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Nukes Not the Best Way To Stop Asteroids, Says Apollo Astronaut
MajorTom writes "Right now, we are not tracking many of the asteroids that could destroy earth. But within the next decade, new telescopes will make that possible, and leave us with the tough decision of what to do about objects with an alarming chance of hitting our planet. Last year, NASA said that the best option is to nuke them. This week, Apollo astronaut Rusty Schweickart, explained that there are far better options, and he has started an organization to prove that they can work."
Then what does he propose that we nuke? Each other? The whales? Martians?
If Edgar Mitchell's involved, then we know for sure that nukes are the best option!
It's the only way to make sure.
To save you all the horror and pain of reading TFA (since TFS doesn't state), Schweickart is suggesting we either push or pull them away with unmanned spacecraft.
If we can detect it in time then a push from behind/side might have time to help enough. Seems to me a nuke would be more of a last minute Oh Crap choice.
Move it into orbit and mine it.
...it's the only way to be sure...
oh wait.
He's saying pushing or pulling an asteroid is better than hitting it with a nuclear weapon, but the interesting thing is that he's claiming NASA issued its pro-nuclear statement last year in response to political pressure to put nuclear weapons in space.
---
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Please let one of the options be to send Ben Affleck into space. He has experience.
The best option by far would be to try to land Harrison Ford, and Aerosmith on it.
Find those advanced aliens that the other Apollo astronaut says are in our midst, and arrange for technology transfer briefings on asteroid redirection.
But what about using nukes as some sort of "propulsion" system (as in the Project Orion), so they can change the direction of the asteroid? Wont be something for the last minute, but, could work?
Why couldn't we just use nukes to redirect them? Detonate one of them near the asteroid, push it off course, and keep doing this until a desired trajectory is met that will not cause it to collide with Earth or the Moon. Its kind of like pushing a basketball mid-flight, you wouldn't be stopping the full force of the ball as much as just redirecting the current energy with some other force. It would require that we have early knowledge but still could work.
And of course anything that breaks off could be nuked also into smaller pieces till they are no threat. Of course we would have to be constantly scanning for these pieces but if a ball of death is heading for us I would assume all telescopes would be looking at it anyway.
First an Apollo Astronaut says that the government has covered up Alien contact, now this!?
I would think, if the "safety of the Earth/mankind" is at risk .... Shouldn't they be putting their theory to work? I'd want to make sure that a nuke CAN divert the asteroid in practice than reading about an academic debate or reading that NASA administrators/management reiterate probably incorrectly that their plan of action is the right way (as always and as government organizations always do).
Shouldn't there be an International Body finding a solution. The US isn't the only country with nukes, the right group of scientists, etc. etc. that can find a possible solution to this problem.
The main problem with nukes is that criminals will be released from the Phantom Zone if a nuclear weapon goes off in space.
Write your own Choose Your Own Adventure. http://www.freegameengines.org/gamebook-engine/
so, let me see if I got this right:
you would have a small triangular ship. Maybe two or three extras "just in case".
we could control it remotely. A rotational control and a forward thruster should suffice.
Then we could "fire" small nukes at the object. That would change their trajectory and break them into smaller pieces.
I think it sounds like a brilliant idea, but where would we be able to find someone who could operate such a machine?
-- Sig under construction...
Nukes have been a popular options because:
1. We have them.
2. They have a high ISP (a measure of efficiency) when used as propulsion against a large object. Paradoxically, the ISP for Orion-style nuke propulsion increases with the size/mass of the object.
3. They're much more portable compared to most other types of methods.
Schweikart has identified the REALLY valuable truth, that we need to improve our detection method. We also need to develop deep space capability because the further out we can intercept them, the less energy is needed to perform the deflection. Lower energy can also mean less danger of fracturing the mass.
...That the best solution is to wait until it gets so close that "I can see my house" and then open up a Hyperspace Window to take the thing to the other side of the planet.
Its what Macgyver would do.
The simply answer is that the physics are already known, and it all depends on how far in the future the impact is before we detect it. Given a century just about anything would work. Given less than a year, almost nothing would.
Given a couple decades, yes, there are a number of non-nuclear options. A nice high impulse drive, perhaps a number of them, set into the surface of the asteroid. They thrust in the proper direction over a long period of time, and we end up being able to put the asteroid pretty much where ever we want it.
