Living in the country, there are lots of long boring drives where you mind wanders and you grow up very familiar with what a "shooting star" looks like streaking against the night sky.
One day, driving home I happened to look out at something I thought was a plane and nearly drove off the road as I saw a meteroid falling silently through the sky. There was absolutely no sound and it moved much slower than I expected. After I regained control of my car and pulled it over to get out and watch, I saw small pieces silently broke away and the light show continued until it went over the horizon. It was totally unlike anything I'd ever seen before or since. It's dreamlike and beautiful.
I waited a few minutes after it went below the horizon since the angle it went on made me think it might have made it to the ground, but I never heard anything. It was never in the news, and nobody talked about it afterwards, for all I know I'm the only one who ever saw it. It was both terrifying and amazing. I had no idea what I was looking at since it didn't look like any picture of this phenomenon I'd ever seen.
One thing I'm sure of, is that I've never seen a video that ever does such a spectacle justice. There's so many subtle details that get completely obliterated on video.
Here's some video that do a pretty good job of showing what they look like.
The videos of the one in Russia are on an entirely different scale. The sonic boom was tremendous, the amount of light being thrown off of that thing was unbelievable. Extrapolating from what I saw and how I now know video changes things, this must have been an unbelievable beautiful and terrifying sight.
Wow, those videos (and your story) are mindblowing.
I wonder what must have gone through the minds of our ancestors when, hundreds or thousands of years ago, they'd witness such events (let alone ones similar to the Russian meteor). A lot of old creation myths etc. make a lot more sense now :)
Nice coverage. I especially like the infrasound analysis. The estimate of 100kT explosion suggests this thing was an order of magnitude scarier in person than it was on video, and it was pretty damn scary on video.
Yes, its the same scale, but explosions in atmosphere distribute their energy over the surface of a sphere. Surface goes up with the square of the radius (hence the inverse square law in so many things). Here being far enough away helps, the over-pressure broke non-tempered glass of the buildings closest but not the tempered glass of the vehicles.
I've watched three shuttle re-entries (benefit of being in California when they were landing in Florida) when the shuttle entered a dense enough atmosphere to create a contrail it looked very similar to this one (although it had a glowing purple leading edge which I never did get a satisfactory explanation for).
I've tried to imagine what this sort of event would look like to someone driving, now I know. Personally I would be expecting the shock wave so I would try to find some place to pull off an avoid being directly impacted by it. I did some experiments with hydrogen and oxygen in a misspent youth (its a pretty powerful explosive at the correct mixture) and the shock wave can take your breath away.
Yes, however both of those bombs were specifically targeted, and were detonated at 2000' (Hiroshima) and 1500' (Nagasaki) above ground level, vs. 20-30 miles (105,000' - 158,000') above ground for the Chelyabinsk meteor.
Blast effects trail off markedly with distance. For Hiroshima, most blast damage was confined to a radius of 1.6 km from ground zero, roughly correlating to an overpressure of 5 psi. Glass will fragment at much lower pressures, generally 0.14 - 1.4 psi. Blast damage falls as the inverse cube of distance.
The difference between mother nature and a human adversary is that Mom has zero fucks to give for where she does her work. Asteroid impacts are randomly distributed around the planet, for the most part (latitude may play some role). Most impacts should occur over oceans. Russia, being the largest country, and Siberia, being the largest region of Russia, will tend to see more impacts than other areas, though on an area-normalized basis the maths should work out. So while we may see larger energy releases from space impacts, they'll typically be targeted away from populated regions. Not that a large enough impact couldn't still make for a really bad day.
This is actually completely useless since these explosions are far closer to the earth -- probably between 100 meters and 1 km altitude [1], vs. 10-30 km estimates for this meteor. Also, it only shows thermal radiation effects, which are insignificant here.
This is an appropriate calculator for meteors [2-3], including the effects of the actual blast (overpressure), not just heat. The documentation says windows are shattered at about 6,900 Pa (1 psi).
Density:
A meteor's energy release could be described as a long narrow cone. An atom bomb would in a dense sphere/hemisphere. To make it comparable you'd have to get the meteor to expend all it's kinetic energy in one spot (due to interaction with the atmosphere this is unlikely). The shockwaves are spread out over a larger total distance. I.E. Less concentrated.
