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Space The Military

Should Nuclear Devices Be Kept On Hand To Protect Against Near Earth Objects? 272

Lasrick writes: Seth Baum ponders whether nuclear devices should be kept on hand for the purpose of destroying near-Earth objects (NEOs) that pose a threat to the planet. Baum acknowledges that "The risk posed by NEOs is not zero, but it is small relative to the risk posed by nuclear weapons." Even so, Baum writes, since the consequences of an NEO hitting the earth would be catastrophic, keeping 10 or 20 nuclear devices available might be a good idea, and would be "insignificant compared to the thousands now held in military arsenals."
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Should Nuclear Devices Be Kept On Hand To Protect Against Near Earth Objects?

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  • by tlambert ( 566799 ) on Wednesday June 17, 2015 @02:25PM (#49931437)

    You mean NEOs like Russia? You can't get any nearer to Earth than that.

    Probably "yes".

    • Near Earth Oligarchy?

    • by bill_mcgonigle ( 4333 ) * on Wednesday June 17, 2015 @03:10PM (#49931879) Homepage Journal

      You mean NEOs like Russia? You can't get any nearer to Earth than that.

      +1 - humor is a great way to get at the tough issues. To put it more bluntly, though: "no, nuclear devices should be kept on hand to protect against politicians". The nuclear-armed nations have not gone to war with each other, and they won't because nuclear weapons (along with ICBM's) ensure that politicians can't simply send poor boys off to die for their lustful ambition on wealth and power without also impulsively risking their own safety.

      This is unprecedented in the history of the nation state mechanism and has had major positive effects (if one considers empirical evidence rather than irrational fear). Sorry, it's not the pretty table at the UN that keeps bad leaders from misbehaving; until we can ban politicians, taking away their risk exposure would be the stupidest course of action conceivable. In the US only 5% of the population even trusts them to make sound decisions.

      Maybe I should just change my .sig to "incentives matter" - the fear-mongers love to pretend otherwise, so this never stops coming up.

      • by garyisabusyguy ( 732330 ) on Wednesday June 17, 2015 @03:33PM (#49932099)

        Thanks, you really summed up my response to the submitter, which would have been along the lines of, "What makes you think that we will ever NOT have nuclear weapons?"

        For the very reasons that you mention

  • by maroberts ( 15852 ) on Wednesday June 17, 2015 @02:25PM (#49931439) Homepage Journal

    Have you seen how much effect a nuke is likely to have on a significantly sized NEO? None whatso fucking ever. If an NEO is enough to wipe us out, it won't be screwed by a nuke.

    Also the ideal launch point for such a nuke would be from space, not Earth.

    • by Spazmania ( 174582 ) on Wednesday June 17, 2015 @02:30PM (#49931487) Homepage

      Yeah, the idea is idiotic. You blow up the NEO. Wonderful. The million pieces still have the same mass, velocity and therefore kinetic energy heading towards the planet.

      You don't blow up threatening space objects. Space is really big. All you do is give the object a little nudge while it's still far enough away. The little nudge is all it takes to miss the planet by a very large margin.

      • Comment removed (Score:5, Insightful)

        by account_deleted ( 4530225 ) on Wednesday June 17, 2015 @02:40PM (#49931567)
        Comment removed based on user account deletion
        • Re: (Score:3, Interesting)

          by Anonymous Coward

          1) burn up with.

          And where do they burn up? In the atmosphere.
          So where does the heat go? Into the atmosphere.

          Great, you've just incinerated an entire hemisphere at a mere 600 degrees rather than a single point at a few thousand.

          And since heat loss by radiation is proportional to the third power of the temperature, you've just made it take a lot longer to cool off.

          Yay.

          • by Urkki ( 668283 ) on Wednesday June 17, 2015 @03:12PM (#49931901)

            A meteorite which does not create a big crater will throw a lot less stuff up into the atmosphere, and will have much less global consequences. Getting a shower of smaller pieces would not be fun, but a single big impact penetrating deep into the crust with equal energy is worse.

            • by tnk1 ( 899206 ) on Wednesday June 17, 2015 @04:19PM (#49932513)

              You will be less likely to have a nuclear winter in that scenario, but something that hits with a gigaton of energy in one piece, is still going to release a gigaton, only over a larger area. It may not create a crater, but you'll probably have pretty much all the vegetation (and people) go up in smoke before the fireballs hit the ground. Lighting a continent on fire may be almost as bad as a direct impact. In fact it may be worse.

              The US changed from using huge megaton warheads on it's nuclear missiles because you actually get more effect from more, but smaller warheads which impact in a wider area. You're still dropping a few megatons per ICBM, but more surface area is affected.

              • A gigaton of energy spread over the entire face of the Earth isn't as bad as you make it sound.

