Whoa! A close shave next year.

[Speed]

http://www.space.com/14810-asteroid-earth-impact-risk-2012da14.html

 

It looks like the asteroid 2012 DA14, discovered a week or two ago, will come within about 20,000 or 30,000 kilometers of Earth next February. It will pass well within our ring of geosynchronous satellites, maybe closer to the altitude of the GPS constellation. If its track was only very slightly different, we'd only have a year's warning to prepare, and no real idea exactly where it would hit. It is estimated the object is about 45 meters across, roughly around the estimated size of the object that hit Siberia in 1908 with the explosive power equal to some of the most powerful nuclear devices ever detonated (thankfully, Siberia is Siberia, so it only killed reindeer and trees). We might not be so lucky the next time.

 

To my knowledge, this will be the closest approach of a destructive asteroid we've ever had advance warning of. Apophis will come about as close in 2029, though, and it's a much larger object.

 

Maybe it's time to start investing in asteroid deflection technologies? :huh:

Edited March 7, 2012 by Speed

[asparagin]

This would be a good opportunity to test the readiness state.

[Togg]

Not sure if it's possible to deflect it with this short deadline.

 

 

[asparagin]

Let's just say that in that case I would invest in bunker technology.

[Speed]

Not sure if it's possible to deflect it with this short deadline.

 

 

 

I know that the nuclear option is usually frowned upon, and actually is not a very good option for bigger objects, I would think that in this case, the small size of the object would make it deflectable with nukes. It's only 45 meters across! But another question is- when would we be able to reach the object? It's heading away from us a high speed right now, and the next pass is the close approach of next year.

[Pyroflash]

IF you know when it is going to hit, then you can launch it in a elliptical orbit of the earth WELL in advance of the projected impact. That way the nuke is already in place and all the asteroid has to do is keep circling. Shouldn't be too difficult for our scientists to figure this one out. Hell, you don't even need a nuke, even for a bigger object, all you really need to do is nudge it off course by a fraction of a degree and it will miss by a good distance at the range you'd likely intercept it at.

Edited March 7, 2012 by Pyroflash

[Togg]

Hell, you don't even need a nuke, even for a bigger object, all you really need to do is nudge it off course by a fraction of a degree and it will miss by a good distance at the range you'd likely intercept it at.

 

But you have to start to nudge it several years before the impact, depending on the mass.

Edited March 7, 2012 by Togg

[Speed]

IF you know when it is going to hit, then you can launch it in a elliptical orbit of the earth WELL in advance of the projected impact. That way the nuke is already in place and all the asteroid has to do is keep circling. Shouldn't be too difficult for our scientists to figure this one out. Hell, you don't even need a nuke, even for a bigger object, all you really need to do is nudge it off course by a fraction of a degree and it will miss by a good distance at the range you'd likely intercept it at.

 

Right, but their are a few advantages I think the nuclear approach might have:

-Could be ready on relatively short notice.

-We've got a lot of them, already.

-A kinetic impactor could potentially cause the asteroid to break up-especially if it's a rubble-pile type like Itokawa- and maybe the big pieces still keep heading for an earth collision. A nuke could provide a more uniform push, perhaps (I guess the primary force transfer process from the nuke to the asteroid would be x-ray/gamma ray radiation pressure?).

[Wichid]

How could we use a nuke? Has anyone thought of actually building a nuke capable or heading out into space? I don't think you can just tell an ICBM to go off to an asteroid. They want street addresses. All the current ones just circle the earth to attack other countries. I think I heard about a russian initiative a while ago.

 

No one can build a saturn 5 rocket either as 100,000's of parts aren't manufactured anymore.

[Speed]

How could we use a nuke? Has anyone thought of actually building a nuke capable or heading out into space? I don't think you can just tell an ICBM to go off to an asteroid. They want street addresses. All the current ones just circle the earth to attack other countries. I think I heard about a russian initiative a while ago.

 

No one can build a saturn 5 rocket either as 100,000's of parts aren't manufactured anymore.

 

That's correct, you can't just use an ICBM. However, the technology to build a space craft to go rendezvous with an asteroid or comet, and then orbit it, hover over it, land on it, or even impact it, is very well established. I know it takes a very long time to develop these space probes, but hell... you don't even need a new design really. If push came to shove, I don't see any reason why it couldn't be done.

 

With this case though... I wonder if we'd just take our chances with it, rather than go through all the expense and trouble. Chances are, it would hit over the ocean, which wouldn't be a problem (it's too small to cause a tsunami). Even if it hit over land, we'd probably have weeks to figure out exactly where and evacuate everyone in the at-risk area. Still would suck if it hit a big city, evacuated or not.