Time:
A nuclear weapon releases all it's energy in milliseconds into a single pressure wave. A meteor tends to shred itself slowly in the atmosphere (relative to a nuke). Time is immensely important when measuring the destructive force. Slowing a car from 50mph to 0mph is the same 'total energy' if you do it in 10seconds or .1 seconds, but the car will suffer significantly more in the .1 second scenario.
My impression of the Chelyabinsk meteor was that it fragmented significantly about 14-15s after first appearance. This would have greatly increased its surface area, and likely wasted a significant portion of its kinetic energy at that point. So the power delivery curve wouldn't be completely smooth or continuous.
That said, a nuclear device delivers virtually all of its energy as ionizing radiation (5%), thermal pulse (30-50%), blast (40-50%), and residual radiation (5-10%). The actual nuclear reaction takes less than 0.5 milliseconds, the thermal radiation pulse generally lasts several seconds, more for exceptionally large weapons (e.g.: Tsar Bomba, 50 MT).
The distinction between total energy delivery, and rate of delivery, is key. Gunpowder and TNT are actually significantly less energy dense than kerosene, but release that energy much more quickly. The destruction of the WTC towers in 9/11 was the result of aviation-fuel driven fires burning in a structure for many minutes, rather than a single explosive pulse.
The mode of energy delivery also matters. For a meteor, the principle delivery is heat, light, and shock. With nukes you've got both ionizing radiation and fallout to be concerned with (generally 10-20% of total energy).
This is also a point I raised regarding financial market collapses, when a professor tried to point out that the stock market had survived 25% declines before the 1987 crash. Sure, but over time. Would you prefer going from 60 MPH to zero in 4 seconds or 0.06 seconds (about the time it takes your seat front to find the front bumper in a static-barrier impact)?
Since we are talking total energy release, it becomes hard to compare them since a meteorite dumps a significant amount of it's energy into the atmosphere in a much slower and widespread fashion, whereas a nuclear device does it in one place at one time.
Now I'm pretty sure that if you get a big enough meteorite moving fast enough, the distinction becomes much fuzzier and the real important factor becomes just how much thermal energy was added to the atmosphere.
I believe it is because most of the damage done by a nuclear bomb is caused by radiation, not by the initial blast (do correct me if I'm wrong, I am by no means an expert).
Not really. The fallout can be a significant danger, depending on the bomb size and design. However, it's much easier to survive than the initial blast, in general. It can be a substantial problem for survivors, but the blast will kill far more.
The main reason the explosions aren't comparable is because this meteor exploded far higher than a nuclear bomb would detonate. By the time the blast reached the ground, the energy had been spread out over a large area. If it had exploded at a typical nuclear bomb detonation height (say, 1km or so), the destruction would have been comparable, although survivors wouldn't have to worry about finding shelter from fallout.
Now.we.know why we need meteor defense. If this rock ( that is.actually small ) ended hitting a 10 millions people city filled with glassy skyscrapers, what would happen? How many people.dead or in hospitals?
No, meteor defense can get in line behind heart disease, automobiles, suicide, gun violence, war, police, and all the other things astronomically (heh) more likely to kill people, therefore more deserving of our attention.
Heart disease and car crashes don't have the ability to derail significant economies in short shrift. There's pretty obviously a huge difference between singular, concentrated disasters and amortized "normal" human death.
I think that as long as we're talking about sub-extinction levels, I disagree with you.
WP estimates roughly one million car accident deaths per year (worldwide est for 2007). Heart disease numbers are more like 30M/year, although lots of those people were very old, so it's hard to estimate what's preventable. Compare that with a hypothetical meteor that kills one hundred million people, in a confined geographic area (that's 1/7 of Europe, or 1/5 of N America, or just half a dozen large Asia cities). What're the odds of that meteor? Even the once-per-millenium Tunguska event wasn't large enough to do that much damage. But suppose once-per-millenium meteors WERE deadly enough to kill 100M people, that's still 1/10 the deaths per year. If it's more spending-efficient to prevent the deaths from heart disease, do that. If it's more spending-efficient to prevent the deaths from meteor impact, do that.
