Could we stop an asteriod if we had to?

[Blizzard1]

I was browsing through the future articles in Wikipedia last night, mostly articles about future years, and mostly about science fiction set in those years. But there was one date which they had a real prediction for- March 16, 2880, the day when the asteroid 1950 DA will have a 1/300 chance of smashing into the Earth.

Assuming that NASA's calculations are correct (they may very well be flawed), the Earth will come very close to complete destruction in 875 years. Although we will most likely be able to neutralize this thing long before the 29th century, it could be ignored for several generations, giving our decendents in the 2800s a real space race.

Could we, if we had to, destroy or deflect and asteroid today if we had to? It would certainly take at least a couple of years to get everything together, and an even longer warning period, but I think we certainly could. It probably be more of a deflection move instead of a scene from Armageddon, but it could be done if we took the protential problem seriously.

[MrFrosty]

The science types would logically ask about the size of the hypothetical asteroid. Also, how much lead-in time is the world given?

[Loren Pechtel]

Without specifying the size, orbit and the lead time it's unanswerable.

Something like the rock that caused a scare last month would have been easy. It made numerous flybys before the projected impact date which means low delta-v requirements to intercept. Furthermore, it was more than two decades out--even in the worst case (if the original impact was dead center), nudging it a mere 1/3 inch per second would have been enough.

The same rock approaching from the outer solar system and first picked up a few weeks from impact (note: some close approaches have only been detected *AFTER* they missed--a short leadtime isn't out of the question by any means), there's no way we could have knocked it aside.

[Holly]

I'd have to say most likely not. It would be nice if we could but how would we do it? :confused:

[Loren Pechtel]

I'd have to say most likely not. It would be nice if we could but how would we do it? :confused:

For something like the recent scare, take a big h-bomb and put it on a rocket. Get it close and set it off. It's not going to be that big of a nudge but if you intercept sufficiently far out it doesn't take much.

The idea of using nukes to move things has been around since the 60's and has even undergone some testing. (here's (http://www.islandone.org/Propulsion/ProjectOrion.html) a writeup on it. I haven't read it but at a quick glance it seems ok.)

[vixstile]

Could we stop an asteroid if we had to?

Without any sort of qualification, that is impossible to answer.

Of course if we just noticed an asteroid that was going to hit us in a matter days/weeks there would be pretty much squat we could do about it.

But I would say if we were given a decent amount of time to prepare counter measures, we could easily prevent a hit.

[_Naturalist_]

If we really had to, then we could do it, I'm sure of it. A short while back there was some attention in the media about an asteroid that could potentially hit Earth in 2029 (turned out it wont) and I think that would be enough time for us to figure out how to deflect it.

[Amen-Moses]

I'm in agreement with everyone else here. Totally depends on how big, what it's made of and where it's coming from.

Comets and comet like asteroids (i.e loosely packed aggregates) are pretty difficult to shift without them breaking up and possibly making things even worse but could possibly be broken into small enough bits that you turn a certain world killer into a surviveable situation. Otoh a big solid asteroid would be almost impossible to shift with todays technology unless you had a huge lead in time (at least one orbit) in which to act and even then a close call could be just a devastating as a direct hit (i.e by affecting the Earth-Moon gravitational system sufficiently to screw up the Earths weather systems).

Small asteroids could be motoring around the solar system under the power of robotic mass drivers in a few decades from now if there was enough profit involved so not only can we shift them but we most probably will be. One neat plan I saw was to use smaller asteroids to break up or deflect the bigger ones, i.e if we mapped out all the little Earth crossers and planted mass drivers on them connected to a huge AI system it is theoretically possible to play billiards on a cosmic scale. Unfortunately it is also highly possible that someone (or something, Skynet anyone ;)) could use such a system as a weapon of almost unlimited lethality.

Amen-Moses

[Loren Pechtel]

Comets and comet like asteroids (i.e loosely packed aggregates) are pretty difficult to shift without them breaking up and possibly making things even worse but could possibly be broken into small enough bits that you turn a certain world killer into a surviveable situation. Otoh a big solid asteroid would be almost impossible to shift with todays technology unless you had a huge lead in time (at least one orbit) in which to act and even then a close call could be just a devastating as a direct hit (i.e by affecting the Earth-Moon gravitational system sufficiently to screw up the Earths weather systems).