In a shorter time frame or larger asteroid, nukes might end up being the best choice. Of course, for best propulsion, like in the horrible movie, burying it might be the best option - that allows part of the mass of the asteroid to be used to propel the asteroid in the opposite direction. The ejecta, even though some is almost guaranteed to hit the earth, is okay because it'll overwhelmingly burn up in the atmosphere.
I don't read AC A human right
... asteroids vs duke nukem :D
Just wait until the last possible moment,open a hyperspace window and let the astroid fly "through" earth.
Problem solved.
The probability is vanishingly small we'll get crunchified and the likelihood of any bureaucratic solution even working is also damn low. So let's just accept that there's a nonzero probability that we'll all get wiped out. Worst case we all die someday anyway.
We still have that wrecked Goa'uld starship's hyperdrive.
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Trying to use nukes to deflect the asteroid seems like the more difficult solution to me. The asteroid will be far away and moving fast. Earth is close and (relative to us) not moving at all!
Clearly the more practical way to avoid a collision is to use the nukes to deflect Earth out of the path of the asteroid.
paintball
Not exactly what TFA is talking about, but I dislike how the very real threat of asteroids is trivialized in the public mind. Every time astronomers discover a remotely threatening asteroid, anything that hits 1 on Torino scale, journalists warn of a dangerous collision that could wipe out a continent, yadda yadda, while further observation of the asteroid over the next weeks shows that there's no chance of collision. So the public hears these stories about asteroids at least once a year and many thus think that it's a bogus threat because, oh, whenever journalists warn of a possible collision it turns out to be a non-threat, so it will never be a threat, right?
Makes me wish that journalists would just shut up about any objects lower than 3 on the Torino Scale.
If you identify objects on collision course in time, only a very minor adjustment in its trajectory will result in it missing by a very wide (and safe) margin.
"Waste not one watt!" - CZ
If we were to use a nuclear weapon against an asteroid, there would be a few problems-
1.The asteroid might break apart into several smaller pieces, possibly making the problem worse
2.The size of the nuclear warhead would have to be enormous in order to blast a huge rock out of the way. Blowing up a huge nuclear warhead would create alot of radiation, and some of it will come back down to Earth.
I think the best way to deal with an asteroid is to send a rocket to the asteroid, land on the rock and use that rocket to push the asteroid out of the way. It would be a real pain, but we have landed spacecraft on an asteroid before.
And if that fails... NUKE IT!
Well, duh! Nukes are second best, only to be used if Chuck Norris is unavailable.
So why does anyone get surprised when NASA changes its tune in accordance with political whim, be that on the use of nukes or on global warming?
Engineering is the art of compromise.
This has been discussed over and over again, now we attach some old astronaut to it and suddenly people should care again. NASA has been working on other means to gently nudge asteroids seen coming towards Earth when they are very far away. People are just afraid of nuclear fall out from the smaller bits of the asteroid after the explosion, but odds are the pieces would burn up in our atmosphere. It's ridiculous that this is still being talked about. I've seen Armageddon and Deep Impact, we're gonna send John Glenn into space with some young cocky people and some mining team - they'll save us all and get high schools named after them.
"Why are hemorrhoids called hemorrhoids and asteroids called asteroids? Wouldn't it make more sense if it was the other way around? But if that was true, then a proctologist would be an astronaut." - Robert Schimmel
In that context, nukes do seem like a rather extreme solution.
Momentarily, the need for the construction of new light will no longer exist.
Instead of exploding the nuke, a better way would be to harness the energy from a controlled nuclear reaction to gently push the asteroid. However, we must first locate the asteroids before we think of ways of dealing with it.
If a 1 MT (4.184x10^15 J see http://en.wikipedia.org/wiki/Megaton) nuke explodes on the surface of a 4 million ton asteroid, and only 1% of the energy released is converted to motion, then the change in velocity will be:
4.184x10^15 J * 0.01 / 4x10^9 kg * 1 (kg*m/s)/J = ~ 1x10^4 m/s
Sounds like a big enough delta v to move it (or what's left of it) away from us.
Didn't anyone ever watch Star Trek? This is such a simple problem. Just change the gravitational constant of the universe, thereby altering the mass of the object and making it easy to move. Oww! Where is that doctor?!
Sorry I couldn't resist.