On the other hand, extinction events are worth treating with extra care. Which in fact is exactly what meteor watches do, which is why they only look for entry diameters over 100m. Seems reasonable! Extinction events have happened 5 times in the last 540 million years. They're pretty rare. Maybe we should just roll the dice.
Off-topic: That's not what "shrift" means. Maybe you'd like "short order" or just the clearly "in a short time".
To be clear, I'm not actually saying that a meteor defense system is a reasonable idea. I don't know enough about the topic to say anything interesting.
My point was rather that you can't compare a catastrophe with disease / accidents simply in deaths-over-time. Catastrophes have dramatic economic consequences as well.
Okay, fair enough. I like the "I don't know enough to speak" attitude, and I don't know enough either. (What do you mean, five minutes on Wikipedia doesn't make me an expert?!?! :P )
My reply to your core point is that you can so compare (not least because deaths-over-time have dramatic economic consequences too). Maybe we're just gonna disagree about this one. :)
I believe that from a bang-for-the-buck perspective, Near-Earth Object monitoring is one of the better values. In the scheme of national budgets, it is CHEEEEEP to deploy a ground-based observatory capable of detecting threatening objects. To wit: http://www.planetary.org/explore/projects/neo-grants/2012da1...
If we have the observatories in place, we should have enough time to come up with a reasonable defense.
I believe if we're wiped out by one of these rocks, it'll be due to our own negligence.
Unless we knew about it literally decades in advance, there is little mankind could do (with today's technology) to stop a miles-wide inbound asteroid from hitting the earth.
Though there is a tradeoff in resources vs. other human concerns, I think the math is a bit more complicated. We're not only trying to guard individual human lives but the health of civilization. Just the knowledge that a major asteroid impact was imminent, with no way to address it in time, would be severely destabilizing to global society.
Well, not directly; any single impact certainly didn't hit and kill life forms all over the globe. They induced environmental changes that gradually caused species to fail to survive. "Sudden" in geologic terms means at least hundreds or up to tens of thousands of years. An intelligent species like humans can and will react and adapt in that kind of time frame. We're already on that path; we can already at least detect and predict any object big enough to significantly disrupt the planetary ecosystem.
> An intelligent species like humans can and will react and adapt in that kind of time frame. We're already on that path; we can already at least detect and predict any object big enough to significantly disrupt the planetary ecosystem.
We've detected such a series of objects and have willingly not tried to prevent them from dramatically altering our ecosystem, but are encouraging and quickening the damage they do. Detecting and predicting is not nearly enough. Action is required and there is absolutely no evidence to suggest that humans will take that action. I strongly disagree that a species such as humans 'can and will react and adapt'. So far we have shown that we are the exact opposite: we are the ones causing global environmental catastrophe.
This is a really bad comparison imo. The difficulty of sustainability and non-pollution is that it requires everyone to work together to not consume. If even a few parties decide to not cooperate they can consume everything that's left and the other people will lose out on their "share." In the case of an asteroid it's in everyone's interest to prepare as best as he/she can and cooperation actually helps. There's really no downside to preparing as much you as can.
Always love how people throw out "gun violence" as if "gun violence"(as if there is such a thing) is so distinguishable that it should be focused on above "violence".
"If someone gets into your house, which would you rather have, a handgun or a telephone? You can call the police if you want, and they'll get there, and they'll take a picture of your dead body. But they can't get there in time to save your life. The first line of defense is you."
quite frankly, the "gun in your house" thing is a very weird argument. if you actually play out a real-life instance of such a situation, it's not so simple at all. reality is much more nuanced.
for example, a gun is about 120% useless if you have it stored and the bad guy has the drop on you, which is likely the case on multiple levels given that that the 'bad guy' is the aggressor and initiator of a rare situation.
for example, the 'bad guy' may have a gun himself, and seeing you wielding one may cause him to shoot you, when he otherwise wouldn't have. and it's entirely possible or even likely that he has spent more time at the shooting range than you, or that he has killed people before. nevermind that he, having the mental preparedness that comes from being the initiator, may have the clearer presence of mind and less shaky hands
Etc. Etc. the "gun in my home to keep me safe" is a non-sequitur and only makes sense in simplistic cowboy scenarios, and I've even heard statistics saying you're more likely to hurt yourself or a loved one than the bad guy...