Blowing them to rubble doesn't help unless the intercept is far out. At close range we would fare better not shooting, the rubble would be more devastating than the single object hitting.

A solid object would be a lot easier to shift as you don't need to worry about it going to pieces when a nuke pops off nearby.

I do think that anything we can deflect will have at least a one-orbit leadtime. If we detect it on it's impact approach it's going to be too late to do anything--we'll probably only pick it up days out if that. (Some near misses have been picked up *AFTER* their close approach.)

Small asteroids could be motoring around the solar system under the power of robotic mass drivers in a few decades from now if there was enough profit involved so not only can we shift them but we most probably will be. One neat plan I saw was to use smaller asteroids to break up or deflect the bigger ones, i.e if we mapped out all the little Earth crossers and planted mass drivers on them connected to a huge AI system it is theoretically possible to play billiards on a cosmic scale. Unfortunately it is also highly possible that someone (or something, Skynet anyone ;)) could use such a system as a weapon of almost unlimited lethality.

Someday we are probably going to be shoving asteroids around. I think the security precautions will have to be considerable. I suspect we will see something like some very large ordinance mounted on the asteroid and with anti-tamper provisions. It also has a tracking computer and will blow the thing to bits if it's trajectory heads too close to Earth.

[Shadowy Man]

The main thing to keep in mind is that all of this is highly theoretical. We have never attempted to move a comet or asteroid, nor have we even developed any plans to do so.

I think that if moving the object is a viable option to saving humanity, then we shouldn't wait until the last minute to make sure it would work. It would behoove us as a species to build some spacecraft and go out there and attempt to move a comet or asteroid.

[BioBeing]

(Some near misses have been picked up *AFTER* their close approach.)
Why is it that we do not see these things? Do we monitor space for them? Are they too fast, or too small? Are any of these that we have missed of a big enough size to do any damage? Enquiring minds want to know!

[Hyndis]

Why is it that we do not see these things? Do we monitor space for them? Are they too fast, or too small? Are any of these that we have missed of a big enough size to do any damage? Enquiring minds want to know!

The budget ain't there to monitor these threats. :rolleyes:

Its the guys with telescopes out in their backyards that tend to find a lot of these NEO's. Not NASA or NORAD.

[Amen-Moses]

Why is it that we do not see these things? Do we monitor space for them? Are they too fast, or too small? Are any of these that we have missed of a big enough size to do any damage? Enquiring minds want to know!

Basically it is a similar problem to the one pilots have, if something is on a colision course with you it does not appear to be moving relative to your pov so the only way of spotting them is if they pass between you and another object, unfortunately trying to pick out an apparently non-moving rock the size of Texas against a backdrop of trillions of stars is a far harder task than finding a needle in a haystack until it gets pretty close.

Those that travel across our field of view are easier to spot because they will invariably cross in front of many many stars one after the other so a sequence of "dimming" stars gives away their position.

Something the size of a house on a direct collision course will usually reach the atmosphere before we spot it.

Amen-Moses

[Ad Astra]

Why is it that we do not see these things?
If I recall correctly, the reason many close-calls are missed is because some approach from the direction of the sun, making it difficult to detect them until after they've passed.

[Schneibster]

Without knowing the time to stop it, and the size of the asteroid, this question is not answerable.

If we have time, we can stop anything. If its not too big, then we can stop it in limited time. Most likely a big one will give us a lot of warning, but you never know.

[Amen-Moses]

If I recall correctly, the reason many close-calls are missed is because some approach from the direction of the sun, making it difficult to detect them until after they've passed.

As I said above if they are on a direct collision course then it matters little which direction they come from they will be very hard to detect but if they cross in front of the sun or venus we would spot them pretty damn quick as each of those astral bodies are studied intensely.

The good thing as far as we are concerned is that in order to swing around the sun and hit the earth on the way out they would have to pass us on the way in to the sun in the first place so they would most likely show up quite early and give us a good year at least of notice. The problem then is that we have no real way at present of catching up to the damn thing before it orbits around behind the sun and comes back to do the dirty on us.