                It's about 2T/km^2. It might be fun to watch, it might even raise temps a bit, but we're not going to all incinerate in hellfire.
          • by ArmoredDragon ( 3450605 ) on Wednesday June 17, 2015 @03:20PM (#49931985)

            If you blow up an object, I very much doubt that all of its pieces are still going to hit you. Some of them will go in the opposite direction, some will land in a slowly decaying orbit, and very few of them are likely to continue on their existing trajectory, and the few that do will have their kinetic energy reduced.

            That's assuming that the nuke actually blows it up. Nukes are FAR less effective in space because there's no atmosphere for the thermal energy to create a big shockwave, and there's no solid ground beneath it to amplify the intended direction of said shockwave.

            IMO if you want to blow up an NEO, you'll probably want some kind of kinetic weapon akin to a giant bullet, maybe a space born railgun or something.

            Still though, nudging is probably a better approach.

            • by Anonymous Coward on Wednesday June 17, 2015 @04:06PM (#49932391)

              The actual thermal effect of a nuclear weapon in the atmosphere is almost exclusively due to the fact that there is an atmosphere. In the immediate milliseconds following fission you get a very intense burst of soft x-rays, these are in turn absorbed in the first 2 miles or so of the atmosphere, superheating its component gases and causing it to radiate white, IR, and UV light. FUMP. This emitted IR/UV/White is the intensity that causes flash fires, vaporization, deflagration, etc.

              In a vacuum, a nuke goes off like a _very_ short flash bulb followed by a rapidly expanding cloud of _very_ whispy very superheated plasma that is composed of the nuke's fomer mass - only. What you don't see however is that the intense surge of X-rays does not get captured by anything, and instead continue on, rather lethally for hundreds to thousands of kilometers.

              A nuke against a NEO would best be used well ahead of time, in close proximity of 5 to .2 kilometers depending on the item's composition. Upon detonation the x-ray burst would get captured by the first few centimeters of the objects surface material facing the nuke. Material would boil off to several mm of depth, almost explosively for a few fractions of a second, and deliver a soft shove to the object conversely away from its boiled off char.

            • by Ichijo ( 607641 )

              Nukes are FAR less effective in space because there's no atmosphere for the thermal energy to create a big shockwave, and there's no solid ground beneath it to amplify the intended direction of said shockwave.

              So there's nothing for the explosion to push up against (Newton's Third Law). That makes sense.

              IMO if you want to blow up an NEO, you'll probably want some kind of kinetic weapon akin to a giant bullet, maybe a space born railgun or something.

              What's that going to push up against?

              • You are far better detonating the nuclear weapon above the side of the NEO to cause outgassing/ablation which will push the NEO off course so it likely will miss the Earth.

                Big kinetic hits won't help anywhere near as much.

            • by Rei ( 128717 )

              More than that not all of it hits you is that it doesn't all hit you at the same time. Earth has a massive radiative surface area; any delays between deposits of energy are hugely important.

              Anyway, the AC who replied first got it exactly right. Nuclear weapons in space are X-ray weapons that deliver force by boiling away the surfaces of objects (even at a distance). Not only is there an immediate direct effect from the boiling off of mass, but you're also creating a coma around the object which will also h

          • by ShanghaiBill ( 739463 ) on Wednesday June 17, 2015 @03:33PM (#49932097)

            And where do they burn up? In the atmosphere.

            No. First, the goal is to deflect it, not "blow it up". We have mapped out many, many thousands of NEOs, so if we find a "big one" that is likely to hit earth, we will probably have years of warning. Over that time frame, even a small nuke can easily change the course enough to miss earth. Heck, even a non-nuke kinetic energy hit would likely be enough. Second, even if we do blow it up, the chunks will spread out, and most of the pieces will miss earth entirely. Third, if they hit the atmosphere, and burn up, you only have the dust and debris from the NEO itself. If it impacts intact, it will throw up far more terrestrial material than just its own mass.

            Personal opinion: I think building nukes to stop NEOs is really dumb. It would be far better to spend the resources on detection, and exploration of the solar system. We should only build a nuke if we find an NEO with our name on it. There will be plenty of time if we focus on detection.

            • Heck, attaching a nuclear powered ion engine would work way better than a nuclear weapon. You might even be able to do a capture and use the NEO as orbital materials.

        • Radioactive Fallout (Score:4, Interesting)

          by Roger W Moore ( 538166 ) on Wednesday June 17, 2015 @02:55PM (#49931723) Journal
          You forgot:

          3) Scatter radioactive fallout with

          Still cancer takes longer to kill you that a massive asteroid impact followed by a decade of winter so I suppose it's a win?
      • by LWATCDR ( 28044 ) on Wednesday June 17, 2015 @02:40PM (#49931571) Homepage Journal

        Actually no it is not.
        You do not try and blow up the NEO. You try and deflect it. The idea is that you use the "shaped" nuclear charge design developed for the Orion.
        The NEO becomes the pusher plate and you nudge it so that it does not hit the earth.