...but we don't really have any good ideas about that, because the gun lobby has suppressed research into these things for several years
> the "gun in my home to keep me safe" is a non-sequitur and only makes sense in simplistic cowboy scenari
No, it makes perfect, quantifiable, empirical sense
>> data from the United States, show “a negative correlation,” that is, “where firearms are most dense violent crime rates are lowest, and where guns are least dense violent crime rates are highest.”[1]
> No, it makes perfect, quantifiable, empirical sense
i disagree. the reality of a criminal entering someone's home where guns are involved is much more complicated and unpredictable than that argument implies. and i've also read of other studies that show the opposite conclusion of that study
now that the research ban has been lifted, we will get a better picture eventually
> That must be why there are so many homicides with other weapons in Western Europe and most of Asia.
I could never find a good response when my rational argument is met with an off-hand snark. And yet something should be said to avoid the perception that it was a valid counterpoint.
One option would be to point out that there are multiple factors at play, other differences between those countries than just gun ownership. That study after study linked in the post before show no correlation, no meaningful impact of gun ownership. That there are causes of crime that explain reality much better, like family structure.
Other would be to mock. "Sure, let's ban all the guns, jail all the blacks, and live in a crime-free utopia. Oh, and maybe nuke Detroit or New Orleans while we're at it. After all, nothing gives a better picture than a cursory glance."
You certainly do have a point. I'm Swiss and our gun ownership clocks in somewhere after USA and Canada, yet violence levels are about the same as in the rest of Europe. It really seems to have much more to do with culture than with guns themselves. However, defending this position must be quite tough as an American. It means that there is something inherently violent in your culture.
Maybe there is a correlation with suburban car culture? First there is the significant correlation between environmental lead during childhood and violence, secondly I think that having a low population density might make people feel more on their own, the highest goal being to protect their family. I'm thinking that people that are used to a high population density, who are in contact with hundreds of other humans a day, get used to this and lower their defenses. Then again I've seen a study suggesting that the violence leves in cities and on the countryside is pretty much the same (at least after lead levels have evened out).
Maybe, hopefully, the decline in violence in the US will continue and it will level out at a similar point as Europe / Asia - then we'll probably know that you were just poisoning yourselves with lead. I hope that this will have some impact on limiting the power of lobbies. Think of how much lead gasoline, lobbied into the world by the oil and car industry, has cost society, if this really was the main cause of the 70ies / 80ies crime outbursts.
The thing to recognize here is that Swiss culture is the exception, not the rule. Large parts of the rest of the world do not have a culture like the Swiss and would very likely end up like the United States if you flooded them with guns and ammunition.
The idea that the presence or absence of guns is totally divorced from gunviolence is ridiculous, motive, means and opportunity. Take away the bulk means of easily dispatching fellow human beings in your average culture and you see a decrease in violent deaths. See Australia.
I agree with you. I wasn't arguing against gun control laws. Actually, Swiss gun control is very strict, plus it's also not so easy to get ammunition. Most of the guns here are the military rifles people keep after service and the ammunition for those is unavailable - well except if you really really want it. Therefore it's not quite like people have constant access to a gun for those times when they get into the mood for murdering someone. I'm certain that more regulation in the US would help in that regard.
What I'm saying is: I'm skeptical that this alone would bring the aggression levels in the US to European levels (not even speaking about Japan, where it's another order of magnitude below). It would certainly be a good start though and it would be relatively easy to implement. Similar to software development: One should always start optimizing by getting the low hanging fruits.
It's still interesting however, to think about why there is such a cultural difference between the US and Europe, considering our heritage is so close.
> "If someone gets into your house, which would you rather have, a handgun or a telephone? You can call the police if you want, and they'll get there, and they'll take a picture of your dead body. But they can't get there in time to save your life. The first line of defense is you."
Of course, the flip side of this is "If you're horribly depressed in your house, which would you rather have, a handgun or a telephone."
