people, as the shockwave blew out windows and rocked buildings.

Most of those hurt, in the Chelyabinsk region where the meteor fell, suffered cuts and bruises but at least 46 remain in hospital.

A fireball streaked through the clear morning sky, followed by loud bangs.

President Vladimir Putin said he thanked God no big fragments had fallen in populated areas.

A large meteor fragment landed in a lake near Chebarkul, a town in Chelyabinsk region.

The meteor's dramatic passing was witnessed in Yekaterinburg, 200km (125 miles) to the north, and in Kazakhstan, to the south.

"It was quite extraordinary," Chelyabinsk resident Polina Zolotarevskaya told BBC News. "We saw a very bright light and then there was a kind of a track, white and yellow in the sky."

"The explosion was so strong that some windows in our building and in the buildings that are across the road and in the city in general, the windows broke."

Officials say a large meteor partially burned up in the lower atmosphere, resulting in fragments falling earthwards.

Thousands of rescue workers have been dispatched to the area to provide help to the injured, the emergencies ministry said.

The Chelyabinsk region, about 1,500km (930 miles) east of Moscow, is home to many factories, a nuclear power plant and the Mayak atomic waste storage and treatment centre.

From Russia Today:

[youtube]90Omh7_I8vI[/youtube]


I suppose one of the positives of it occuring in Russia is that so many people have dashcams in their cars (they get cheaper insurance if they do, iirc), so we get so much footage of things like this happening, which we wouldn't otherwise have if it happened elsewhere - we would have got loads of videos people had taken on cameras and phones once they'd got them out, or from CCTV cameras pointing the other way, but we wouldn't be so likely to catch the beginning of the event occuring.
It's like the plane crash that happened in Russia in December, where the plane overshot the runway and crashed into a highway - being Russia at least one of the cars had a dashcam, and on the very same day it was uploaded to Youtube.
It must also be mentioned about the part that video sharing sites like Youtube play - this meteorite strike only happened this morning, and it wasn't long before the videos started appearing.

 

[JamesRowden]

It is a meteorite, not a meteor (because it hit the Earth's surface and did not get completely burnt up in the atmosphere).

Perhaps the BBC writers should be sent back to school to revise key stage 3 science.

 

[SS4]

Looks like Sturm got his (S)COP

I wonder if was as spectacular as the one over Canada a few years back (sadly no flash for me so I can't watch it )

 

[Johnuk123]

When you've seen one meteorite you've seen them all.

 

[christopher]

Experts examining the remains of the meteor have confirmed they have found traces of Horse DNA.

 

[generalvegitable]

Experts examining the remains of the meteor have confirmed they have found traces of Horse DNA.

Since when did Tesco have branches in space?

 

[tsr]

"Please stand well away from the edge of the inner atmosphere. The approaching meteor is not scheduled to stop here."

Then...

"Correction: The meteor now approaching our planet will terminate short of its destination. This is due to a trajectory which could not be rectified."

A few minutes later...

"This meteorite will divide here. Parts 1 to 18 will continue to Russia. Parts 19 to 44 will continue to Kazakhstan."

 

[michael769]

We are sorry to annouce that the 11:15 to 61 Cygnus will now terminate at the solar system. This is due to a planet on the trajectory. We apologise for any inconvenience caused,.

 

[Masboroughlad]

It will be something like this (but loads bigger) that eventually will end the world. He wrote cheerfully.....

 

[melena]

Well, they say it only weighed about 10 tons, so the one that flew by this evening weighing 130,000 tons would probably make a large dent in the planet population as well as a large hole in the planet.

 

[jon0844]

Can't believe the full size meteor didn't stop here. I'd just bought a £10 first class advance to hell.

 

[Manchester77]

It will be something like this (but loads bigger) that eventually will end the world. He wrote cheerfully.....

Well, they say it only weighed about 10 tons, so the one that flew by this evening weighing 130,000 tons would probably make a large dent in the planet population as well as a large hole in the planet.

Isn't this a cheery thread :roll:

 

[Xenophon PCDGS]

Was this event predicted in the Mayan Long-Count Calendar ?.....or even in Old Moore's Almanac ?....:roll:

Remind myself tomorrow to look up the book of predictions by Nostrodamus...
--- old post above --- --- new post below ---

Since when did Tesco have branches in space?

Do you not realise that these are already in existance, but with the "cloaking device" switched on, and I am sure that they will already have their usual "retrospective" planning applications in and will be as ready as usual to overcome all the expected protests from the the little woollen knitted cute mice from Clangers, Klingons, Romulans, Daleks, Ewoks, etc....