[cichlidfan]

Still would suck if it hit a big city, evacuated or not.

 

Yeah, even if you weren't home it would suck if it hit your house. Somehow I doubt your basic homeowner's policy is going to cover it.:D

[Depth]

(thankfully, Siberia is Siberia, so it only killed reindeer and trees). We might not be so lucky the next time.

 

 

Yeah hopefully this one will miss the U.S.A. and hit Norway, where it will only kill fjords and mountains :huh:

[Grimes]

That's correct, you can't just use an ICBM. However, the technology to build a space craft to go rendezvous with an asteroid or comet, and then orbit it, hover over it, land on it, or even impact it, is very well established.

 

Its to late for the 2013 asteroid, but I've read that if they calculate the 2029 asteroid would likely impact us one of the options is to simply launch a probe that has quite abit of mass, park it next to the asteroid, and the proximity of the probe would cause the asteroid to slowly drift off its trajectory.

 

Alternatively we could just send Bruce Willis up and hope he figures something out.

[EtherealN]

If its track was only very slightly different, we'd only have a year's warning to prepare, and no real idea exactly where it would hit.

 

Depends on what exactly you mean by that. We've had cases where a previously unknown object is discovered and actually strikes ground within the day - with the location of impact known ahead of time and suitable warnings issued. (Though if I remember right it struck a desert in Kenya, so no grand-scale evacuations were necessary.)

 

For an object that is a year out from impact, sure, we'd not know exactly where it will hit, but if it became certain (or highly probable) that an impact will occur, you bet it will be followed closely and as the impact gets closer better and better estimates of impact sites will be made.

 

Regarding the nuclear option - yes, radiation would be the effect, assuming you don't make the weapon hit the object directly. But regarding how effective this would be, remember that even though the object is smaller and thus easier to affect with a nuke, it is also... smaller. So it will receive less of the radiation unless you make the nuke get even closer - at which point you might well hit it instead, whereafter you've arranged for a shotgun. As a last resort, perhaps. But another thing to take into consideration regarding gravity tugs is that while it might take a decade or three to nudge a large object with whatever mass tug you can get up there, a smaller object will be affected faster. Would be interesting to see how that works out for an object like this - the times I've seen gravity tugs considered were more for objects like Apophis, and that rock is many orders of magnitude more massive than something like this.

[Pougatchev]

Russians are "apparently" on the way.

 

I have read that on news24:

2012-02-24 20:44

 

Moscow - Russian rockets tipped with nuclear weapons could be used to intercept asteroids on a trajectory for a catastrophic collision with Earth, officials at the Russian aerospace research institute said on Friday.

 

Russia's veteran Soyuz-2 booster, and its even bigger planned replacement, the Rus-M, could be used to divert or destroy an incoming asteroid up to 700m in diameter, said Vladimir Degtyar, director of the Makeyev State Rocket Centre (MSRC).

 

Smaller asteroids would be shattered by explosions set off on a planetoid's surface, while the flight path of larger asteroids could be shifted with nuclear detonations adjacent to them, Degtyar said.

 

Russian scientists have researched the technologies needed for the project and believe it to be workable. However, additional Russian government funding is needed to develop a functional anti-asteroid weapon, Degtyar was quoted by Interfax news agency as saying.

 

MSRC technicians have also developed plans for a reconnaissance rocket that would fly to a potentially threatening asteroid to determine its mass and make-up, prior to the launch of nuclear-tipped rockets.

 

Asteroid collisions with the Earth are extremely rare, with almost all of them breaking up in the atmosphere.

 

Scientists have suggested an asteroid that fell near Mexico's Yucatan peninsula some 65 million years ago triggered tremendous climate change and caused the dinosaurs' extinction.

 

- SAPA

[Speed]

Depends on what exactly you mean by that. We've had cases where a previously unknown object is discovered and actually strikes ground within the day - with the location of impact known ahead of time and suitable warnings issued. (Though if I remember right it struck a desert in Kenya, so no grand-scale evacuations were necessary.)

If you're referring to the object I'm remembering, it was only like a few meters across and so exploded harmlessly high up in the atmosphere.

 

 

Regarding the nuclear option - yes, radiation would be the effect, assuming you don't make the weapon hit the object directly. But regarding how effective this would be, remember that even though the object is smaller and thus easier to affect with a nuke, it is also... smaller. So it will receive less of the radiation unless you make the nuke get even closer - at which point you might well hit it instead, whereafter you've arranged for a shotgun. As a last resort, perhaps. But another thing to take into consideration regarding gravity tugs is that while it might take a decade or three to nudge a large object with whatever mass tug you can get up there, a smaller object will be affected faster. Would be interesting to see how that works out for an object like this - the times I've seen gravity tugs considered were more for objects like Apophis, and that rock is many orders of magnitude more massive than something like this.