Same thing for "If your teenage son's irresponsible friends are in your house..."
> Of course, the flip side of this is "If you're horribly depressed in your house, which would you rather have, a handgun or a telephone."
Not much a flip side. Unless you happen to think that suicides by other means are somehow better.
>> The evidence, however, indicates that denying one particular means to people who are motivated to commit suicide by social, economic, cultural, or other circumstances simply pushes them to some other means.[1]
"If someone gets into your house, which would you rather have, a handgun or a telephone? You can call the police if you want, and they'll get there, and they'll take a picture of your dead body. But they can't get there in time to save your life. The first line of defense is you."
I'm really curious about how this is meant to work in large cities, where there are often lots of people living in a small amount of space, with very flimsy walls between them and so on.
Surely firing a gun in such an environment is likely to cause yet more harm (with bullets flying through windows/walls), even if you do manage to hit the intruder?
Here[1] is an example of said ammunition. The corrolary, of course, is that if something won't go through an inch wall material (most of walls are hollow, after all), penetrating inches of skin, fat, and muscle are also unlikely. I've read of some people who put the first couple of rounds using the safety slugs and then hollow-points for the rest, figuring if somebody isn't going to stop with a couple, fairly large, relatively surface wounds, then they aren't going to stop without something more serious and house mates are in danger in that situation anyway.
Regardless, before I would ever keep a gun for personal protection[2], I would make sure I have enough experience shooting it and hitting my target that my likelihood of missing at short range is exceedingly low. Stress and all that will impact your abilities, of course, but enough training can significantly reduce that risk.
The idea is that, as a general rule, people will fire the gun if the situation is pressed. Knowing that, criminals will back down when a gun is presented. It's not bluffing, just threatening.
The essence of the argument is the emotional appeal of self-defense, which makes these considerations less important. Someone facing a violent intruder in their house is not likely to think about their neighbors. They are going to do whatever they can in that moment to defend themselves.
It's a tricky one. If I fire a gun, I put everyone living immediately around me at risk. If an intruder has a weapon though, does potentially disabling him or her outweigh the risks against everyone around me?
It's something I really struggle to work out, to he honest.
> The "guns save lives" argument falls apart when you realize that the plural of anecdote is not data.
No, not really. It works for real data, too.
>> Using cross-sectional time-series data for U.S. counties from 1977 to 1992, we find that allowing citizens to carry concealed weapons deters violent crimes and it appears to produce no increase in accidental deaths.[1]
Which never impresses anyone so gun advocates go for stories.
The problem is that enthusiast gun owners don't want to be able to deter intruders, they want to be able to stop gun-owning intruders from getting off their first shot, in the hypothetical that the resident can surprise the invader.
In discussions, 45ACP is thus favored for 'stopping power' versus the smaller 9mm. The gun-enthusiast response to the penetration concern is either to ignore it and emphasize aim & intelligent planning, or to create expensive 45ACP 'frangible rounds' that shatter into a granular powder on impact. There also exist somewhat anomalous theories about buckshot/birdshot being safer.
The most common guns, though, are lightweight, low-recoil 22LR-caliber pistols that lower the kill probability significantly over any of the more serious pistol rounds.
One can certainly create less-lethal loadings, either with traditional lead or something else like rocksalt shotshells, but things that can penetrate a chest cavity tend to be able to penetrate drywall.
I'd just go with a Taser and pepper spray if I was concerned about the small chance that penetrative shrapnel ends up energetic enough to hurt a loved one.
"There is such a thing as gun violence" I'm not convinced.
"It is distinguished as violence involving at least one gun."
re-read my post, i said
>> "so distinguishable that it should be focused on above "violence""
I'm not saying that it cant be distinguished (as others describe it), I am saying is there a big enough difference that we should focus on it over violence in general.
IN MY OPINION! focusing on "gun violence" takes away from the more important discussion on "violence" in general and diverts the discussion to matters non conducive to stowing violence in general. BUT this is not what this post is about.
I reread your post. It was the same as the first time I read it. It said "Always love how people throw out "gun violence" (as if there is such a thing) is so distinguishable that it should be focused on above "violence"."