The way the world is going on, maybe nukes will be the way to avoid any future asteroid kills humans here, or maybe just the few surviving ones.
Nukes are big lumps of dV, ion engines are small streams of dV. There's a range of options in between. Small, continuous thrust over time can equal large, impulse thrust over a few seconds.
It all depends on when you can identify and engage the celestial body under discussion. The less warning, the shorter the time you have to apply the necessary dV for the effect you want. The effect you want is a change in velocity vector, and how you need to change the moving body to go faster | slower | different direction depends entirely on the orbital mechanics of the individual event. Work the problem when you find out about it.
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The problem with landing on the asteroid and setting up a rocket motor to push it into a safe trajectory is that asteroids tend to be rotating. Most of the time you will be pushing it the wrong way. (Of course you could turn the moter on only when it would be pointing the right way, but that is going to take longer.) The trick is to start early enough, so we need much better detection and orbit analysis.
The phrase "political pressure to put nuclear weapons in space" doesn't really reflect what they're trying to do. While there is some pressure for placing a military capability in orbit, most parties see such a move as too politically sensitive and destabilizing.
There is however a very powerful lobby that seeks government dollars for research, development and production of nuclear weapons, as their income almost ground to a halt in recent years. Deflecting asteroids now offers an excuse for getting those tax dollars flowing into their pockets again.
What's more, nuclear weapons capable of worrying an asteroid would have to be HUGE, which also means costly and hence very profitable. There is no precedent for making such enormous nuclear weapons, which means that umpteen billions will be (justifiably) requested for research in this area.
So, the pressure isn't really to put "weapons in space" as such, but to turn the paltry funding that nuclear weapons research currently gets into a torrent.
No offense to WK2; your post was clever and I actually laughed out loud, but "Insightful" instead of "Funny"?. I'm shocked SHOCKED that there are moderators here who have no clue what they're doing.
Jesus. Christ. This is the second mis-modded humorous post. Some idiot in this thread has no idea what the "Funny" tag is for. Looks like Edgar Mitchell's aliens have Slashdot accounts.
we are not tracking many of the asteroids that could destroy earth
Is that for a technical reason or is it that because there are precisely zero asteroids that could destroy the Earth? Severely damage yes, but destroy the Earth? Not likely since we believe a Mars sized object has already hit us and we are still here (by us and we I mean the Earth).
That was a rhetorical question by the way. So please don't reply and tell me that an object doesn't have to destroy the Earth in order to cause life on Earth to suffer. I'm aware of that.
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Has anybody thought about trying diplomacy? I mean we really don't know what an asteroid would want, and the reason for their hostility. I think we should try more peaceful means first.
So, should we tag this "whatcouldhavepossiblygonewrong"?
Find a way to put the earth in to hyperspace for a short time to skip over it. Like they did in star gate sg1
Anyone want to buy my Annihilatrix?
Here is an interview with Dr Stanley Love explaining one method to move an asteroid without breaking it.
http://www.cbc.ca/quirks/archives/05-06/nov12.html
Scroll down to 'Space Tug' and have a listen for about 8 minutes.
Wouldn't it make sense to try it as an experiment to gather hard data on how different types of asteroid react and as an excercise in examining the logistical problems and actual effect from a practical perspective?
It may make sense to have a gun, but if you don't know *which* gun to use...
My ism, it's full of beliefs.
SG-1 did it the other way around, they put the asteroid into hyperspace for a few seconds so it would skip over the earth.
Unless you're thinking of a late-series episode where they put an Alternate earth out of phase so the Orii couldn't find or attack it.
Moving the asteroid would probably be more favorable, as you wouldn't have to worry about jumping the earth too far as screwing with it's orbit.
Making it miss is a matter of nudging its orbit just enough that it doesn't intersect Earth any more. Capturing it requires slowing it down all the way to Earth-orbit speed. In space, just because something goes nearby doesn't mean it's easy to catch.
After all, they already had asteroid-blasting spaceships in the late 70's.
Is Professor Farnsworth born yet?
Nukes are the best for everything on Slashdot.
- Just trying to survive until the nanobots make me immortal -
You honestly believe that the flight time for an icbm allows the opportunity for the target to evacuate an area? fuel up lots of bombers? launch a counter strike?