        • I'd imagine that a surface detonation on an asteroid would cause enough mass to leave the asteroid, directionally, to nudge the rest away.
        • by TheCarp ( 96830 )

          This. Ideally you see it with plenty of warning so that you have time to deflect it. Shit maybe you use multiple nukes over the course of a week or two to nudge it into a safer flyby, possibly even one that impacts the moon (for 10 billion bonus points), or flings it off onto a path that will not meet up with us again.

          Shit should make an x-prize contest out of asteroid snooker. Prize to the company that demonstrates the capability to take an NEO, and deflect its flyby by an amount which would prove ability

        • You are assuming that the object is solid enough to be nudged from a single point

          I would much rather that we look into splattering it with a bunch of white material

          This will significantly alter the pressure that it receives from the sun and deflect every single piece of it that you can get 'paint' on

          • by LWATCDR ( 28044 )

            Should be no issue for a stone or nickel iron asteroid. Even for an ice or carbonaceous a series of smaller devices should not "shatter" one.
            "I would much rather that we look into splattering it with a bunch of white material"
            You would probably find the total mass needed would be very large compared to nuclear devices for the same total effect.
            a B61 is less than 700 lbs and can produce 600kt yield.
            a W32 is less than 70lbs can can yield 250t.

      • Irrelevant (Score:4, Insightful)

        by sycodon ( 149926 ) on Wednesday June 17, 2015 @02:47PM (#49931645)

        We have no delivery system, no fire control system, probably no software to guide it to the object, no information on a nuke's impact on the object, etc.

        It's like trying to decide if you should keep that 105 howitzer shell around when you have no gun, no one trained to use it, and no way to target anything with it.

        • We have no delivery system, no fire control system, probably no software to guide it to the object, no information on a nuke's impact on the object, etc.

          Speak for yourself

        • But we DO have Bruce Willis and Ben Affleck.
        • by TWX ( 665546 )
          Just about all of the pre-Apollo American launches of humans into space was done with ICBM rockets. Lots and lots of satellites were also launched with ex-ICBM Titans/Titan IIs, and Atlas rockets through the eighties were based on the ICBM version of the Atlas.

          Admittedly, these rockets were meant for orbital insertion or suborbital spaceflight, but that they have been adapted for nonhostile or less-hostile space applications implies that it would be possible to continue to do that, and that there is sof
        • by khallow ( 566160 )
          Nuclear weapons tend to be more forgiving of the delivery system than a howitzer shell. And we do have the rocketry thing working pretty well. I think delivery system, fire control, software, etc will just not be that hard.

          And one can always blow up a few asteroids to see if nukes work.
      • by AK Marc ( 707885 )
        The impact of a large NEO is in the energy being imparted to the planet surface, ejecting additional material, earthquakes, tsunamis and other impact artifacts. The "damage" from heating of the air on entry is inconsequential. So spreading the entry to millions of small pieces that burn up in the atmosphere is a better outcome.
      • by Chris Katko ( 2923353 ) on Wednesday June 17, 2015 @02:53PM (#49931701)
        While on a practical sense you may be right, the idea that they'll have the same velocity is completely false.

        That's like saying detonating TNT in front of a semi-truck on the highway means it'll fly the same speed in another direction. Or that it'll move in the same direction it once was. Or if you detonated TNT in the water near a ship, it'd still go the exact same direction.

        Where a near-earth object goes after being hit by, or being nearby, a large explosion is entirely dependent on the position and composition of the objects. But one thing that will absolutely not happen is them magically going the same direction they were.
      • by Kjella ( 173770 )

        You don't blow up threatening space objects. Space is really big. All you do is give the object a little nudge while it's still far enough away.

        Of course a "little nudge" is relative if you're talking objects of any serious consequence. A 100m asteroid - a decently sized H-bomb on impact - is likely to weigh >1,000,000 kg. That's a lot of inertia to nudge even a little bit. The smallest ones (<15m) we don't need to do something about, the biggest ones we can't do anything about (the dino killer was a trillion tons) so there's a few in the middle that we maybe could, but statistically it's like an entire city struck by lightning - nasty death

      • by njnnja ( 2833511 ) on Wednesday June 17, 2015 @03:18PM (#49931957)

        RTFA [nasa.gov] They specifically look at a standoff explosion versus a surface or subsurface explosion and prefer the standoff explosion precisely because they are aware of the possibility of blowing something up with a nuclear weapon. Amazingly enough, the professional rocket scientists at NASA actually considered the consequences of the alternative tactics before making their recommendation

      • by eth1 ( 94901 )

        Yeah, the idea is idiotic. You blow up the NEO. Wonderful. The million pieces still have the same mass, velocity and therefore kinetic energy heading towards the planet.

