"tractor beam"
Will you STOP using this wildly inaccurate description of the actual proposal !
A new international consortium has been set up to figure out what Earthlings could do if an asteroid came hurtling towards the planet on a path of imminent destruction. The project will look at three methods of averting disaster: the Hollywood-sanctioned solutions of sending up a crack team of deep drillers with a nuclear bomb …
Edgy :-
"daringly innovative; on the cutting edge. "
Your point is ?
And I have been on this site for a number of years. And there does seem to be a tendency for posters to get their facts wrong - often wildly so.
Recently someone claimed that the NEO was 6 miles in diameter where most info sources were saying ~11m or bus sized
and it's a complete waste of money.* Anything that small will pretty much burn up on entry into the Earth's atmosphere, assuming it doesn't bounce off because it came in at the wrong angle. It's only the ones that would require a nuke that you need to worry about.
*Although I suppose from the politician's point of view that makes it even better, because nothing bad happens from failure, and when if the project keeps failing, you can keep asking for more money. ... Maybe that's why they included the Star Trek style tractor beam too.
Don't know what you read but the report(PDF) calls it a 'gravity tractor' approach. That does NOT mean tractor beam (scifi) it just means flying near it and slowly adjusting it's trajectory by using the tiny gravitational attraction between it and the 'tractor' to provide the virtual 'grappling iron' . As the report suggests this approach will need years to have an effect.
Has nobody thought of playing billiards with NEOs? Could we not build some nice big billiard balls on the moon (Newt will help you there) and fire them at any threatening NEOs using a giant cue?
Put the right spin on it and you could probably get two at once.
In all seriousness I think these people are playing up the threat from NEOs just a tad to try to improve their funding.
"Oh, I've heard of worse," said Ford, "I read of one planet off in the seventh dimension that got used as a ball in a game of intergalactic bar billiards. Got potted straight into a black hole. Killed ten billion people."
"That's mad," said Mella.
"Yes, only scored thirty points too."
The Restaurant at the End of the Universe - Douglas Adams
Soft land on the object with your tail in the 'air' and start pushing.
Rockets are good for lots of sudden thrust, but painful to send all the fuel needed - ion drive is vice-versa.
This approach would be suitable for most kinds of problematic asteroids as long as you can do a sufficiently soft landing.
It gives more control as well I would have thought, unless the object is rotating of course .. hmm I might have to think about that some more I suppose...
ttfn
A thruster approach is the preferred approach to a NEO confirmed to be on collision course with a number of years notice (probably about five or so). Not only would it take time for the thruster kit to intercept the NEO, it would also need enough time for the slow, gentle push approach to have the desired effect.
The solutions being proposed here are probably for near-emergency situations (say, a doomsday comet gets confirmed with only a year's notice or less--think the 2012 predictions).
PS. To El Reg, the proper term (in the Trek universe) for a force beam intended to push something away from you is a REPULSOR beam. At least one other universe I've read has used the term "pressor beam" for the same thing, but the idea is you don't want to attract the object but repel it away.
But I suspect that they are talking about parking a massive object (ie one that has sufficient mass to do the job) near to the NEO and let the gravitational attraction between the two objects pull the NEO away - or towards the sun I suppose, as long as it's going to miss our blue marble.
ttfn
"That is indeed what is being proposed although the object would have active propulsion to slowly 'tow' the NEO away from a collision course"
That sounds like a *really* big lump of matter, given the force of gravity. It seems pretty hard to believe moving something that big would easier than moving the NEO itself.