With icbms there is no need for nukes in orbit to attack land targets. It is a totally pointless exercise *and* it leaves your nukes sitting around in orbit subject to damage from debris, jamming, capture, or attack from anti-sats or land based energy weapons.
Ridiculous.
In this video astrophysicist Neil DeGrasse Tyson describes an alternative solution: :).
http://youtube.com/watch?v=1-ReuLZ2quc
Worth watching, i swear
There are no asteroids big enough to destroy the Earth. There may be asteroids big enough on a future collision course that may cause a mass extinction. There are asteroids big enough on a collision course that will wipe out human civilization if not the human species within the next few hundred thousand years.
Of course, I think humanity has made tremendous inroads into setting it self up to destroy itself and could very well do so without a Toba like eruption or a major asteroid strike this century.
"You'll get nothing, and you'll like it!"
I say we go with the Homer Simpson theory. When the asteroid enters our atmosphere, air resistance will wear it away until it is the size of a chiuaua's head.
No worries!
I'm in to sadism, bestiality and necrophilia. Am I flogging a dead horse?
We'd just need to put Jerry Bruckheimer on it. The asteroid will suck itself into oblivion.
Wiki, Asteroid Deflection
NYT Study suggests mirrors best
NASA has non-nuke plans
Using a 300Kg impactor
Seems the consensus is that nukes would only be used if we discovered the asteroid too late for other methods to be effective.
Anarchists never rule
Toynbee Tiles.
Help stamp out iliturcy.
Apollo astronauts don't really have a good track record for being believable.
The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.
Little Boy at roughly 14 Kilotons was less than a gram of energy actually. Energy is really light. A TON of it would be quite a lot.
Yeah, pedantic. I know.
Help stamp out iliturcy.
Weapons effects are extremely interesting and useful. The first effect to know about is that stuff survives amazingly close to a nuclear explosion. The second effect is that you can "tune" a fission bomb to direct its energy output largely in one direction. (Don't jump on me, this is in the open literature now.) Which gives a different method of dealing with asteroids; a series of powerful, but not shattering, plasma "slaps" to change its orbit.
Send a spacecraft armed with lots of quite small fission weapons that are set up to direct their weapons effects mostly in one direction and with a very basic, robust guidance system. Each one needs to get tossed out, line up with the asteroid, trigger, and "slap" it with high-speed plasma. Enough "slaps" change its orbital characteristics. You don't try to shatter it.
Each fission weapon looks like this: Wrap up a small (5 kt?) fission core with something like polyethylene or anything that absorbs prompt soft X-rays. Anything that has mass. The onboard computer works with guidance (my guess would be aims for a laser point on the asteroid, but who knows), the guidance just lines it up properly with the asteroid, and triggers the fission.
Position it so that when it goes off, the plasma of the polyethylene (and the former physics package, etc), moving around 2.5 million miles per hour, strikes the asteroid. You don't try to break the asteroid up -- far from it. You go for a series of "slaps" with very hot material. As the physics formula says, Mass times Velocity Squared -- and here you have all kinds of velocity.
As Lew Allen proved, with his famous tests with steel spheres just a few feet from ground-zero of a nuclear test survive just fine, and they are accelerated quite briskly. This was one basis of Project Orion later on.
It would be quite interesting to model this against some asteroid sizes and get an idea of what would be required to change the trajectory. We certainly have enough plutonium cores laying around.
Just an interesting thought.
Thanks,
Dave Small
Why don't we just send up a bunch of Jehovah's Witnesses with pamphlets? I have seen even the biggest, strongest men hide behind the sofa when just one of them is at the door; it shouldn't take more than, say, ten to make an average sized asteroid go away.
Er, maybe I just read "Rings of Ice" at a too impressionable age.
Never mind.
The best way to stop an asteroid is to crash your planet into it. On the other hand, if you want to deflect it, nukes might be a way to go. Though I like the idea of using mirrors better.
The world you experience is only a close approximation of reality.
I'd fly a warp capable starship (ent - D) to intercept the asteroid, then stretch the warp bubble generated from the engaged warp engines, around the asteroid so it will 'weigh' less. Then, use a tractor beam to shove it out of the way.
Mimes I tell you, Mimes!!!
E = 1/2 mv^2
v = (2 * E / m)^0.5
That gives you a deltav of about 141 m/s.