Based on the bit I emphasized, you are implying "gun violence" is not a real concept, or doesn't exist, or something along those lines. Gun violence is real.
Further, OP is clearly not commenting on the prevalence of gun violence vs other violence. OP is commenting on things more likely to cause damage than a meteor strike.
Sure it's distinguishable. It's scarier, so it's easier to get people upset about it. People seem to be orders of magnitude more afraid that they will be gunned down as opposed to, say, killed with a knife or a hammer.
Only if we assume that our mitigation efforts against those other problems would be lacking for resources, if we sent some resources to work on space object detection/defense.
If we're putting as much money and effort into automobile safety as society wants/will allow, there's no 'loss' in taking additional funds to tackle the next problem down the line. And so on.
Except none of those things can realistically kill every person on the planet. Nuclear war would maybe be the only threat I think has a higher likelihood of making mankind extinct than a meteor, which is why graphics like this scare the crap out of me:
Although those things do kill more people every year, and they are predictable numbers. We have figured out how to get along. However a meteor is currently unpredictable, and we have no plan for what happens if it hits somewhere big. The effect of all the heart attacks next year have been taken into consideration, a meter or strike to London, less so.
Not to mention the infrastructure damage(not that i am belittling human damage). It would take years and billions of dollars to repair. Imagine every window in New York blowing out?
The secondary damage would be much worse then primary.
Something like this actually happened in Ft. Worth back in 2000. It was caused by a tornado. Walking along the sidewalks afterwards was terrifying, as you never knew if a shard of glass might come swooshing down towards your head. They did, however, create several wooden structures like painter's scaffolding that you could walk under for protection.
http://en.wikipedia.org/wiki/2000_Fort_Worth_tornado
It caused half a billion dollars in damage.
But you really couldn't have prevented it. Minimized damage, debatable.
Though i would have to imagine a meteor over New York(same strength earlier today) would be much worse, probably even a worse case scenario?(again for same strength).
Meteors of this size your probably right, no easy way to prevent them. But i would not say that its impossible.
My understanding is that all existing plans for deflection are wild-and-crazy and completely untested.
We'd be okay if we had 30 years of warning, because that's long enough to try multiple insane strategies, each of which takes half a decade to get working.
They're not all insane. Personally, I'm partial to the slow but effective gravity tow: send a small, 1-ton spacecraft and have it sit right next to the asteroid, without impact. If you place it correctly you can alter the orbit however you like.
Of course, the danger is that this could be used for evil, too. But it's not that crazy, and it would most definitely work.
We routinely land impactors, robots, and even sample return missions on other bodies in the Solar System. It does not seem to be a stretch to land a small rocket on a meteor and give it a push. If you do it a few years in advance, it would not even take much of a rocket.
When the mass you are trying to move is a billion metric tons, you're gonna need a lot of advance warning. We can land on asteroids, changing their trajectory enough to avoid a planet strike is uncharted and entirely unpracticed territory.
Part of me thinks that NASA's recent foray into asteroids is just that, practice.
We make sure there is enough money in the defence budget to send out Bruce Willis, Ben Affleck and gang on more training missions. Although I'm not opposed to just leaving Ben Affleck out there for a while.
We also need to come up with some treatment for space dementia. It almost ruined the mission last time.
Wouldn't the real problem with this be special interests? The country who develops it will not want to give it up to the rest of the world for obvious reasons.
I wasn't referring to the meteors themselves... but rather the technology that can track/intercept them. I imagine it could be used for other things also.
It's pretty fortuitous that so many folks in Russia have dashboard cams. I've got to think this is a meteor impact that has the most independent, distributed points of view that were dutifully recorded.
They keep saying "explosion" but was there actually one? There was a sonic boom, and the rock disintegrated in the atmosphere, but I've not seen any evidence that it exploded all at once.
EDIT: well, lots of news agencies are using the word "exploded", so maybe it did. I see somebody else mentioned claims that Russians shot at it, but I'm skeptical that they'd be able to notice and react to this thing in time.
EDIT EDIT: OK so it looks like space rocks "airbursting" is not unheard of: [0]. Really curious what the physics of that involves.