The reason you can't use a gravity tractor on this object is that you would only have like months for the gravity tractor to operate, and even more importantly, we haven't even built a gravity tractor. They don't exist. I'm talking- here and now- if we had to send a deflection mission, what other options would there be other than a nuke or a KE impactor?

 

And furthermore, maybe a nuke would be a little more immune to the "shotgun" effect than say, a kinetic energy impactor would be. The blast (or radiation pressure) would be be much more evenly distributed across the object. Even if the object still broke up, each piece should receive some push from the explosion- especially if it were possible to time a second nuclear blast to occur right after the first. If such a thing were possible, you could potentially give the rock pile a push with the first nuke- if the first nuke causes it to break up, the second nuke might hit all the broken up components at once as well. Can't do that with a KE impactor. But could you get the second nuke to not be destroyed by the first? I would think so, as they could be separated by quite a distance, at the speed these things move at.

 

And finally. If you break an object this size up- that's not bad either. Perhaps the smaller components will break up higher up in the atmosphere, and do no harm.

Edited March 8, 2012 by Speed

[EtherealN]

If you're referring to the object I'm remembering, it was only like a few meters across and so exploded harmlessly high up in the atmosphere.

 

Which is not relevant to the point I made. ;)

 

I'm talking- here and now- if we had to send a deflection mission, what other options would there be other than a nuke or a KE impactor?

 

We have the option to not send a deflection mission at all.

 

And furthermore, maybe a nuke would be a little more immune to the "shotgun" effect than say, a kinetic energy impactor would be. The blast (or radiation pressure) would be be much more evenly distributed across the object.

 

Which, unless we know the object's structure and material nature very very well, which is highly unlikely given the time pressure assumed for the scenario, might be even worse. Asteroids aren't necessarily just a solid piece of stone and iron.

 

Before considering the risks imposed by a given weapon, we'd have to actually know what the effect of the weapon would be.

 

And finally. If you break an object this size up- that's not bad either. Perhaps the smaller components will break up higher up in the atmosphere, and do no harm.

 

I'm not sure I want to trust a "perhaps" for something like this.

[Speed]

Which is not relevant to the point I made. ;)

 

We have the option to not send a deflection mission at all.

 

 

Not sure what you're referring to. Just to be clear, I'm referring to the situation where a very small, but still locally devastating, asteroid was detected on a certain collision course with earth in one or two years time- a situation we came very close to this week, apparently.

 

 

Which, unless we know the object's structure and material nature very very well, which is highly unlikely given the time pressure assumed for the scenario, might be even worse. Asteroids aren't necessarily just a solid piece of stone and iron.

 

Before considering the risks imposed by a given weapon, we'd have to actually know what the effect of the weapon would be.

 

 

 

I'm not sure I want to trust a "perhaps" for something like this.

Eth,

I'm aware of the nature of asteroids, and how many are rubble pile objects- that's why I mentioned Itokawa in an earlier post:

 

My point is- we don't get much warning for the smaller rocks, and furthermore, I don't think this "you might make it worse", "nukes don't work", "you have to be careful" mentally really applies to the little stuff, like the 45 meter wide object just detected (not the above pic, the object that will pass close to earth next year). Remember that even if you do break it up, and every single piece you break it into STILL hits earth, you might have made all the pieces small enough to explode at a harmless altitude. Furthermore, if all you needed to do was deflect it away from a populated land mass, and you give it a slight budge, and it's still going to hit some random spot on earth, you basically just re-rolled your chances and you have a fresh 70% chance for the thing to explode over the ocean (which would not make a tsunami). I guess a worry could be, if the thing was a solid nickel-iron (those objects should be able to make it intact to the surface, at orbital velocities, at a much smaller object size than other classes- look what happened in Arizona 40,000 years ago), then I wonder what the smallest nickel-iron solid object would be that would cause a significant tsunami?

 

Sure, be careful... you probably wouldn't want to deflect a nickel-iron from Siberia to the Atlantic ocean- but I think it's much less important here.

 

Other than nukes, the only other sudden impulse method I have ever seen mentioned is a KE impactor, which, well, wouldn't it be? actually much tougher on the structure of the asteroid, and more likely to break it up. With a nuke, you distribute the force across a wide area, with a KE impactor, it's all in a tiny point. It seems obvious that for the same total delta-V, the nuke would be the gentler approach.