"It's shopping, Jim, but not as we know it"......:roll:

 

[Trog]

Is it just me that thinks that the hole in the ice where the fragment of meteorite is supposed to have hit the frozen lake shown on the BBC news web site is suspiciously round?

I would have expected a much rougher hole, and one that suggested an impact with a strong sideways component.

 

[LE Greys]

Is it just me that thinks that the hole in the ice where the fragment of meteorite is supposed to have hit the frozen lake shown on the BBC news web site is suspiciously round?

I would have expected a much rougher hole, and one that suggested an impact with a strong sideways component.

Remember it's still doing an enormously high velocity, and gravity would pull it to a roughly-vertical trajectory. An unexploded shell would leave a similarly round hole from a high-velocity impact.

Although, from its behaviour, it actually sounds more like the impact of a small comet than a meteorite. Something that would be big, but not very dense, being mostly a big block of ice. I originally thought it was a companion of the big one that passed by, an asteroid moon, but it seems to have been unrelated.
--- old post above --- --- new post below ---

Well, they say it only weighed about 10 tons, so the one that flew by this evening weighing 130,000 tons would probably make a large dent in the planet population as well as a large hole in the planet.

They seem to be attracted to Russia as well (being the biggest country in the world might affect this). Assuming this one is a similar size to the Tunguska impactor, it would be the equivalent of at 5-30 megaton nuclear bomb going off.

 

[Trog]

I still think it is suspiciously round, it looks like someone scribed out a circle and cut it out with a saw. Even if a high speed impact cut a clean hole, I would have thought the shock wave from the meterorite going into the water below would have thrown back the edges of the hole.

 

[michael769]

Most meteorite strikes leave almost perfectly round craters, as can be seen on the moon and other objects in the solar system.

The hole is not the result of the metorite strike itself, but arises from the energy released by the impact. The energy released from the impact is absorbed into the ground but is so intense that the ground liquifies and then explodes outwards. The energy released by the explosion acts in all directions evenly and as the ground has turned to a liquid there is nothing to distort the shockwave causing the characteristic circular crater. all traces of the original (and not round) hole created by the hit is destroyed in the explosion.

http://www.scientificamerican.com/article.cfm?id=why-are-impact-craters-al

Incidentally raindrops also always create circular ripples even when they hit at an angle.

You can very rarely get a non circular hole, that happens where the meteorite stikes at such an acute angle that it skips over the surface like a stone skipping on water, in which case the explosion does not occur in the ground (but in the air) allowing the impact scar(s) to persist.

NASA are estimating that the meteor was 17m in diameter and weighed 10,000 tonnes. The fireball was brighter than the sun and released 500 kilotonnes, so similar to a very large intercontinental neuclar weapon (trident missles are 100kt).

 

[Peter Mugridge]

The vast majority of the damage was caused by the sonic effects, not from the object itself. One of the video clips clearly shows it detonating in mid air ( that's the bit where it gets very bright suddenly and then a dimmer streak continues forwards ).

Tunguska... I think this one was probably smaller than the Tunguska object; that one supposedly detonated 3 - 4 miles up and still flattened 80 million or so trees. I suspect a blast of that intensity yesterday would have done rather more damage than the video clips indicated.

 

[LE Greys]

The vast majority of the damage was caused by the sonic effects, not from the object itself. One of the video clips clearly shows it detonating in mid air ( that's the bit where it gets very bright suddenly and then a dimmer streak continues forwards ).

Tunguska... I think this one was probably smaller than the Tunguska object; that one supposedly detonated 3 - 4 miles up and still flattened 80 million or so trees. I suspect a blast of that intensity yesterday would have done rather more damage than the video clips indicated.

I was thinking that if 2012 DA14 (the one that missed) had actually hit us, that would be similar to Tunguska. From the sounds of things, they were of similar sizes. I tried looking for it last night, but couldn't see a thing.

 

[Peter Mugridge]

You would not have seen it unless you had a good pair of binoculars at the very least ( depending on sky quality ) as it was below naked eye visibility.

I agree, a strike by an object the size of 2012 DA14 would have.... err... had interesting consequences.

 

[Xenophon PCDGS]

I agree, a strike by an object the size of 2012 DA14 would have.... err... had interesting consequences.

Noting the stated mass of both recent objects that visited the orbit of the Earth this week, whilst the smaller one over Russia was said to have exploded at some height over the ground area, what would have occurred in the case of an object of the stated size of 2012 DA14 ? Would have it have been a similar explosion in the atmosphere or a ground strike....or a combination of both ?