        You don't blow up threatening space objects. Space is really big. All you do is give the object a little nudge while it's still far enough away. The little nudge is all it takes to miss the planet by a very large margin.

        OK, I'm going to stand 50 meters away from you and shoot you with a shotgun. I'll give you a choice: would you prefer me to use a slug, or an equivalent mass of birdshot?

        Also, blow it up far enough away, and the center of mass of the object could pass right through Earth without any of the bits actually hitting us.

      • You blow up the NEO. Wonderful. The million pieces still have the same mass, velocity and therefore kinetic energy heading towards the planet.

        And now all those pieces are radioactive to boot.

        I've read some cockamamie arguments from people who are desperate to make sure we keep our nuclear weapons, but this one is a real hoot.

      • And you, like most people missed the point.

        If you have one rock hit, all its energy is concentrated. The atmosphere isn't going to slow it down as much as it will collectively slow down 'millions'

        With millions, some of them ARE going to miss the planet, and some will be vaporized by the blasts in space, there you've already lowered the total energy involved with hitting earth. Not much possibly, but some.

        Would you rather a hail ball the size of a golf ball hit your house, and one each hitting every house

      • Maybe the nuclear blast is the little nudge for a big enough object.

    • Have you seen how much effect a nuke is likely to have on a significantly sized NEO? If an NEO is enough to wipe us out, it won't be screwed by a nuke.

      Wouldn't that depend on whether or not we sent up a crew of oil rig drill operators to drill into the NEO first, before inserting the nuke?

      • Only if space madness is a factor and Bruce Willis leads the team. Otherwise we're proper fucked.

    • by Tuidjy ( 321055 ) on Wednesday June 17, 2015 @02:31PM (#49931507)

      Yeah, and I think that the danger from any NEO that is small enough to be affected by those space based nukes is way, way, WAY less than the danger from space based nukes that can be seized, one way or another, by some nutcase... leaving aside the fact that those who thinks they are a good idea in the first place are nutbags themselves.

    • Also the ideal launch point for such a nuke would be from space, not Earth.

      So are you saying...nuke it from orbit?

      We could nuke it from orbit with enough nukes that the NEO trajectory could be adjusted to come into earth orbit. Essentially we could nuke it into orbit from orbit to nuke it repeatedly while it orbits, dawg!

      One last one... That's no Moon! That's a NEO...it really is the One! Just call it Mr. Anderson.

    • by pr0t0 ( 216378 ) on Wednesday June 17, 2015 @02:35PM (#49931521)

      Agreed. The question the article poses presupposes that nuclear devices CAN protect against NEOs. Most research in the field answers the question with a resounding "no". The best use of a nuclear weapon against a NEO would be to detonate several, in succession, to slightly alter the course of the NEO or to change its velocity. But as maroberts intimated, this would have to be done at a significant distance from Earth...probably near or past Jupiter's orbit at a minimum.

      • by Moses48 ( 1849872 ) on Wednesday June 17, 2015 @02:57PM (#49931745)

        The article quotes a NASA study from 2007 on the best way to "deflecting NEOs". They found nuclear devices to be "10-100 times more effective than the non-nuclear alternatives analyzed in this study." You are actually saying what the article is saying. The article doesn't say the nukes are to explode the NEO, leave it to Slashdot to have a misleading summary.

    • by Dunbal ( 464142 ) * on Wednesday June 17, 2015 @02:38PM (#49931549)
      Most of the damage from a nuclear weapon comes from the overpressure created by superheated air. There's no air in space. So apart from being hit by tiny fragments of bomb casing and part of the object being heated a little not much would happen, even if detonated on the surface of such an object. Drilling into it on the other hand might - MIGHT work. Now, how'd you like to drill a couple hundred feet into solid iron-nickel alloy?
      • Re: (Score:3, Funny)

        With a NUCLEAR DRILL!
      • Actually that's the entire point. Sure movies have it dead wrong. But the general idea is to gently boil off material over the entire side giving it a small kick. Several would be needed in all likelihood and hopefully at least one orbit ahead of time. At the very least several AU of distance would be needed.

        There are much better ways of handling it though and the insignificant chance of a deadly object we can deflect with that method is likely dwarfed with the chance of incompetence and mishandling
      • Roughly 4 out of 5 asteroids are Chondrites - basically giant piles of fused gravel. Nickel-iron asteroids only account for ~5% of known bodies.