Converting 1% of the nuke's energy might also be a pretty big if. A nuke produces lots of x-ray radiation... it takes an atmosphere to absorb it and turn that into a big fireball, and shockwaves and what not. It's not at all clear to me that a significant portion of a nuke's output will get converted into kinetic energy.
Bruce Willis died saving earth using nukes. I say go for it.
It was a nefarious excuse to put nuclear weapons in space.
Unfortunately, it looks like a hidden agenda is behind quite a bit of space policy.
Space solar power (now abandoned) was another attempt at getting weapons into space: collecting solar energy in space makes no economic sense, but it does make sense as an excuse to get a giant, city busting energy weapon into space.
Nuclear propulsion is another such attempt: it makes no sense for solar system exploration, but it does make sense as an excuse to get atom bombs into space.
I should add that the primary threat such an asteroid would pose are environmental, and not directly related to the amount of energy released by the blast. The threat is that dust from the impact would block light from the sun, cooling the earth and killing off plat and animal life. Alternatively, the danger is that it would produce tsunami stile waves that could wipe out costal life. Obviously, it is best if the asteroid is never able to touch the ground. I might also point that a very large blast is not much of a threat if it is too far above the surface of the earth.
Asteroid McAlmont
... can be arranged -- crash it into the Moon.
A small one might become near-surface metal ore for lunar mining.
A large one could de-circularise the Moon's orbit a bit, increasing the potential for tidal power.
We might even get lucky and end up with a pretty ring, like Saturn.
Using asteroid defense as an excuse to put nukes in space defeats the purpose of having nukes in space.
The power of nuclear weapons isn't the destruction, it's the THREAT of destruction. If we're going to put nukes in space to blow up stuff on earth, we want to make sure everyone knows that we have nukes in space to blow up stuff on earth. You're not going to convince your enemy that you have the ability to hit them first and that their first strike would be completely ineffective if your enemy doesn't know you have the nukes in space....
So if no one knows they are there and that they are there to blow up stuff on earth if necessary, what's the point?
paintball
If you have the power (actually delta-v) to put it into orbit, why not put it at the L1 point between the Sun and the Earth. Then, send a solar powered rock grinding machine to gradually reduce it to a fine powder. Slowly spray the powder into space (very easy because of the asteroid's negligible gravity) and you'll directly block out the sun. If the powder is fine enough, a few thousand cubic meters of rock should be enough to create a dust cloud hundred's of kilometers square. That'll be enough to reduce incident solar radiation a few percent (enough to compensate for global warming).
Of course the cloud will gradually blow away after a few years of solar wind, so you'll need to keep the machine going. This is a safety feature, you don't want this to be permanent!
If the asteroid has any appreciable spin it should be possible to convert it to into kinetic energy to move it off course.
Land a spacecraft at the asteroid's "equator". Extend a long tower/cable into space such that the end is considerably past the asteroid's "geo-sync" point. Securely attach the end of this tower/cable to the asteroid (may require just running a long cable around the entire equator). Get some robots to start collecting, digging up or mining asteroidal material.
The bigger the asteroid (and harder to move) the more rotational energy it will have to move it. Of course you need lots of time (like most methods).
Now, just like the speculative "space elevators" proposed for earth, transport the material up the tower/cable. Carefully timing the release of it from the space will send the material in one direction and the asteroid in another. Not fast but could be quite cheap; this system may not even need solar power because some power could be generated by the material as it is slung off beyond the geo-sync point.
Send up Bruce Willis in one of the two secret spare space shuttles. Give him a rough and tumble oil drilling crew and some suit case nuke. BAM! Done....
But this time, let's have Liv in a bikini or some lingerie.
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Nuke the whales!
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Although this is probably the best way to use nukes, the problem is in the sentence "Anything that has mass". How much polyethelyne will be required? You're using an extremely powerful energy source but coupling that with a mechanism that needs you to deliver a lot of mass to the asteroid (which is very expensive) to make it effective. Otherwise, with just a little plastic the conversion of nuclear energy to kinetic energy just won't be efficient.
A more efficient use of the (nuclear) energy in the weapons would be to set a reactor down on the surface and use the electricity generated it to power an accelerator to fire bits of the asteroid away. It would, however, take a long time of course (as well as add a lot of complexity). Another idea would be to use the shaped nuclear charge as you previously described but with dug up asteroidal material (couple tons of rocks brought up from the surface by robots?) instead of mass brought from earth. Vaporized rock might not be as good as plastic at absorbing soft X-rays but you could use a lot more. (You'd need radiation hardened robots of course to do this more than once).