 

[LE Greys]

You would not have seen it unless you had a good pair of binoculars at the very least ( depending on sky quality ) as it was below naked eye visibility.

I agree, a strike by an object the size of 2012 DA14 would have.... err... had interesting consequences.

The enormous light in the High Street don't help much, you're lucky if you can make out Sirius some nights.

Noting the stated mass of both recent objects that visited the orbit of the Earth this week, whilst the smaller one over Russia was said to have exploded at some height over the ground area, what would have occurred in the case of an object of the stated size of 2012 DA14 ? Would have it have been a similar explosion in the atmosphere or a ground strike....or a combination of both ?

It probably depends on the composition of the impactor. Some asteriods are solid, others are 'rubble piles' loosly held together by gravity. There are also various types, metallic once (M-Type) containing mostly iron and nickel, stony ones (S-Type) containing siliacte rocks and carbonaceous ones (C-Type) with lots of additional carbon. Others can be intermediate between the different types. So it depends on what variety actually hit and how much atmosphere it passed through on the way down. Drop a cannonball into an atmosphere to simulate an M-Type, and it would melt on the way down. Drop a rock of similar mass to simulate an S-Type, and it would conduct heat much more slowly. Wikipedia has 2012 DA14 as an L-Type, which is very similar to an S-Type, making it brittle, but quite heat-tolerant. Please correct me if I'm wrong, but I suspect that would airburst like the Tunguska one (the Meteor Crater one, which impacted, was supposedly an M-Type). The Wiki entry agrees with this.

It is estimated that, if it were ever to impact Earth, it would enter the atmosphere at a speed of 12.7 km/s, would have a kinetic energy equivalent to 3.5 megatons of TNT, and would produce an air burst with the equivalent of 2.9 megatons of TNT at an altitude of roughly 8.5 kilometers (28,000 ft). The Tunguska event has been estimated at 3–20 megatons. Asteroids of approximately 50 meters in diameter are expected to impact Earth once every 1200 years or so. Asteroids larger than 35 meters across can pose a threat to a town or city.

Although it would have produced one tenth of the energy, one would have expected scenes like this on the ground rather than a crater (please bear in mind this is 19 years after the impact).

 

[michael769]

Please correct me if I'm wrong, but I suspect that would airburst like the Tunguska one (the Meteor Crater one, which impacted, was supposedly an M-Type). The Wiki entry agrees with this.

My view is that it would not have been big enough to reach the ground intact (regardless of composition). But at 2.9 megatonnes, if the resultant air blast occurred over London everything inside the M25 would be destroyed.

 

[tsr]

But at 2.9 megatonnes, if the resultant air blast occurred over London everything inside the M25 would be destroyed.

It is a sobering thought, certainly. Without sounding silly, I wonder if there IS any way to employ any of our current space/upper atmosphere exploration technologies in order to respond to such a threat. I don't know if the cost would be worthwhile, which I think is the single biggest problem.

On a more flippant note... in such an event, I am sure Chiltern Railways would still continue to run into London Marylebone...

 

[LE Greys]

It is a sobering thought, certainly. Without sounding silly, I wonder if there IS any way to employ any of our current space/upper atmosphere exploration technologies in order to respond to such a threat. I don't know if the cost would be worthwhile, which I think is the single biggest problem.

On a more flippant note... in such an event, I am sure Chiltern Railways would still continue to run into London Marylebone...

It's possible, provided it's done far enough away. The Earth orbits at over 98,000 fps, so the 'window' to hit the Earth is 214 seconds long if the object was crossing the Earth's orbit at right angles. Gravity probably doubles that, and I don't know what effect crossing at an oblique angle would have. A change of 10 fps in any direction a year before impact would be more than sufficient to miss the Earth (I think). A big enough explosion (say a nuclear bomb) or a large kinetic impact could do this in one go, attaching a rocket or a solar sail could do it over a longer time. Even painting the thing white would change its course. The main thing needed, though, is constant observation. The sooner an object is detected, the sooner its trajectory can be plotted, therefore the sooner the mission can be launched. If you have more time, you need a smaller deflection, and there's always time to plan a second mission if the first fails.

 

[Peter Mugridge]

The option of exploding a nuclear bomb to achieve the "nudge" is unlikely to be employed because of the risk of disrupting a single large object into hundreds of smaller objects all still heading for us; gentle nudges are the favoured solution now.

 

[LE Greys]

Just found this rather interesting page in ICL's website.

http://impact.ese.ic.ac.uk/

 

[43021HST]

A curious but grim thought, thank god this didn't happen 30 years ago, during the cold war.