The really big threat is the huge comets that may be perturbed out in the oort cloud and come plunging in on a direct collision trajectory, they are impossible to deflect (well without a starship enterprise they are) and would give very little in the way of notice as they would not be detected until they pass close to Mars which is about a month away at the speed they would be travelling by then.

Actually the more I think about it the more I'm deflecting to the "we would be fucked anyhow" camp, at present we just don't have the technology to make a dent in a really big bugger on a direct collision trajectory no matter how early we see it or where it comes from.

Amen-Moses

[Autonemesis]

Without specifying the size, orbit and the lead time it's unanswerable.

For 1950 DA, here are the stats:

Size: 1.1km
Orbit: known to highest precision current technology can provide (radar)
Lead time: 875 years (close approach March 16, 2880)
Risk: between 0 and 0.33% above background risk as compared to all other objects passing near Earth in the next 875 years.

1950 DA is the only known asteroid whose collision risk may be above the background risk. It is interesting to note that if the rotational axis conforms to one possible solution based on current radar data, the risk becomes zero, while the 2nd possible solution gives a risk of 0 to 0.33% above background.

Source: http://neo.jpl.nasa.gov/1950da/

With enough notice, simply sprinkling one hemisphere of an asteroid with a reflective material - talcum powder, for instance - could alter the trajectory of a collider to that of a near-miss. So given enough time, we definitely have the technology now to deflect an asteroid. The difficulty is recognizing the ones we need to sprinkle with talc, and the ones we should leave alone.

[Hyndis]

With enough notice, simply sprinkling one hemisphere of an asteroid with a reflective material - talcum powder, for instance - could alter the trajectory of a collider to that of a near-miss. So given enough time, we definitely have the technology now to deflect an asteroid. The difficulty is recognizing the ones we need to sprinkle with talc, and the ones we should leave alone.

A "near-miss" will still cause a heck of a lot of havoc on the ground. ;)

Unless maybe you're hoping that it'll skip off of the atmosphere...

[Loren Pechtel]

Why is it that we do not see these things? Do we monitor space for them? Are they too fast, or too small? Are any of these that we have missed of a big enough size to do any damage? Enquiring minds want to know!

We have only recently begun to monitor space for them and we don't have them all cataloged yet--and we will never be sure as orbits sometimes get jostled. We can't pick them out unless they are reasonably close to Earth, also. They are tiny, the sky is vast. Doing sky surveys with the big scopes is out of the question, they look at too little. The sky surveys are done with rather modest scopes because they can see more.

Beyond this you need a minimum of three sightings to get anything resembling an orbit and note that it took well over a hundered to rule out the recent scare.

Here's (http://neo.jpl.nasa.gov/risk/2004mn4.html) the data on that rock that had the astronomers worried. Note that it's a magnitude 19.4 object. That's *DIM*. A bit of searching with google says you'll need more than 4' of telescope (and that's a *LOT* of telescope!) to make it barely visible to the naked eye. I didn't find anything saying what the limit is for cameras.

I do think it should be funded to a much greater degree than it is currently. Every estimate I've seen of the risk posed by asteroids makes the risk well above that of commercial aviation. However, the odds of anyone dying in a given year are quite low--it's just a big rock could cause so much damage. (Consider: Tunguska. No human deaths were reported, it only blew up a piece of uninhabited forest. Had it fallen 7 hours earlier it would have caused a lot of deaths and changed the course of human history--by blowing Leningrad off the map. Note that Tunguska was only a bit over 1% of the energy of 2004mn4.)

[Loren Pechtel]

For 1950 DA, here are the stats:

Size: 1.1km
Orbit: known to highest precision current technology can provide (radar)
Lead time: 875 years (close approach March 16, 2880)
Risk: between 0 and 0.33% above background risk as compared to all other objects passing near Earth in the next 875 years.

1950 DA is the only known asteroid whose collision risk may be above the background risk. It is interesting to note that if the rotational axis conforms to one possible solution based on current radar data, the risk becomes zero, while the 2nd possible solution gives a risk of 0 to 0.33% above background.