Of course you could always forgo the nukes and use my idea for converting the spin rotation of the asteroid into kinetic energy (see comment below).
its not an an asteroid, its a space ship shaped like a rock???
then we are intergalactically screwed.
I propose a security through obscurity approach. When we know an asteroid comes our way, we do a massive blackout so the asteroind won't hit us.
Hopefully people are not mislead by the post -- it says "next decade", while the article writes "next century" is when the powerful new telescopes will be operational.
The great minds are pooling together to save us from impending doom...
Engineering researcher seeks answers to asteroid deflection
See if we can use the Goa'uld cargo ship's hyperdrive to generate a window the size of the asteroid and sustain it just long enough to pass right through Earth.
It's happened before.
Nice asteroids pinch.
Can you be Even More Awesome?!
"American can, should, must, and will blow up the moon."
"And we'll do it during a full moon so we make sure we get it all"
The article says "in the next century" new telescopes will come online to track these threating asteroids. I really doubt it's going to take until the 22nd century for these telescopes to arrive. Don't they mean this century?
The probability of an unacceptable collision in this century is ~2%.
Wow! Two percent is a huge number. I'm not sure how that "unacceptable" relates to these cases, but numbers in the range of whole percentage points are well above my personal something-must-be-done threshold.
"We reject as false the choice between our safety and our ideals." --The American President (20.1.2009)
I saw a presentation by the group behind this report. Using a nuke to divert an asteroid is not a crazy idea. They basically explode the nuke and cause a debris cloud of dust and gravel from the surface of the asteroid that provides the thrust to divert it.
They did very detailed simulations and it is very doubtful that the asteroid would break up like in the sci-fi shows... The parts that see the explosion break up into itty-bitty pieces and flow around the asteroid like a liquid... the interior of the asteroid remains intact. This is true for many different models of asteroid composition.
Schweickart makes the over-the-top claim that the study report is trying to push some secret nukes in space agenda. This is pure conjecture on his part. If he would have put his giant astronaut ego aside and spoke to the people who did the report he would have found out that it was done by people who had a strong aversion to nukes, and that the panel had initially tried to leave out the nuclear option or marginalize it for political reasons. But they were persuaded by the strength of the science in the nuclear advocates' arguments.
I was convinced... and I am a Pugwasher pacifist... and the people I know on the committee who were persuaded are also of the same ilk. But when you look at the analysis, you see that nukes do work. And in terms of energy imparted to the asteroid compared to launch mass, nothing else comes remotely close to the efficiency of nukes (E=mc^2 and all that.)
Yeah nukes are awful things. But so are ICBMs... and ICBMs are the basis for most of the launch vehicles used for peaceful space exploration. Why not beat swords into plowshares and start developing some asteroid-stopping nukes?
There are 10 types of people in this world, those who can count in binary and those who can't.
Apparently there are only 2 known asteroids out there that are large enough to penetrate our protective shield of space junk that encircles our planet. And one of those is Pluto.
I guess we could just ask them nicely to not hit us.
Or perhaps we could move the planet out of the way until it passes.
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In case you didn't know what he was talking about (and since I never actually saw this mentioned) his solution is almost certainly solar sails. It looks like a big fan in space that you literally ram into an asteroid and allow it to gently push it off course. Tow evokes the wrong mental image of the space shuttle hitching up to an asteroid to drag it out to space. It's not some brand new idea either. The Russians and Japanese have their own programs. I think Russian's solar sail program suffered a setback due to a launch failure or a crash. JAXA had some success in 2004 where they deployed two solar-sail types mock-ups for testing. They hype is: According to information posted on the Web site of The Planetary Society, which is arranging a separate solar sail mission, solar sails could accelerate continuously, theoretically achieving speeds of up to 160,000 kilometers per hour over a period of three years. (http://www.space.com/spacenews/archive04/jaxaarch_081704.html)
Uh....maybe it would be more practical to launch that type of mass from the moon?
I.e. -- What's the feasibility of extracting the needed mass from the moon and using rockets to launch from there?
