Author Topic: Meteor Strikes Chelyabinsk, Russia  (Read 136452 times)

Offline hektor

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #220 on: 02/16/2013 11:11 AM »
I guess it will be an interesting case study in the future. Explosion of 500 kt at altitude 30 km above a large city.

Offline psloss

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #221 on: 02/16/2013 11:24 AM »
Let the hearings begin!

http://thehill.com/blogs/blog-briefing-room/news/283427-house-committee-to-hold-hearing-on-asteroids-that-pose-a-potential-threat-to-earth

Ah! More funding for SLS! And hopefully an agency wide raise.

Good.
No, the hearing is just public discovery/disclosure (and the other things that come with hearings).  It might extend the visibility of the event, but increased federal funding is far from a certainty, especially on a large scale.

Offline smoliarm

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #222 on: 02/16/2013 11:27 AM »
... looking at the collection of seismograms...
Is there any chance to tell from heliplot if we are looking at shock wave hitting the ground or at impact of massive solid body? (Theoretically, there should be difference in shape/magnitude, but I have no personal experience here).
Or, in other words - could you tell by heliplot data that there was a large (on a tonne scale) body hitting the ground with supersonic speed? Or, do these plots give evidence that there was NO such event?

Offline R7

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #223 on: 02/16/2013 11:45 AM »
I guess it will be an interesting case study in the future. Explosion of 500 kt at altitude 30 km above a large city.

Even if yields are the same effects of nuke would be quite different, no? Meteor dissipates it's energy during several seconds to path of several tens(?) of kilometers. Nuke releases it all in microseconds to one point. Wildly different shockwave ensues.
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Offline yg1968

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #224 on: 02/16/2013 12:23 PM »
There's also never (during the space age) been such a pertinent, documented case of why it is important, and probably has never been such public attention to the topic, either.

Gazing into the crystal ball, I can see Congress throwing some more money at the search effort. When we did our NEO study a few years ago the committee generally believed that the amount of money spent on doing the surveys should be increased a bit. Because NASA was then spending $4.5 million on the subject, "a bit" could be increasing it to $10 million annually.

But here's some of the issues:

-in order to substantially improve the surveys for these objects you have to spend A LOT more money. Essentially, you have to build a space-based telescope. No matter what B612 says, that's a half billion dollar investment.

-compare the costs, and the risks, to other events that kill lots of people. If you go back only one decade I bet that you can easily determine that over 800,000 people worldwide were killed by seismic events (250,000 in Haiti alone). Earthquakes represent real dangers to human life.

-where should that $500+ million be spent for maximum effect? Should it be spent on things like asteroids, which are very rare, or should it be spent on things that are much more common?

But I'd hate to see a knee-jerk political reaction to throw cash at this without carefully balancing the issues.

If the cost is $500M, it would seem reasonable considering that NASA has a $17B per year budget. This is the kind of work that NASA is expected to do. If NASA doesn't do this kind of work, taxpayers will eventually question whether their $17B per year "investment" into NASA is put to good use.

Offline ChileVerde

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #225 on: 02/16/2013 01:35 PM »
... looking at the collection of seismograms...
Is there any chance to tell from heliplot if we are looking at shock wave hitting the ground or at impact of massive solid body? (Theoretically, there should be difference in shape/magnitude, but I have no personal experience here).

Or, in other words - could you tell by heliplot data that there was a large (on a tonne scale) body hitting the ground with supersonic speed? Or, do these plots give evidence that there was NO such event?

I would think so, but don't really know either. Hopefully people who have expertise in such matters will publish on the event in due course.
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Offline FinalFrontier

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #226 on: 02/16/2013 01:52 PM »
Let the hearings begin!

http://thehill.com/blogs/blog-briefing-room/news/283427-house-committee-to-hold-hearing-on-asteroids-that-pose-a-potential-threat-to-earth

Ah! More funding for SLS! And hopefully an agency wide raise.

Good.
No, the hearing is just public discovery/disclosure (and the other things that come with hearings).  It might extend the visibility of the event, but increased federal funding is far from a certainty, especially on a large scale.


I meant metaphorically of course.
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Offline Blackstar

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #227 on: 02/16/2013 01:58 PM »
If the cost is $500M, it would seem reasonable considering that NASA has a $17B per year budget. This is the kind of work that NASA is expected to do. If NASA doesn't do this kind of work, taxpayers will eventually question whether their $17B per year "investment" into NASA is put to good use.