Source: http://neo.jpl.nasa.gov/1950da/

With enough notice, simply sprinkling one hemisphere of an asteroid with a reflective material - talcum powder, for instance - could alter the trajectory of a collider to that of a near-miss. So given enough time, we definitely have the technology now to deflect an asteroid. The difficulty is recognizing the ones we need to sprinkle with talc, and the ones we should leave alone.

With an 875 year leadtime I'm sure we could knock it aside. The maximum required deflection is only 1/2 inch per minute.

[Shadowy Man]

1950 DA is the only known asteroid whose collision risk may be above the background risk.

It's all the ones we don't know about we need to worry about!

[American Humanist]

Assuming a typical asteroid /comet of say 10km (6mi) or about the size of the one that got the dinosaurs:
We'd need at least a few months to get a mission together (planning, building, getting it to the object, etc.); but with currently available technolgy (that is technology we could deploy imediately), we would probibly have to resort to a stand-off nuclear detonation. In a stand-off detonation the warhead would be detonated a few hundred meters to a few kilometers from the objects surface and the resulting neutron flux would vaporize surface material leading to a small thurt way from the explosion site. There of course would be no shockwave as there is on Earth in our thick atmosphere. Given that a stand-off detonation wouldn't change the object's orbit by much, the sooner it was preformed the better the chance of averting an impact. The closer to impact it got the larger a force would be needed to make the object miss. If we only had a few weeks we'd be screwed.

The way things are going now it looks as if in two centuries time we'll be a truely spacefaring civilization and fully capable of deflecting an asteroid or comet given a few months warning.

In any case the key to sucess will always be early detection of the threat since the more time you have the smaller a force you have to apply to the object.

[diGriz]

I think that if moving the object is a viable option to saving humanity, then we shouldn't wait until the last minute to make sure it would work. It would behoove us as a species to build some spacecraft and go out there and attempt to move a comet or asteroid.

Humans have a long history of ignoring potential and even current problems until the last minute.

[Answerer]

The way things are going now it looks as if in two centuries time we'll be a truely spacefaring civilization and fully capable of deflecting an asteroid or comet given a few months warning.



You don't have to deflect an asteroid. Earth, itself, is a coward and it move (revolved) freaking fast. So, all the nations on the Earth had to do is to slow down the speed of the asteroid (through bombardment or what) enough for Earth to move out of its way. Thats the most practical method, much more practical than those showed in the movies.

[chapka]

As I understand it, we generally don't see these things now until they're a few days away at most, and afterwards at worst.

If we knew it was going to hit us, we have no way of destroying or deflecting it accurately.

Even if we had explosives powerful enough, we would have no way of delivering them, especially on short notice. Existing missiles don't work that way.

In short, if something is on track to hit us in the next few years, there's probably fuck-all we can do about it.

However, I wouldn't worry that much. A supervolcano eruption is probably more likely, and could be just as devestating. Anyone who lives in the United States should probably be worrying more about Yosemite than about asteroids.

[Clivedurdle]

New Scientist has an excellent editorial (8 January) about the Tsunami and a fascinating article about diamonds.

The Diavik Diamond mine in Northern Canada is making $400 million dollars per annum. Would that not help pay for a fully comprehensive planetary and space risk assessment and reaction system, covering everything - asteroids, volcanoes, earthquakes, global warming etc?

Should not the oil, gold, diamond and mineral companies be paying for this world wide excellent database and surveys of the entire planet and solar system?

The multinationals cannot do their present work without the expertise of geologists. I recommend all geologists stop working individually for private companies and only work as associate consultants of an international geo physical organisation mandated to take a global perspective and paid for by the oil gold diamond and mineral companies.

We might then plan properly for whatever types of disaster we can foresee, and resource properly independent academic and pro active research, disaster prevention and disaster recovery systems.

[Loren Pechtel]

You don't have to deflect an asteroid. Earth, itself, is a coward and it move (revolved) freaking fast. So, all the nations on the Earth had to do is to slow down the speed of the asteroid (through bombardment or what) enough for Earth to move out of its way. Thats the most practical method, much more practical than those showed in the movies.

I would think the delta-v requirements for a deflection would be the same as for altering it's speed.