        Of course, breaking up an asteroid will not help if you don't deflect a significant portion of the mass. 40 million tons of stuff traveling at thousands of kilometers per second carries a certain amount of energy, and that energy isn't going to go away just because you break it up into 40 million 1-ton bits.
        =Smidge=

    • by Moses48 ( 1849872 ) on Wednesday June 17, 2015 @02:39PM (#49931559)

      The summary is wrong. TFA says the nuke would be for changing the trajectory of the NEO, not destroy the NEO. It also found nukes to be better than other methods of changing trajectories.

    • I agree with your point, clicked on the link figuring it was medium.com or something, but no, it was The Bulletin of Atomic Scientists.

      Really? They should have known better. Atomic scientists have really gone downhill from the days of Von Neumann and Feynman.
  • by pj2541 ( 600359 ) on Wednesday June 17, 2015 @02:26PM (#49931441)
    And what delivery mechanism do you propose we have ready for those devices? Its not like we have superorbital spacecraft just lying around.
    • Why the two top secret X-71 space shuttles, Freedom and Independence of course.

    • by AK Marc ( 707885 )
      The most sense is to build a nuclear launch facility on the dark side of the moon, with rockets that are designed to be accurate in space, but unable to target the Earth, so there's no chance for it to be used against us. Though, not sure if that's possible. You want them in a stable orbit (the moon is moving away, not closer) and you want them as far out of the gravity well as possible. Aside from a firing station in a lagrange point, which is less stable than the moon, the moon seems the most logical p
      • The most sense is to build a nuclear launch facility on the dark side of the moon, with rockets that are designed to be accurate in space, but unable to target the Earth,

        I'm interested in the notion of a rocket on the moon that can reach a NEO but NOT the Earth.

        Alas, ain't going to happen. If a rocket can do lunar escape speed, it can hit the Earth. And lunar escape speed is pretty much mandatory for hitting an NEO (unless the NEO passes within about one lunar diameter of the moon)....

      • Of course the earth can be targeted from dark side of moon, and vice versa.

        • by AK Marc ( 707885 )
          So your answer is the typical "If I can't think of a solution in 10 seconds, that's proof it's impossible" Slashdot answer.

          I can think of multiple ways to solve the answer. But now, it'll be a personal issue where you'll assert I'm wrong, rather than thinking about the issue, so there's no point to try to describe how to "solve" the issue.
    • by TWX ( 665546 )
      If one puts nuclear devices into orbit, I expect that would would place solid-fuel rockets into orbit attached to the nukes. So long as they're not segmented with O-rings like the ones on the Space Shuttle they can probably remain up there service-free for decades and still function as intended.
  • by rogoshen1 ( 2922505 ) on Wednesday June 17, 2015 @02:26PM (#49931449)

    "keeping 10 or 20 nuclear devices available might be a good idea..."
    "insignificant compared to the thousands now held in military arsenals."

    Okay, so a solved problem? Got it.

  • by ihtoit ( 3393327 ) on Wednesday June 17, 2015 @02:27PM (#49931459)

    in fact, we didn't see ANY of the more recent impacts coming until the dust had settled. So what fucking use is a nuke again?

    • by TWX ( 665546 )
      The recent impacts also weren't large enough to cause more than regional damage. Didn't even reach regional surface devastation like Tunguska or regional geologic devastation like Barringer Crater.

      I'm assuming that we'll never be able to reliably detect impactors as small as Tunguska, but we might be able to detect Barringer-sized objects if we make an effort to look for them.
  • How could 10 or 20 nuclear devices help against any significant near earth object?
    • by Sowelu ( 713889 )

      Give it a tiny nudge when it's far away. Seems like you'd want very different kinds of missiles to do that though, designed to fine tune their course in space instead of air.

  • by dskoll ( 99328 )

    A nuke is unlikely to have much effect on anything big, other than to break off additional chunks that are harder to stop and track.

  • by bluefoxlucid ( 723572 ) on Wednesday June 17, 2015 @02:39PM (#49931565) Homepage Journal

    "The risk posed by NEOs is not zero, but it is small relative to the risk posed by nuclear weapons." Even so, Baum writes, since the consequences of an NEO hitting the earth would be catastrophic

    Wrong. The risk posed by NEOs is small in probability and extremely high in magnitude; the risk posed by nuclear weapons is larger in probability and smaller in magnitude. Space rock impacts cause mass extinctions; nuclear weapons detonations cause international incidents and poorly-defined human responses.