Is is not an oxidized detonation explosion in the traditional sense, it's a hypersonic solid-gas fragmentation impact.
In this case, the most intense period involves peak pressure. The meteor falls down, encountering gradually thicker air, heating up and heating up, until finally, the pressure and differential internal stresses are sufficient to separate it into smaller pieces.
These smaller pieces are a lot less massive per surface area, so the pressure acting on them is going to be a lot more relative to their mass, and they are going to slow down much faster. The deceleration while this is going on, then, is going to induce sufficient turbulence to break them up even faster. So the breakup occurs in a sort of chain reaction, and the pressure waves from nearby fragments influence each other, adding turbulence and slowing the cloud of fragments further, until it all ends up as small particles spread over a large area. These particles are moving for the first fraction of a second of their life at supersonic velocities, generating a very large pocket of vacuum / shockwave as they dissipate their energies. The rapid expansion of the largest highly vulnerable layer of the asteroid into a cloud of dust thus constitutes an 'explosion', even if the energy is all kinetic instead of the slow chemical burning that happens afterwards as the white-hot particles oxidise & turn to ash.
Asteroids are not uniform, however. Wrap a chunk of granite in a chunk of sandstone, and you may end up chipping off bits of the sandstone for 10s, heating up until all the white-hot sandstone flies off in fragments at once for 2s, and then the granite flying further towards the ground until its yield strength is exceeded in a higher pressure regime, or it impacts the ground. With complex structures, multiple waves of fragmentation are possible, and rather than being a simple matter of the fragments immediately dissipating into small particles and a harder core, a meteor will tend to split into chunks which themselves become smaller examples of this phenomena.
Refreshingly honest. And that's probably true for the planet, not just for Russia. You can bet there will be a lot of people using this incident to try to get funding so they can go play while pretending they are going to save the planet at some unspecified future date.
EDIT: Just saw Bill Nye explain this on the DA14 webcast from planetary.org. When the meteor hits the atmosphere at such a high velocity, it's like hitting a brick wall and it explodes on impact. Then the shock wave propagates to the ground as the fragments fall and oxidize.
IIRC, the meteor can also explode due to the core heating up from the atmospheric friction, though this depends on the make-up (materials, density, configuration) of the meteor.
NASA's just confirmed this story on their twitter feed.
>>>@NASA #RussianMeteor is largest reported meteor since Tunguska event. Impact was at 3:20:26 UTC. Still being measured. More info to come.
That is an interesting point, If this had travelled over one of the poles would we have noticed? I tend to think that someone would have seen it, but we wouldn't have a dozen dash cam videos of it.
The infrasound detectors mentioned in the article can supposedly detect a 1-kiloton blast anywhere on earth [1] (page 15). This meteor was "hundreds of kilotons".
It also would show up on satellites that monitor for rocket launches and nuclear explosions. But whether or not the details would be released to the public is not entirely certain.
That's true - we would detect it now. But the CTBTO International Monitoring System is a relatively new development (design and construction didn't start until 1997).
Its interesting coincidence i suppose that there is going to be a close flyby of a near earth asteroid on Feb 15th. Even google changed their doodle to remind that (but the doodle is gone now!)
Can anyone comment on why we don't have a handful satellites sprinkled with cameras pointing at all directions orbiting the Earth and feeding data down for analysis? Perhaps it's not much, but something is better than nothing. The excuse that this meteor wasn't spotted because it came from the sun side is laughable.
There are a lot of asteroids in the Solar System. Millions. The solar system is huge. It's not laughable that this one wasn't seen - it was extremely tiny.
Most asteroids that we can detect we do not have the technology to deflect unless we discover them decades before impact. Even then, deflecting them is all theoretical and would be a monumental technological undertaking, as it has never been attempted before.
Sounds like a wonderful Kickstarter project. Seriously though, the cost/benefit ratio isn't worth it for detecting stuff this small. "Worst in 100 years" and there was virtually no damage.
True. There are programs actively looking for larger objects though, that you can donate to if you're interested. This is the one that found 2012 DA14 which will be passing us shortly:
And there was no link to the other meteor that passed earth today ??. Or did Nasa coverup that it didnt knew what trajectory it would take. It seams unlikely to me that those two events are not related.