[Dhaeron]

I would think the delta-v requirements for a deflection would be the same as for altering it's speed.
Hm, that may depend. If it is deflected to a side, the added v must be high enough to move it (let's assume it was straight on target) a bit more than than one r of the earth to the side until it hits. If you slow it down, the distance stays the same, however you need to buy enough time for the earth to get out of the way. At the earth's speed, a couple of seconds might be enough, while moving an asteroid should be much slower. However, this only works if it isn't in the earth's path. :Cheeky:

[Ulrich]

New Scientist has an excellent editorial (8 January) about the Tsunami and a fascinating article about diamonds.

The Diavik Diamond mine in Northern Canada is making $400 million dollars per annum. Would that not help pay for a fully comprehensive planetary and space risk assessment and reaction system, covering everything - asteroids, volcanoes, earthquakes, global warming etc?

That's the spirit, blame Canada! They're not even a real Country anyway. :Cheeky:

Should not the oil, gold, diamond and mineral companies be paying for this world wide excellent database and surveys of the entire planet and solar system?

If that is our only option, we are definately screwed.

The multinationals cannot do their present work without the expertise of geologists. I recommend all geologists stop working individually for private companies and only work as associate consultants of an international geo physical organisation mandated to take a global perspective and paid for by the oil gold diamond and mineral companies.

While I think you may find more altruism in the ranks of geologists than those of Oil Barons (where you will likely find exactly none), if we are reliant upon this option, we are hosed.

We might then plan properly for whatever types of disaster we can foresee, and resource properly independent academic and pro active research, disaster prevention and disaster recovery systems.

Unfortunately those controlling the oil, gold, and diamond industries cannot see past the vast vaults of cash surrounding them, and have enough control in world government to see to it that nothing like this will ever come to pass.

[flippant]

That's the spirit, blame Canada! They're not even a real Country anyway. :Cheeky:


Yeah. It's Canada! :wave: Their fault their problem. I also have heard they have more webbed feet births per capita. :rolling: Darned mutants!

On that note.....If we (theoretically) cared about science and the progress of our rapid extinction we could (theoretically) do something about a lot of things...but "we" don't and "we" don't think about things that really matter. We "care". We really do. But don't quote "me" on that.


You guessed it! I'm feelin' a little silly today. :Cheeky:

[Loren Pechtel]

Hm, that may depend. If it is deflected to a side, the added v must be high enough to move it (let's assume it was straight on target) a bit more than than one r of the earth to the side until it hits. If you slow it down, the distance stays the same, however you need to buy enough time for the earth to get out of the way. At the earth's speed, a couple of seconds might be enough, while moving an asteroid should be much slower. However, this only works if it isn't in the earth's path. :Cheeky:

I see your point. You're only half right, though.

If the object is approaching side-on, then speed/slowing is likely easier. If it's pretty much in our orbit then speeding/slowing is of little value.

The biggest threat is from the NEO's that are basically in our orbit. (A rogue object will pass us once. The NEO's pass us again and again.)

[Schneibster]

We seemed in mid-2004 to be trending downward in detections of new threats, but that has changed in the intervening time. this (http://neo.jpl.nasa.gov/stats/) is worth studying.

[Clivedurdle]

My apologies, I was not attacking our beloved Dominion - that does mean the UK still dominates Canada doesn't it - but the owners of the mine - RTZ and their ilk.

Maybe scientists have more power than they realise if they renegotiate their contracts... and as I remember there are concepts of corporate social and environmental responsibility! What did that twelth century monk say - from each according to their ability to each according to their need.

[g-21-lto]

Could we, if we had to, destroy or deflect and asteroid today if we had to?
Only if we had Bruce Willis and Ben Affleck on the case.

Deflecting or destroying an incoming asteroid doesn't seem very likely. Besides the problems in calculating just the right place and time to deflect it, could we have a good enough estimate of its mass to know the amount of force needed?

[jayh]

With an 875 year leadtime I'm sure we could knock it aside. The maximum required deflection is only 1/2 inch per minute.

Herein lies the rub.