    We have a fantasy that one nation launching a nuke will result in all nations nuking each other until the earth is a ball of slag; a more rational mind recognizes MAD as suggesting one nation launching a nuke will result in all nations reducing that nation to a ginormous glass parking lot. In reality, we haven't seen that situation, and our assessment of human psychology suggests it's more likely that a single strike (rather than constant, ongoing bombing) would result in shock, hesitation, and a lot of talking; ongoing nuclear bombing of a single nation would probably result in all other nations shaking like water-laden chihuahuas while trying to talk down the offenders (see Germany. Twice. With all of Europe wetting itself both times).

    Nuclear war has a low but significant probability, itself spanning a wide berth of probable outcomes with impacts ranging from nothing notable to devastation. The human race would survive even in the worst projections, just bombed back into the stone age. NEO impacts have an insignificant but real probability, when limiting our view to those objects which would destroy the earth. Limiting nukes to "slag the human race back into the stone age" produces a similarly insignificant but real probability, more attainable by joint intent of all world leaders but hardly more likely; expanding NEO impacts to "a range of possible outcomes from smashing buildings to vaporizing all life off the planet" and scaling each magnitude of impact against the various magnitudes of impact of nuclear war immediately demonstrates that we take meteor impacts pretty frequently, most hitting uninhabited areas or blowing up in the sky with no damage, so nuclear war seems vaguely more likely in all scenarios.

    The absolute outcome of a planet-killer tells you it's easier to hide from nuclear war. A few nukes are an acceptable trade-off, since disarmament is impossible and creates its own risks (i.e. secret nuclear stockpiles--if you really disarm, how do you know the other guy isn't lying, and ready to nuke you when it's clear you really have no nukes?)

    • see Germany. Twice. With all of Europe wetting itself both times

      I see you're talking about Hitler......what is the second time?

  • David Morrison of SETI has said only need to nudge it by impacting it with a spacecraft, that will change it's trajectory [of course need to do it way ahead before impact, and careful calculations]. Other than that, sounds like excuse to keep some A or H bombs lying around. And of course using them on a NEO is very dramatic, add Bruce Willis and you have a classic (there was another asteroid movie that came out same time, it has been forgotten). Plus ever since the movie "Marooned," a common movie plot of p
    • I think robot controlled solar sails would even work to adjust trajectories, given sufficient time and warning.

      Nukes? If there is a suddenly detected chunk of rock/ice/metallic whatever that big, that close, probably wouldn't help
      much.

      I prefer nudging even with nukes, not trying to blow up the object.

  • by tekrat ( 242117 ) on Wednesday June 17, 2015 @02:53PM (#49931695) Homepage Journal

    We have nothing that will take a nuke far out enough to use it against a NEO. I am assuming that this is one of those scenarios where we discover the object too late to do anything but attempt blowing it up. Therefore it's what, between the earth and the moon?

    All our launch systems are LEO, and then use gravity assist slingshots to get themselves into the outer solar system. We have NOTHING that can go directly to the target. Therefore we are essentially screwed, because by the time we got the nuke to the target (read as days of orbits), it's already 15 minutes away from impact, in which case, the nuke isn't going to do much except shut down the electrical grid from the EMP, before we are wiped out.

  • I think you want to land nuclear reactors with ion thusters on the surface of the NEO, a long time back from possible impact.
    Ideally with some technology that can convert material on the object to the right kind of ionized gas.

    Energy = mv^2 /2 so you accelerate the ions in a beam at extremely high velocity, electrically.

    You need a control system to only send out the ion beam each time a tumbling object is facing the correct way.

    You run the ion thrusters for months or years, and hope for the best.

  • This sounds like someone just trying to justify not getting rid of all of our nukes.
    • Getting rid of all of our nukes would be about the dumbest thing imaginable. They're pretty much the only reason we didn't have WWIII and maybe WWIV.
      • Getting rid of all of our nukes would be about the dumbest thing imaginable. They're pretty much the only reason we didn't have WWIII and maybe WWIV.

        Mutual Assured Destruction was just ... mad.

        That said, what have our nukes done to prevent the war on terror? What have they done to prevent all the other wars we have fought in since WWII? You can make a (dubious) claim that the nukes on their own prevented other nations from attacking the US directly if you want, but conflict doesn't occur in vacuo on this planet. There are other factors that are arguably more critical to preventing war.

        • Mutual Assured Destruction was just ... mad.

          And very scary, but it did work.

          That said, what have our nukes done to prevent the war on terror?

          An anti-insurgency campaign in a couple of minor nations is not in the same weight class as a global conflict between 1st world powers. Allow me to demonstrate:

          WWI Casualties: 17 Million
          WWII Casualties: 60 Million
          War on Terror Casualties: Debatable but likely less than 250k.

          As you can see the other conflicts are roughly two orders of magnitude larger.

          What have they done to prevent all the other wars we have fought in since WWII?