Certainly the moon would be close enough. 1/6th gravity, so only 3 Ares-V rockets to launch the same mass?
However -- instead of applying that thrust to another mass...what would be the effect of attaching one or more rockets to the incoming asteroid? Could that thrust change the asteroid's direction? Is it possible to limit the amount of thrust so that the asteroid wouldn't be likely to break up?
If we had reached the "asteroid belt"...the cost of accelerating a mass from there would be small -- not much gravity to overcome.
If we had the tech -- what about moving several asteroids from the asteroid belt into earth, lunar or solar orbit -- so if we needed a large mass, we could toss one or more of the asteroids we've stored for that purpose at the incoming rock? Seems like all of these might be possible (but expensive and slow to setup) given our current tech -- but might give best possibility of deflecting a problem.
Or is this just too expensive to make sense?
Certainly there are others who agree with Hawkings that it is only a matter of time before an extinction level event hits earth again -- and that the only way for humans to survive it is by populating other planets or satellites in our solar system.
As for launching *mass* from the earth -- we need to develop something besides chemical rockets -- chemical fuel is limited and expensive to produce. The space elevator is one option -- though it has alot of problems, not the least of which it would be extremely vulnerable to terrorist attack.
But...a rail-gun could be used to launch mass (not likely humans) -- with the energy being electrical energy -- it could be recharged/powered via solar.
For getting humans launched -- what would be the hypothetical effect of launching humans via a rail-gun -- but for
the launch phase, have the humans suspended in water where our "weight" was near zero? Would that allow humans to survive such G-factors?
Curious...
Even if we become capable of protecting our home planet against asteroids, we are doomed as our civilisation has an expiration date which is due soon, considering Yellowstone's history of eruptions. Next time you go to see the geysers there remember that what is under this strange hot thing there has the capability to destroy all of us and in fact monitoring shows us that the underground magma is moving upwards.
Supervolcanoes killed nearly all of us 74 000 years ago, and we are all descendants of the few survivors, which explains our low DNA variation. Dinosaurs may have got extinct by volcanism too, and the asteroid that most people think killed them may have only killed the few survivors after the volcanism.
Many things in this world are uncertain, but there is one thing which we can be absolutely certain about: the death of our species as long as we keep living on Earth. Even if we hit an incoming asteroid, we will die from a supervolcano, and even if we manage to survive that we will cause nuclear winter nevertheless thanks to our stupidity.
The only reasonable thing to do when faced with so many dangers is to get out of here as soon as possible: Invest in spacecraft and research new propulsion techniques and life support technologies, so that we can colonise the Moon and Mars within a short timeframe. With one planet we are all doomed to extinction, either by asteroid, by volcanism, or war. With two or more planets to call home we can survive asteroids and volcanism, and maybe war if we don't invent any planetary-scale nuclear warheard. Of course a gamma ray burst, mini black hole randomly travelling around, or our own sun's death may still eradicate all of us even if we colonise the entire solar system, but this is solved easily by colonising more star systems once we invent even better propulsion systems and even better life support. The only possibilities we may find no solution for are war (if we get the technology to travel to the stars, some military people will surely find a way to nuke distant star systems as well!) and the heat death of the universe (but this isn't certain, therefore leaving only war as the only non-solvable threat to our civilisation).
If we develop the technology to save Earth from asteroids, and one endangers us, and a state (let's say the US) saves the whole planet by hitting it, then it wouldn't be unreasonable to say that the state which did so would have the right to ask for payment or something akin to taxes from other states, since hitting the asteroid saved them and their economy as well (it's no different that the service a military provides to a state). With this in mind, developing anti-asteroid technology could prove a lucrative income for whoever does so first!
During the cold war, the evil was "the communists". Then everyone realized that the majority of Russians were normal non-threatening people.
At the moment, the evil-threat-of-the-day is "the terrorists". Now, it may now seem like it at the moment, but the day will come when everyone realizes that the majority of Arabs are normal non-threatening people, too.
After people that fly planes into buildings and blow themselves up in busy markets, it's going to be pretty hard to top this with another credible human evil-threat-of-the-day.
So.... introducing the next evil (but the government will protect you) threat: asteroids!
with what? i heard somewhere the best way was to attach rockets and push them in a different orbit ? no?
Free speech was meant to be free for all... how can anyone grow up in a nanny state ?