It does sound fanciful doesn't it ?. Nevertheless that is exactly what is being proposed in the document referenced in the article under the title "Gravity Tractor"
"..minimize fuel consumption and maximize the asteroid’s deflection? What are the trade-offs between the mass of the tractor, the distance between the tractor and the NEO, the control laws, and the time required to produce the required deflection? Reliability is a crucial issue given the long periods (several years to a decade) typically required for gravity traction to produce the required deflection. What are the requirements for autonomous spacecraft control procedures to manage hovering station keeping and maintain stability of the traction system over a long period of time in the (verynearby) presence of an irregular rotating mass?"
the issue is that the NEO may not be easy to 'get a hold of'. it may be a loose collection of rubble, for example, or spinning wildly.
in that case your large 'gravitational attractor' (read: huge lump of moon rock with rockets attached) is already under your control - you 'just' park it near to the NEO you want to influence.
the Enterprise was using a tractor beam in an attempt to pull the asteroid out of the path of the planet. But it failed to suitably change the course of the object and they need the deus-ex-machina repulsor beam on the planet to save the day. Never understood why they didn't use the photon torpedoes myself. Split it up into little bits, move the dangerous chunks out of the way, and don't worry about the rest.
"The first problem here will be to stop everyone freaking out when someone fires off a nuke by making sure nuclear response is internationally coordinated."
I would imagine it's quite easy to distinguish between a missile aimed at Moscow/Washington and a rocket equipped to reach escape velocity and enter, at the very least, Earth orbit, before a second stage takes it into outer space.
We are not talking about shooting down an asteroid as it enters the atmosphere over the Pacific. By that point it's game over, far too late,
Eventually it is, but not shortly after its being launched. Because in the first stages the rocket will go up, no matter where its destination lies. If the target is on earth it will eventually change its course and fly in the right direction.
However; most countries would already be on full alert even before the rocket has changed its course. Because the quicker you can intercept such a missile the better. And that's not even mentioning retaliation.
I would think that its vital that they hang around to see where the target is. It's hardly a trivial detail
Otherwise the day Pakistan nukes India, the US will nuke Pakistan, on the assumption it was for them, at which point Russia will nuke the US, on the same basis, and China will nuke Russia, who'll be nuked by Britain, who'll be nuked by France, who'll be nuked by North Korea, who'll be nuked by South Korea, just on reflex.
Kind of like a western bar fight where no-one cares whose swinging at who, everyone just joins in.
quite similar. They'd be launched from the same facilities and are space vehicles not merely rockets flying through the atmosphere. I'm not sure how much extra boos they'd need to break orbit. Initially I was thinking you'd need something Saturn V like, but the exploration satellites don't need launchers like that, so nukes wouldn't either.
On the other hand, if you are talking about a year or more before impact with Earth, there's plenty of time to arrange the nuke launch and clear it with everyone.
I think it's simpler than that, you know. Getting something to an asteroid by definition needs something that can get out of the gravity well, which again by definition means a much bigger rocket than anything in the nuke arsenal. (As you say, if it gets close enough that a regular ICBM could hit it, then we're screwed.) So the easy way to tell if it's a nuke destined for an asteroid is bcos it's sat on top of a sodding great multistage rocket at Baikonur...
Pushing it in pretty much any direction can make it miss - the first time, anyway.
The key is to decide which direction to push so that we can (a) actually do it in the time required and (b) ensure it's not going to hit the Earth in the foreseeable future either.
- It would be fairly annoying to nudge an asteroid so it misses on the way in towards the Sun, but smacks straight into us on the way back out...
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...but given our amount of knowledge on manipulation of fundamental forces like gravity (which is zero), something like a Mass Effect, a Gravity Field Generator (from the Andromeda universe, does the same thing), or maybe a Bergenholm Inertia Neutralizer (been reading some OLD Sci-Fi) seems a long way off right now.
I share the Sagan view that such technology should not be developed. The ability to deflect a asteroid that presents a danger is also the ability to shift a harmless asteroid into a weapon. While far less wieldy than good ol'-fashioned nuclear annihilation, it's also not needed. A much better investment would be in asteroid detection systems. Time to react is the most critical determination in almost all planetary defence strategies.
Time to dig a hole, bury your head in the sand?
This is much like saying that if you detect cancer 6 months earlier, you'll live an additional 6 months after detection. This would be integer math, and the article is about changing the equation.