Here is what has happened in the past:

A few members of Congress (Rohrabacher is one) have inserted language into NASA authorization bills (not appropriations bills) requiring the agency to detect potentially hazardous NEOs. Because of the way that Congress works, where the leadership often has to give out trinkets to the members in order to get things passed, this language has survived into authorization acts even though the vast majority of members don't care about the subject or even know anything about it. (Note: this happens all the time for lots and lots of things, not just searching for asteroids.)

This requirement landed on NASA, but did not come with any new money appropriated for that purpose. Now what the authorizing committee hoped would happen is that the administration (White House/President) would submit a budget proposal that included sufficient money to accomplish the task. But the administrations (Clinton, then Bush, then Obama) didn't care about the issue. So they did not ask for additional money to do it, they simply redirected money from inside NASA to do it partway. The result is that the money has gotten cut out of other things at NASA, and the agency has never really had the resources to accomplish it.

This is just a variation of the common situation of the "unfunded mandate."

What people within NASA have worried about for years is that Congress would increase the unfunded mandate, essentially directing that more of the agency's current budget be allocated for doing this thing. That would force them to cut the money from something else. But what? It's common for the advocates to say "take it from the science budget because asteroids are science." But counting rocks is not a scientific pursuit. And this is a terrestrial defense project, so why should that money come out of the science budget? Shouldn't the Department of Homeland Security or the DoD pay for it? And officially the administration has set a goal of sending humans to an asteroid, and so shouldn't the human spaceflight program spend the money searching for asteroids?
« Last Edit: 02/16/2013 01:58 PM by Blackstar »

Offline mlindner

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #228 on: 02/16/2013 02:22 PM »
Anyone who knows russian. What are they saying in this video with regards to the impact crater?

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Offline RichardAKJ

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #229 on: 02/16/2013 02:41 PM »
If the cost is $500M, it would seem reasonable considering that NASA has a $17B per year budget. This is the kind of work that NASA is expected to do. If NASA doesn't do this kind of work, taxpayers will eventually question whether their $17B per year "investment" into NASA is put to good use.

Here is what has happened in the past:

A few members of Congress (Rohrabacher is one) have inserted language into NASA authorization bills (not appropriations bills) requiring the agency to detect potentially hazardous NEOs. Because of the way that Congress works, where the leadership often has to give out trinkets to the members in order to get things passed, this language has survived into authorization acts even though the vast majority of members don't care about the subject or even know anything about it. (Note: this happens all the time for lots and lots of things, not just searching for asteroids.)

This requirement landed on NASA, but did not come with any new money appropriated for that purpose. Now what the authorizing committee hoped would happen is that the administration (White House/President) would submit a budget proposal that included sufficient money to accomplish the task. But the administrations (Clinton, then Bush, then Obama) didn't care about the issue. So they did not ask for additional money to do it, they simply redirected money from inside NASA to do it partway. The result is that the money has gotten cut out of other things at NASA, and the agency has never really had the resources to accomplish it.

This is just a variation of the common situation of the "unfunded mandate."

What people within NASA have worried about for years is that Congress would increase the unfunded mandate, essentially directing that more of the agency's current budget be allocated for doing this thing. That would force them to cut the money from something else. But what? It's common for the advocates to say "take it from the science budget because asteroids are science." But counting rocks is not a scientific pursuit. And this is a terrestrial defense project, so why should that money come out of the science budget? Shouldn't the Department of Homeland Security or the DoD pay for it? And officially the administration has set a goal of sending humans to an asteroid, and so shouldn't the human spaceflight program spend the money searching for asteroids?

In your opinion, is this likely to change given the close pass and Russian impact?

Online Archibald

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #230 on: 02/16/2013 03:01 PM »
I think we'd need more data to increase confidence that the rocks came from the same meteor source.

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Offline psloss

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #231 on: 02/16/2013 03:08 PM »
If the cost is $500M, it would seem reasonable considering that NASA has a $17B per year budget. This is the kind of work that NASA is expected to do. If NASA doesn't do this kind of work, taxpayers will eventually question whether their $17B per year "investment" into NASA is put to good use.
Those kinds of things -- examining and questioning U.S. federal space policy -- happen in small circles like this forum; most taxpayers don't spend more than a few web clicks worth of time on space policy.

If this event had been local to the U.S., I would agree with others here speculating possible motivation to act; however, as it relates to the U.S., this is more along the lines of the Indian Ocean tsunami back at the very end of 2004.  (Or the Haitian earthquake already mentioned.)