          Congress hasn't declared war since 1941. If you want to count authorizations of military force then no, of course nu

  • 1. Nuclear devices are ineffective in space. This means you will have to use BIG ones, or you will have to use them early to nudge the object onto a different path. Bigger devices are harder to throw into space and detection and targeting of dangerous objects makes the problem all that harder.

    2. Nuclear weapons in space is in itself insane and banned by multiple international agreements due to the danger they pose.

    3. Nuclear material in orbit is dangerous because what goes up, must come down. We don't pu

    • Wow, you really spew a lot of things without knowledge of the subject:

      1. Wrong, effective thrust producers in space when used as surface or subsurface boost.
      2. nuclear weapons in space have already existed. insanity not a valid point to raise as the weapons themselves sufficient to destroy civilization many times over exist (though not enough to kill all humans, contrary to popular belief) and are under the control of POLITICIANS. Logic and sanity are left at the door.
      3 nuclear weapons launched by rocket

    • 1. Nuclear devices are ineffective in space.

      Not the case. See Project Orion [wikipedia.org].

      will have to use them early to nudge the object onto a different path

      This would be the case for any asteroid defense and we're already capable of detecting and track most objects large enough to cause serious concern. With more investment, we'll only be getting better and be able to detect smaller and smaller objects.

      banned by multiple international agreements

      Banned due to potential for a space arms race over a potential war. Doesn't apply in case of joint global asteroid defense.

      We don't put nuclear power generators in space for a reason

      We can and regularly do send nuclear [wikipedia.org] power [extremetech.com] generators [oocities.org] into space, including fully-featured nuclear [wikipedia.org] reactors [wikipedia.org]

  • Why don't we consider this question after we've gone to Mars and tried it there..or Jupiter perhaps. We should figure out if the idea actually works before we consider deploying it at home, what say? Humans are terribly at risk assessment. We didn't really have a clue what we were unleashing when we set off our first nuclear tests. We did learn quickly...sorta. However, using a nuke against an NEO is something we've only theorized about. We should do some testing. In a place that's not actually remot

  • by redwraith94 ( 1311731 ) on Wednesday June 17, 2015 @03:04PM (#49931809)
    So you are going to force China, and Russia to give up the arsenals that they aren't getting rid of? There is really only one way to do that, which would be to destroy them. Nukes are here for the foreseeable future. Let the idea of forcing other people to get rid of something they own out of your mind. The more people that do that, the less likely they will be used.

    My favorite idea for getting rid of NEOs is a super powerful laser, that would ablate the surface, and gently nudge the thing off course.

    I am sure there are certain scenarios where you could detonate a nuke nearby it, and let the resulting shockwave do the same thing. However the modeling that we have for atmospheric shockwaves is inaccurate, and large object surface will be anything but smooth. Also most celestial objects will be moving much faster than our missiles, so we may not actually have time to intercept them.

    I mean no offense to you, OP, however what you purpose isn't possible, that is trimming down the arsenals to only a dozen or so.

    A perfect example of this; does Russia still have 152mm nuclear artillery shells? I realize that the were 'destroyed' because of the Start treaty, but I find it very interesting that that is the larger caliber available for the Armata T-14 platform. Which shows another dilemma; can you trust any of the nations that have them to honestly tell you what they have, when first strike capability is so very, very important? They are going to a hell of a-lot of trouble to be able to air-lift 400 tanks to 'anywhere' in the globe (or about 7,000 km) to drop just 400 tanks, which in the scheme of a war with Nato, would be overall fairly useless. Along with having only 80 transports for the entire country is fairly risky. If I were them, that is how I would play it.

    As another example, who attempted to 'steal' the nukes via the Minot-Barksdale air base incident? Very few people have the authority to order nukes flown in launch position over the US, in a time of 'peace' (such as that is). Everyone was quietly 'transferred', and no one was court martialed, Which means, that the officers involved in the actual transfer had valid signatures, and they were protecting someone higher up. That's our own country, do you really believe a foreign power is going to be more honest? They won't be, as it isn't the interest of any Government that needs power to enforce its will (i.e., all of them).

    Government's are just extensions of the people, and they will behave just like people (i.e. lie to you).
  • by crunchygranola ( 1954152 ) on Wednesday June 17, 2015 @03:22PM (#49932015)

    There are wide variety of possible cosmic collision threats - with only rare once-a-century (or less frequent) size events being candidates for any sort of deflection scheme. More frequent ones we can absorb with minimal damage. The 2013 Chelyabinsk event was a 20 meter class asteroid, and we get hit with a few of these a year. Even a repeat of the Chelyabinsk over a much larger city would not be catastrophic, as a natural catastrophe it might rank as a "major storm" in terms of damage potential.

    It is larger asteroids, above the 20 meter size, that are destructive enough to consider an international interception mission.