Your luddite views could be applied in ever so many other places. Computers can be used to calculate ballistics! They're a weapon! Ban them! Rocks can be used as weapons! Ban them! People can say mean things about each other! Ban talking!
... has someone been re-reading the Clarke classic 'Hammer of God' again?
If so, that's great. Develop big dirty great engines for spaceships. Easy.
The biggest problem, according to the book, will be stopping nutters from sabotaging the entire thing in the first place...
Why not simply build an antimatter cannon, this would obliterate the NEO in a lovely big explosion full of booms and whooshes with an accompanying fireball and finally a white fwoooooooom with a ring of light that will shoot out across the solar system.
CERN could supply an almost endless amount of antimatter material and I'm sure the merkins have some sort of laser cannon that could be modded by er lets say Mr T and the rest of the A team.
If that fails all we need to do is shift the earth out of the way by getting all the cars in the world to accelerate the same way at the same time thus pushing the earth slightly away from the sun. Sorting out global warming! and saving everyone!
Of course while this is going on the team in charge of all of this needs 1 old but experienced engineer with a hot genius daughter, a young muscular physicist to fall in love with said daughter, lose in a misunderstanding and then ultimately win back . A weasely officer who gets killed but only after redeeming himself oh and the token black guy.
Ah and right at the end the politician who didn't want them to go puts a gun in his mouth /gets fired/ gets squashed by the only piece of NEO to make it through (depending on the rating and comedy value needed)
Or we could do something else.
Any NEO on approach is *clearly* stealing the valuable IP of Hollywood triumphs such as "Deep Impact" and "Armageddon".
It is piracy such as this that endangers the whole planet. So the only proper recourse is to send the MPAA lawyers to sue the inbound hazard into oblivion...
Vic.
If an NEO does look to be on a collision course the first thing that will happen is that Paramount and Dreamworks will instruct their lawyers to sue. Then there won't be a problem as the FBI will seize the lump of space rock because it breaches the copyright of Deep Impact.
See SOPA and PIPA could save the world.
What we need to do is capture one of the many NEO's that whizz past us on a regular basis and park it in orbit around the planet.
We fit it with chemical thrusters, and when a NEO comes along that does pose a threat, we fire our parked asteroid ( Or after it's parked in orbit, a better name for it would be Moon Unit.) at it. The collision will either knock it off course or annihilate it.
Put a huge solar parachute or sail on the damn thing. Put it on a hella huge tether placed there with long cables and let the solar wind blow it off course. Then if you have the capability to steer it just put it out of danger at least and hey even send it to the moon to crash there or some place else that would be "safe". At least something like that should prove to be easier to achieve, cheaper and more effective than nukes or a gravity tractor.
might be to land and secure a giant electromagnet to it. It would have to be damned big, though, since the electromagnetic force is tiny compared to the force due to gravity and mass. A hybrid solution combining the idea of magnetic propulsion and the solar sail concept might be to attach superconducting tethers (which should be nicely chilled in the vacuum of space) to the rock and have them extend out as straight as possible (easy if the rock has any rotational moment, but prone to snapping if it's rotating too fast). Perhaps the combination of interactions between the system and the solar wind, the system and the earth's magnetic field and the magnetic flux generated by spinning the conducting wires in the other fields might be enough to impart it with enough momentum to direct it off course? I don't know enough about magnetism, let alone about spinning superconducting wires to know whether it actually works like this.
I meant that to specifically refer to magnetic repulsion, as in "build a big enough electromagnet that will interact with the Earth's magnetic field and knock the thing off course". Not the fundamental force of attraction/repulsion between charged bodies. OK, I know at least that Maxwell's equations unify "electricity" and magnetism (and light), but what I was thinking of was whether an electromagnet (using a purely magnetic motive force) could deflect the thing enough when you take the relative size of the Earth and the attendant gravitational attraction between it and the asteroid. I meant that the electromagnet would probably have to be huge in order to overcome Earth's specific gravitational attraction, and not a statement about the relative size of forces in the abstract.