Offline Artyom.

Re: Meteor Strikes Chelyabinsk, Russia
« Reply #232 on: 02/16/2013 03:09 PM »
Anyone who knows russian. What are they saying in this video with regards to the impact crater?



Sorry if I'm not clear translated  ::), but nothing new... It supposedly fell one out of the wreckage. Crater from a meteorite collision with Earth is at least 10 meters. Police officers yet don't give official comments. According to regional GUVD (City Police Department) there it is collected examples of black, strong substance which are sent for examination. Background radiation is normal :) !
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Offline JohnFornaro

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #233 on: 02/16/2013 03:19 PM »
-compare the costs, and the risks, to other events that kill lots of people. ... Earthquakes represent real dangers to human life.

-where should that $500+ million be spent for maximum effect? Should it be spent on things like asteroids, which are very rare, or should it be spent on things that are much more common?

Well, yes, but the question of what 0.5 $G buys in either case arises.

I.e., suppose that amount of money buys a pretty complete assessment of asteroid risk that can be followed up with more $$ on prevention/ mitigation.

You then have to figure out how the same amount of money can be spent on earthquake risk assessment and prevention/mitigation.

In the case of earthquakes, we probably aren't going to prevent them any time soon, so does the 0.5 $G go into earthquake resistant construction in Haiti, Iran and other quaky places? And how much of the population gets protected for that amount of money?

First, you have no grounds to make the supposition that $500M "buys a pretty complete assessment of asteroid risk".

In addition, since neither large quakes nor large asteroid strikes can be prevented, the other factor that could be "bought" would be prediction.

With respect to a quake in a coastal area, several days of prediction could result in an orderly evacuation, with no real ensuing panic.

In the case of an asteroid, one would have to predict the city which would be hit.  Hard to imagine that evacuation taking place without panic.  Hence, hard to imagine the city being predicted publicly by name.  If the prediction were six months in advance, hard to imagine an evacuation, tho the panic might be reduced.

So I think part of what RobotBeat suggests is spot on:

And yet, we don't do it [space programs in general] JUST because of an actuarial cost-benefit analysis. Very little of what NASA does would qualify, maybe some of the stuff in aeronautics.

And again, there is an existential aspect of it that isn't captured in an actuarial perspective and it's one that doesn't really apply to earthquake prediction, etc.

How much have we spent on Hubble? And Hubble doesn't really have an existential purpose. Half a billion for studying NEOs (and other targets, for sure) isn't unreasonable. Which isn't to say we /shouldn't/ be studying how to predict earthquakes, etc. Your arguments seem to work just as well against any kind of space project.

His is a less confrontational way of saying that fundamentally, mankind doesn't have an "actuarial" need for space programs such as Hubble.  The ability to predict an asteroid strike would have an actuarial value, but it would certainly have to be compared against competing needs with higher value and better chances of accurate prediction.

An economist would say you equate marginal-utility-to-price ratios over all your purchases. A non-economist would say you maximize the bang for your bucks.

Governmental spending should be allocated similarly and probably is.

What's the weather like on your planet?

... Snarky comments aside, our government works quite nicely on the whole. As evidence I’ll cite that one of our greatest problems is the number of people who want to come here, greatly in excess of what our immigration laws allow.

Thing is, QG's right in snarking your naive economist.  "Marginal utility to price ratios" might apply in big business to some extent, but not really to ordinary Janes.  A trip to the refrigerator upstairs illustrates the point:

There is no economic theory which can even begin to model the economic difference between "ChaChing Cherry", "Art Dealer Teal-er", "Mango Mango 400", "260 Sonic Boom", "B426 Trevi Gold F", or any of the three dozen economic products on that refrigerator shelf.  And these are only the tiniest subset of the economic decisions out there to be made in the private sector.

Worse, while our government might be the best on the planet, it doesn't work "quite nicely on the whole", particularly when assesing "marginal utility to price ratios".
Sometimes I just flat out don't get it.

Offline Ben the Space Brit

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #234 on: 02/16/2013 03:23 PM »
From the data I've seen, the Chelyabinsk Object was in a high-inclination Earth-grazing orbit.  Additionally, as it's trajectory seems to have been from the direction of the Sun, it might have also been in a high-eccentricity orbit.  In other words, it might have normally been closer to the Sun than the Earth and either off the ecliptic or optically close to the Sun in the sky.  I think that would have worked strongly against it being detected before.
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Online sanman

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #235 on: 02/16/2013 03:53 PM »
What if this thing had not been in an Earth-grazing trajectory, but had instead hit full-on, in surface-normal trajectory? Would it have smashed into the ground rather than exploding overhead?