I mean recently Nasa found some anomaly on Mars too, and then they say "no its not interesting its just erosion; (mars has next to none atmospheric pressure btw) i mean if i where a geologist, then any curious shape even if it was made by erosion would attract my attention i would take samples; and most likely such samples would be more interesting then dust-hole digging. What has become from NASA i wonder. Once they where explorers curious.. now they only call their device curiosity
> Are there certain geographies or areas that are more prone to these incidents than others?
No. An incoming meteor or asteroid is perfectly ecumenical with respect to location, therefore the vast majority of meteors fall into the oceans.
On a related note, the best time to see meteors is between midnight and dawn in whatever location you find yourself. The reason? At dawn, if you look straight up, you're looking in the direction Earth is moving in its orbit at thirty kilometers per second. By contrast, if you look straight up at sunset, you're looking at where Earth has just been and is receding from at thirty kilometers per second. Earth's velocity is added to that of the wandering space rocks near dawn, but is subtracted at sunset.
It's unfortunate this event is a wake up call. 99% of Near Earth Objects (NEOs) are unknown. We at the B612 Foundation (http://b612foundation.org) are building a telescope for early warning detection. Everyone can get involved. Please visit our site to learn more... you can help!
Russian state TV claims that the meteor was intercepted by an anti-ballistic missile system, which (if true) means the meteor was struck by a 10kt nuclear warhead.
USA Today has a decently balanced assessment of the incident. Apparently Russia Today was "informed" of that. However the deputy prime minister has countered that by stating that "Russia does not have the capability to shoot down meteors."
Isn't it quite a coincidence that the largest meteor impact since 1908 occurs just hours before the closest fly-by of a large asteroid in 100 years? Yet, NASA claims these two are unrelated.
I'm very intrigued by this too. The consensus though seems to be that they came from completely different directions... here's a diagram that's making the rounds in Reddit[1]. It looks like this meteor landed in Russia hours before 2012DA14 even came close to being inside the moon's orbit, which makes it hard to imagine how one could have affected the other.
They are going in nearly opposite directions and are roughly a million miles apart from each other. Once you get a real idea of how empty space is (all of the not-to-scale diagrams you get in high school are no help here) it's harder to see how they could be related than not related.
True random distributions just work that way. If something that's supposed to happen once in a hundred years is spaced out at roughly 100-year intervals, that's not random.
Yea I find this curious as well, what are the odds of that happening? How many other chunks of rock could be heading our way right now that are too small to be spotted?
I don't know but I do really hope that the one that hit Russia wasn't part of a smaller but faster one that did actually hit 2014-DA and change its course.
Otherwise the northern emisphere is in trouble.
I find that coincidence very, very weird too.
And you gotta love all the people saying: "Nothing to see here, move along", as if they had themselves ran all the computation and knew for sure there was no relation between the two events.
One day, driving home I happened to look out at something I thought was a plane and nearly drove off the road as I saw a meteroid falling silently through the sky. There was absolutely no sound and it moved much slower than I expected. After I regained control of my car and pulled it over to get out and watch, I saw small pieces silently broke away and the light show continued until it went over the horizon. It was totally unlike anything I'd ever seen before or since. It's dreamlike and beautiful.
I waited a few minutes after it went below the horizon since the angle it went on made me think it might have made it to the ground, but I never heard anything. It was never in the news, and nobody talked about it afterwards, for all I know I'm the only one who ever saw it. It was both terrifying and amazing. I had no idea what I was looking at since it didn't look like any picture of this phenomenon I'd ever seen.
One thing I'm sure of, is that I've never seen a video that ever does such a spectacle justice. There's so many subtle details that get completely obliterated on video.
Here's some video that do a pretty good job of showing what they look like.
http://www.youtube.com/watch?v=GWhrW7lpqZM http://www.youtube.com/watch?v=dyW0g1SIyxI
The videos of the one in Russia are on an entirely different scale. The sonic boom was tremendous, the amount of light being thrown off of that thing was unbelievable. Extrapolating from what I saw and how I now know video changes things, this must have been an unbelievable beautiful and terrifying sight.