It would be quite interesting to see whether such a magnet-based solution would work, or whether building and powering a large enough one would even be possible.
As someone has mentioned, the first step has to be to improve the detection system which currently seems to be unable to spot rocks until they're hurtling past us (maybe they just listen for the 'whoosh' noise).
As a bonus benefit, we might also catch the alien ba*ds that have been dumping their waste CO2 in our atmosphere.
Why not just attach a giant flywheel to it, with a small electric motor to bring it up to speed. Then, you get the thing spinning fast enough, and it flies apart from the centrifugal force. Problem solved!
Or, if it doesn't fly apart, it'll be spinning so fast when it hits the atmosphere, it simply bounces off (probably kicking most of the atmosphere out the other direction, though). Again, problem solved!
Dave
P.S. As for nukes, would anyone trust the nuke on a Russian rocket to land where it was intended?!? ;-) I mean, the last time they shot for Mars, they hit Earth.
First you got to spot it.
Would suggest the money be better spent on designing a decent early warning system, using available technology, to give an advanced notice of more than 48 hours that the 10kt kinect object is going to hit.
reason for the focus, a 10kt hit may not directly wipe out the planet (only a city if they are underneath it), but a 10kt hit in the wrong geo-politic zone could trigger a NBC weapon response on the perceived attack of a neighbouring state (e.g. pakistan, india, iran, israel), especially during periods of hightened tension
If detected early on then attaching a solar sail to it would be the cheapest more effective option. If time is a factor then the rail-gun approach. The most cost effective way would be to watch the skies and take action the absolute soonest possible. Just the smallest nudge early on can avert catastrophe years later.
GIven the location of Hubble, etc there's nothing technically wrong with the idea. Velocity can be buit up again using solar power a long wire and some suitable pushing against that handy magnetic field which just happens to envelop the planet.
This technique is already in use on a small scale. Noone's tried it on anything as big as Hubble (there are some moves afoot to try and use it to keep ISS aloft)
It seems a lot of people favour the idea of simply blowing NEOs to bits with a nuke. This weeks near miss was something over 6 miles in diameter, assuming that it was solid rock it would take a pretty serious warhead to blow that to bits. If your plan is to divert it rather than blowing it to bits you still have problems.
You might think that if you hit it with a nuke in the right place you would divert it onto a safe course. Maybe you would, just so long as you didn't miss your spot and divert it onto a more dangerous course. But unless you know what the composition of the object is you don't know what's going to happen. You could blow loads of chunks off it and could end up with a whole load of radioactive rocks raining down on earth. The thing could split into two or more bigger chunks on unpredictable courses. There are all sorts of things that could go wrong with such gung ho approach.
However since this is unlikely to be a problem I don't see why anybody is serious considering diverting huge amounts of money at it when there's no money around anyway. Have these guys done a proper risk assesment on the possibility of NEO impact?
er ? 11 metres is closer
BBC
"The asteroid, estimated to be about 11m (36ft) in diameter, was first detected on Wednesday."
CBS
"A small asteroid the size of a city bus zoomed between Earth and the moon's orbit Friday (Jan. 25)"
I agree about the nuck though
"The thing could split into two or more bigger chunks on unpredictable courses. There are all sorts of things that could go wrong with such gung ho approach."
I've never heard of chunks broken off of something being bigger than the original thing.
That said, even a broken-up asteroid would be better than one big one. Increases the surface area, meaning friction gets more play on it, burning more of them up as they hit the atmosphere. Plus it scatters the impacts, making them more widespread but less severe: probably more survivable. It's kinda like getting pelted with 1kg of pebbles rather than banged on the noggin with a 1-kg rock.
whats with all the thumbs down, woulent have to wait 25 years for probes to reach the edge the solar system with historic technology, adust the power to change the speed of the projectile, the us navy railgun does 5300kms with access to its own reactor, a nasa or international orbital railgun wouldnt be aimed at a country