Offline Mongo62

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #236 on: 02/16/2013 04:00 PM »
From the science blog Dynamics of Cats:

Quote
Air has density of about 10^-3, at ground level decreasing approximately exponentially with scale height, and the scale height is of order 10 km. Therefore meteors tend to break up at 10-20 km altitude if they don’t make it to the ground. A 1 m rock needs to sweep a path of over 2 km through the air to stop effectively, a 12 m rock needs about 24 km of air to stop. So a rock that big coming straight down will likely hit the ground.

The Chelyabinsk meteor came in at a shallow angle, and so traversed a column of air long enough to brake it and break it. This is very fortunate, or we’d have had a ground detonation of a few hundred kilotons and likely mass casualties.

Most of the injuries seem to have been from broken glass, consistent with reports of other large explosions.

Glass breaks from overpressure of about 1/4 PSI – and as the bomb damage calculator (below) shows, that overpressure goes out to about 20 km radius (for ground detonations which this was not). Here we had an air detonation (worse) but with the energy spread out over a linear track, not deposited instantaneously at a point (both better and worse).

Hence the damage was consistent along the track and for tens of km either side of it, but nowhere was there a point or line of extreme destruction. A little bit higher energy impact, steeper impact angle, faster speed or bigger rock, and there would have been a zone of severe damage surrounded by an elongated annulus of the moderate damage actually seen, and there would have been many deaths.

Offline R7

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #237 on: 02/16/2013 04:01 PM »
What if this thing had not been in an Earth-grazing trajectory, but had instead hit full-on, in surface-normal trajectory? Would it have smashed into the ground rather than exploding overhead?

See

http://forum.nasaspaceflight.com/index.php?topic=31118.msg1013385#msg1013385
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Online Archibald

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #238 on: 02/16/2013 04:39 PM »
Incidentally the reason why a lot of Russian news report insists heavily on "low radiation levels",   is because that unfortunate region also suffered some huge nuclear disaster back in 1957.
http://en.wikipedia.org/wiki/Kyshtym_disaster

Offline LegendCJS

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Re: Meteor Strikes Chelyabinsk, Russia
« Reply #239 on: 02/16/2013 05:31 PM »
There's also never (during the space age) been such a pertinent, documented case of why it is important, and probably has never been such public attention to the topic, either.

Gazing into the crystal ball, I can see Congress throwing some more money at the search effort. When we did our NEO study a few years ago the committee generally believed that the amount of money spent on doing the surveys should be increased a bit. Because NASA was then spending $4.5 million on the subject, "a bit" could be increasing it to $10 million annually.

But here's some of the issues:

-in order to substantially improve the surveys for these objects you have to spend A LOT more money. Essentially, you have to build a space-based telescope. No matter what B612 says, that's a half billion dollar investment.

-compare the costs, and the risks, to other events that kill lots of people. If you go back only one decade I bet that you can easily determine that over 800,000 people worldwide were killed by seismic events (250,000 in Haiti alone). Earthquakes represent real dangers to human life.

-where should that $500+ million be spent for maximum effect? Should it be spent on things like asteroids, which are very rare, or should it be spent on things that are much more common?

But I'd hate to see a knee-jerk political reaction to throw cash at this without carefully balancing the issues.

There is an exciting body of evidence showing that large earthquakes are preceded by magnetic disturbances due to large underground current flow form piezo electric effects.  Studies have spotted these signatures by their effect on GPS signals.  I can imagine that a large pot of money could be used to make a monitoring system that would provide warning to regions showing similar signatures.  Smaller earthquakes, which are harder to detect, do not cause as much damage (unless you have crap enforcement of construction standards).

The actions to take in response to a warning would be pre-positioning emergency goods, prep-work like reinforcements, window coverings (kind of like hurricane), clearing of evacuation routes and fire hazards, removing stuff form precarious high shelves... up to possible evacuations.

There have been periods of recent history when the Chelyabinsk even would have sparked WWIII, and there are some locations on this planet where it might have sparked regional conflicts even today.

Both spending for better NEO detection and spending for Earthquake detection is spending on research, I don't see the problem with it, even if it is knee-jerk based decisions that make it happen.
Remember: if we want this whole space thing to work out we have to optimize for cost!

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