    Barringer Crater in Arizona is an example of a 50 meter object (a once in a millennium event), such an impact would be highly destructive in a populated area. Current collision threat programs have identified 96% of the "civilization ender" 1+ km class objects (once in a million year event), and are moving toward identifying 90% of the 140 meter class (once in 10,000 years).

    The ideal method dog dealing with any collision threat is to detect it long in advance, accurately measure its trajectory, and then modify it just enough to avoid a predicted collision years later (perhaps many decades later, even centuries later for really big ones). Smaller objects need smaller nudges and can be diverted at later dates than big ones. An aggressive monitoring system is the first line of defense, without detection there can be no defense, and the better your detection the easier deflection becomes, and the cost of monitoring is much less than a single interception mission.

    A variety of nudging techniques have been proposed [nasa.gov]: kinetic collision diversion, gravity attractor tugs, and nuclear deflection schemes primarily, but all of them are in early stages of development and have some promise. Different deflection schemes might be needed based on the nature of the threat object (size, physical nature, etc.).

    Until we have candidate defection systems to evaluate, and actually test, it is way premature to discuss storing nuclear devices for this purpose. Probably storing a ready made device would be of no value. When we detect a threat requiring deflection we would first need to organize the whole launch and space probe project, which would likely take a few years (assuming warning times on the order of decade) during which time a nuclear device customized to the mission could be manufactured as needed. If the world decides (after suitable development and testing) that a ready-to-launch-on-short notice vehicle is a good idea to deal with small threats detected months in advance, and it is determined that a nuclear device is the proper technique, then we would only need one such system to be built and kept ready - with a grand total of one special purpose nuclear device.

    • and it is determined that a nuclear device is the proper technique, then we would only need one such system to be built and kept ready - with a grand total of one special purpose nuclear device.

      I like the way you assume nothing could possibly go wrong with your single launch. Be a shame to have one special purpose nuclear device fall onto the moon because the launch vehicle screwed up....

      Trust me. Don't build special purpose devices (which require testing in any case), and don't just keep one around. Ke

      • Actually I should have simply said that only "one system be kept ready", not that only one should be built. So make it two, even three for back-up. Well established launch systems have reliability rates of 95%, so high levels of redundancy are not really called for. Still not 10-20. And it still only is needed for one corner case of relatively small threat magnitude. More serious threat call for special missions and have threat timelines long enough to organize them.

        Actually testing the interception system

  • Shouldn't we first determine if nuclear weapons would even be effective against a NEO before asking if we should keep them on hand?

  • Comment removed based on user account deletion
    • Deflection:possibly, but into what or where?

      Easy: away from Earth. It is only the fact that at one point in its multi-billion year orbital history that it happens to come within 4000 miles of the Earth's center of mass that we care about. If we make it miss, by even a small distance, it will continue (typically) for billions of years more.

      Asteroid deflections is really just a process of cosmic sheepherding - keeping the orbits of the big rocks from becoming (and remaining) Earth intercepting ones.

  • Is this guy assuming we will eventually eliminate all of the thousands of nuclear weapons we currently have? What in the world does the poster mean by "on hand"?

    The article's title is "Should nuclear devices be used to stop asteroids?". Makes me wonder if the submitter read TFA.

    The article itself is kind of dumb. It talks about rethinking the Outer Space Treaty that bans nuclear weapons in space. If there was a global threat on the way, the time it would take to arm and configure a rocket to send the weapon

  • The first question regarding what to do if a giant meteorite is heading for collision with Earth should be, "Is humanity worth saving?"

    Let's start by making a list of reasons why it's important to save humanity. And I'm sorry, "Because it's us!" is not persuasive. Who wants to go first?

  • ..it's the only way to be...wait, oh damn, that won't work.

    Never mind.

  • by dweller_below ( 136040 ) on Wednesday June 17, 2015 @05:33PM (#49933033)
    If you actually want to effectively counter the "Dinosaur Killer" scenario, the best answer is early detection and a large "Orion" ship. See: https://en.wikipedia.org/wiki/... [wikipedia.org]

    We could have build a large Orion propulsion ship anytime in the last 40 years. It would probably cost less than an aircraft carrier. A large Orion propulsion ship could get almost anywhere in the inner solar system in a few weeks. And the propulsion system will work just fine to redirect another large mass. Yes, there will be a bunch of fallout damage from the initial take-off, but we can decide where to place it. and the fallout damage from Orion's propulsion is tiny compared to the damage from an asteroid strike.

    I have always hoped that there was a secret plan to convert our offensive arsenal into Orion propulsion if the need occurred.

So you think that money is the root of all evil. Have you ever asked what is the root of money? -- Ayn Rand

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