Most potential impacting bodies have a window a couple of years out of just a few minutes (that is 10 minutes early or late in calculation of the precise timing of arrival crossing earth's orbit two or more years from now is the difference between a hit and a miss). Therefore since the positions and orbits of most small bodies aren't known that accurately (and all their interactions with other orbiting bodies may make such calculations impossible), nudging one can just as easily cause an impact as avoid one. Thousands of substantial items cross the earth's orbit, it becomes an issue only when it crosses the orbit at the exact moment the earth does.

Reliably predicting and handling these is beyond current technology.

[Clivedurdle]

If the lead time is enough. there is no need to nudge it out of the way, it could just as easily be taken apart or dismantled.

[jayh]

If the lead time is enough. there is no need to nudge it out of the way, it could just as easily be taken apart or dismantled.

The problem is, there is no way to know far enough ahead which one of the thousands to take apart.

[Clivedurdle]

Then RTZ Universal mines them all, starting with those with a reasonable probability!

[baron greenback]

I think the social problems surrounding the issue put the scientific problems on the back burner in this case. The reason being, simply put, is that not all the current technology is available and readily disposable. It's one thing to say that yes, an ICBM with x megatonnage could move asteroid y out of the way. That's a question five minutes and a calculator can answer.

The problem is, even if response time is known, we don't (or aren't supposed to, and therefore don't without equally lengthy delays caused by secrecy) have any nuclear devices or orbal lazers in place. The threat caused by an orbital device capable of knocking an asteroid out of earth's path is obvious to anyone who thinks half a minute about it; early ICBM detection systems wouldn't work on something unpropelled and simply dropped onto a country, not to mention the risks posited by orbital lazers.

It would be great if we had some sort of solution that would allow us to have a NEO deterrent system in place while absolutely preventing any use on any terrestial power (or on earth period). Encryption and information technology could hypothetically prevent this sort of thing, but of course questions remain about malfunctions and hackers. Sadly, this is the sort of problem that is the realm of science fiction authors, and I'd be surprised if any serious thought outside of academia has been devoted to the problem at all. It's the sort of thing where hastily made (and often bad) policy is put in place to solve a crisis and then adhered to with adamant beauracratic ritualism, simply because people are too lazy to plan ahead.

Which, of course, is why privatized space travel is so important >:)

[Loren Pechtel]

There's no reason for asteroid interceptors to be stored in orbit until we reach the point that they have the power to deflect something at close range. As it stands now, the additional time required for the warhead to be lifted is irrelevant--if a few days are going to make the difference it's too close anyway. When there's enough people living up there to maintain the rockets then we will see space-based interceptors. Until then, they'll fly from the ground.

[baron greenback]

There's no reason for asteroid interceptors to be stored in orbit until we reach the point that they have the power to deflect something at close range. As it stands now, the additional time required for the warhead to be lifted is irrelevant--if a few days are going to make the difference it's too close anyway. When there's enough people living up there to maintain the rockets then we will see space-based interceptors. Until then, they'll fly from the ground.
Well... I hate to say it, but you're absolutely right.

I wasn't really thinking about the rockets and/or lazers needing continous human maintenance, which of course would place them in a different category than traditional communications satellites and other current orbital technology.

Thinking a little about it, though, the whole purpose to having an orbital Near Earth Object defense would be increased reaction time. And, given that we've already seen how much better orbital telescopes are at seeing things than earthbound ones, a better idea would be an orbital detection system. An orbital grid sending data down to us would also provide a wealth of information about our solar system anyway; as is, our technology in this area can be described best with the words "ametuer" and "volunteer". Which is to say that, were a NEO to be detected, it would more likely be detected by a hobbyist than a proffesional astronomer. It would also neatly avoid any paranoia; we already have communications satellites everyone knows about that do a far more efficient job of recording what's on earth than a NEO detection system would.

Not, of course, that anyone would fund anything like this; this falls neatly into the "spending money on space instead of on world hunger/peace/puppies" trap.

[Clivedurdle]

adamant bureaucratic ritualism

Love that phrase!

I wonder if we have a window of opportunity to establish - apologies for quoting myself! -

a fully comprehensive planetary and space risk assessment and reaction system, covering everything - asteroids, volcanoes, earthquakes, global warming etc?