 

With the bigger stuff, assuming it's not a comet (if it's a comet we could be totally screwed), we should get a several decades, even centuries of advance warning, and we can build all the gravity tractors we want, even perhaps coat the surface or parts of the surface of the asteroid with a white substance (changing the momentum received from solar radiation/re-radiation). It could be as simple as effectively spreading flour on the surface of the object. Anyway, I think we're pretty safe from the non-cometary bigger stuff anyway at this point, I think I remember reading that the goal of detecting 90% of the NEOs bigger than 1km in diameter has been met.

 

Anyway, I just think that folks are taking the stuff said about the unsuitability/inefficiency/problems of using nukes for asteroid deflection, meant for larger objects and applying it to the wrong class of objects here. I can't see a reason why we can't just "have our way" with the really small stuff. Hell, we're talking about setting off a nuclear bomb, perhaps several nuclear bombs, each in the hundreds of kilotons range or higher, within a few hundred meters of a 50 meter wide object.... it defies all common sense that you wouldn't be able to change its velocity by enough to make it miss an earth collision a few weeks away. And even if you broke it up- then guess what, suddenly it's no longer a threatening asteroid.

Edited March 8, 2012 by Speed

[EtherealN]

Not sure what you're referring to.

 

I was responding to this:

"If its track was only very slightly different, we'd only have a year's warning to prepare, and no real idea exactly where it would hit."

 

The nature of the impactor and what damage it did and did not do in the mentioned occurance is not relevant to the question of when and how the impact site can be determined.

 

Remember that even if you do break it up, and every single piece you break it into STILL hits earth, you might have made all the pieces small enough to explode at a harmless altitude.

 

And that is my point - that might be what we do. And if it comes in hot and fast and without prior knowledge, and we know for certain that it'll hit New York... Then it's worth the risk. If it will land in the middle of sibiria or just glass some dunes in the sahara, I'd say it's better to let it land rather than start playing with uncertainties. And that ties back to the whole landing site issue that I originally responded to - the closer the object is to impact, the more we know. If it actually comes in hot and fast with "only" a year, we'll have a pretty good idea to start with and it will become clearer with time - again, remember, this is a calculation that is done automatically for every detected object - which is what the Kenya impactor was about.

 

Now of course, there's people that are way better qualified to answer those questions than either of us two, but I'm basically saying that if it's me making the judgement and what I have to go on is a "maybe" and a "perhaps"... I wouldn't risk it unless the impact is assured to be a tunguska-style city-killer or something similar.

[Speed]

If there's any other sky watchers out there, here's a nice, to-scale image of the asteroid's path next year:

 

Looks like, based off the GMT times, it will be visible only from Europe, Asia, and Australia. Maybe Africa too. I haven't seen any magnitude estimates, but doing a quick, back-of-the-spreadsheet calculation, verifying my formula with the known full moon brightness, and plugging in common asteroid albedos, I think the object will have a brightness of between visual magnitude 5.5 and 7- so either a it will be visible naked eye as a very faint star or easily visible in binoculars. Guessing off the graphic that it will cross about 60 degrees of sky in an hour, then its motion should be apparent to the naked eye (at like 1 arc minute a second), if it IS bright enough to be seen naked eye, that is. This also assumes no orbital uncertainty remains, and the close approach is 28,000 km.

 

Even if you’re not a regular sky-watcher, you might be interested in seeing it, but keep in mind that it will most certainly be too faint to be seen naked from inside a decently large city, and it will look like no more than a faint star. It will not be resolvable with backyard telescopes.

Edited March 8, 2012 by Speed

[Depth]

If there's any other sky watchers out there, here's a nice, to-scale image of the asteroid's path next year:

 

Here's hoping for no clouds :holiday:

[rextar]

Oh guys come on relax........

Bruce willis will deal with it lol !

[EtherealN]

Here's hoping for no clouds :holiday:

 

Word. Don't want to program the 8-incher and then just get a picture of clouds. :P

[edward1976]

Badly calculate, really time = 21 dec 2012 :)

[Pilotasso]

45m is small, it would be dangerous for people on the ground but wouldnt be any more catastrophic than the disasters we´ve seen in the recent past. We would survive and rebuild.

 

Shattering asteriods is a bit silly, first because in order to be an extintion level even the asteroid would have to be much bigger, second because Nukes dont cause a sockwave in space, only a very hot dot. Sending it againts a big rock wouldnt do any more than a smudge Im afraid. I guess we would have to waif for something with extra oomph like anti matter bombs :eek:, or gently propel it out of the way using rockets. it only takes a small push to have a big efect when distances are huge with weightlessness and when the warning cames years before.