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Space Earth Technology

New Best Way To Nuke a Short-Notice Asteroid 311

doug141 writes "A scientist proposes the best way to deal with an asteroid on short notice is to hit it with an impactor, followed by a nuke in the crater. From the article: 'Bong Wie, director of the Asteroid Deflection Research Center at Iowa State University, described the system his team is developing to attendees at the International Space Development Conference in La Jolla, Calif., on May 23. The annual National Space Society gathering attracted hundreds from the space industry around the world. An anti-asteroid spacecraft would deliver a nuclear warhead to destroy an incoming threat before it could reach Earth, Wie said. The two-section spacecraft would consist of a kinetic energy impactor that would separate before arrival and blast a crater in the asteroid. The other half of the spacecraft would carry the nuclear weapon, which would then explode inside the crater after the vehicle impacted.'"
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New Best Way To Nuke a Short-Notice Asteroid

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  • by stoofa ( 524247 ) on Thursday May 30, 2013 @04:37AM (#43858461)
    ...his name is the sound his plan would make.

    Bong Wie!
  • by Swampash ( 1131503 ) on Thursday May 30, 2013 @04:38AM (#43858465)

    Wouldn't it be more efficient to just... push the asteroid out of the way?

    • by heypete ( 60671 ) <pete@heypete.com> on Thursday May 30, 2013 @04:41AM (#43858493) Homepage

      If you have the time for it, sure.

      As the article says,

      A nuclear weapon is the only thing that would work against an asteroid on short notice, Wie added. Other systems designed to divert an asteroid such as tugboats, gravity tractors, solar sails and mass drivers would require 10 or 20 years of advance notice.

      It's not really possible to put big rocket motors on an asteroid and push it out of the way, as transporting enough fuel to the asteroid would be unbelievably expensive and likely infeasible with current technology.

    • Wouldn't it be more efficient to just... push the asteroid out of the way?

      Actually, probably an easier and more reliable way would be to simply let a hardened nuke hit the asteroid and have it explode some 10-15 meters below the surface. We already have these (or rather, you Americans do - look up B61 Mod 11), and these are built to penetrate reinforced concrete. The majority of asteroids has a vastly softer composition. The plasma ejected from the explosion will make its own nozzle on-the-fly, so as to speak.

    • What about when it's the size of a small city?

  • by MichaelSmith ( 789609 ) on Thursday May 30, 2013 @05:05AM (#43858561) Homepage Journal

    Any object small enough to be destroyed this way would be best avoided by evacuating the locale where it is going to hit.

    • Re:But Why? (Score:5, Funny)

      by Metabolife ( 961249 ) on Thursday May 30, 2013 @05:09AM (#43858575)
      Pack your bags kids! We're going to the moon!
    • Re:But Why? (Score:5, Insightful)

      by Verunks ( 1000826 ) on Thursday May 30, 2013 @05:12AM (#43858595)

      because it's less expensive than rebuild a city?

      • Re:But Why? (Score:4, Insightful)

        by K. S. Kyosuke ( 729550 ) on Thursday May 30, 2013 @06:14AM (#43858843)
        Letting it wipe out all life completely is the cheapest option at all - you don't spend a cent on rebuilding anything. :-)
        • That's exactly what I think AI induced war will bring... Robots will just reason into the best way to end most problems on the planet would be to get rid of the humans.

          (kinda like making cars a lot less safe will cut down on the number of cancer patients, etc.)

    • Re:But Why? (Score:5, Insightful)

      by MacGyver2210 ( 1053110 ) on Thursday May 30, 2013 @05:18AM (#43858619)

      It's not DESTROYING the incoming asteroid, it's breaking it up into smaller pieces and changing their trajectory. The point isn't to get the asteroid to miss us entirely, it's to make it not hit us all at once in one spot.

      Small impacts would probably be pretty devastating for those that survive the atmosphere(think early impacts from Armageddon, etc) but at least it wouldn't cause a near-extinction of all life as a giant single impact could.

      • by xelah ( 176252 )
        The politics must be fantastic.......break up an asteroid heading for New York and send some of the pieces to China/Russia/somewhere that could moan with violence. Or, of course, vice versa if the US legitimizes it.
    • And if it is big enough, we'll have to deal with the remaining debris of size asteroid/x, and if it is even bigger, we'll have to deal with each y debris-of-debris from the x debris pieces etc ... well, a good way to get rid of all nuclear warheads we currently have on Earth..
    • by necro81 ( 917438 )

      Any object small enough to be destroyed this way would be best avoided by evacuating the locale where it is going to hit

      In terms of having confidence that you'll save lives, you may be correct. In terms of property damage - it is difficult to be sure. An asteroid delivering even a glancing blow to a population center could easily cause several billion dollars of damage. I expect the whole cost of this program would be less than that.

      A tough thing with small objects like this is that their trajectory

  • Spin spin.. (Score:4, Informative)

    by hantms ( 2527172 ) on Thursday May 30, 2013 @05:08AM (#43858571)

    Don't asteroids usually spin? If you blast a crater on one side, then you have some serious aiming to do to hit the crater?

    • Re: (Score:3, Funny)

      by hantms ( 2527172 )

      Don't asteroids usually spin? If you blast a crater on one side, then you have some serious aiming to do to hit the crater?

      Then again, clearly it's possible to hit with photon torpedoes, and using the Force.

    • Planets and moons also spin, what's your point?

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      I'm not sure aiming would be a huge problem, computers are pretty good at that sort of thing. You'd probably have to have the two payloads on slightly different trajectories (one coming in from a bit of an angle) following separation to account for the 'roid's rotation.Imagine the asteroid at the centre of a clock face. First impactor would hit from a 5-to-12 direction, the nuclear warhead a few seconds later from 12 Oclock. This would require some manoeuvring after an early separation, but shouldn't be par

    • Re:Spin spin.. (Score:5, Informative)

      by AC-x ( 735297 ) on Thursday May 30, 2013 @05:49AM (#43858727)

      Rocket scientists have managed to aim spacecraft to very specific points on spinning bodies before, I'm sure they'll manage.

      • by meglon ( 1001833 )
        Yeh....

        It's easy to hit something once. When what you're trying to hit it with is moving at a basic set speed which may not allow enough change to compensate for the spin, then it becomes more difficult. Then, you have to think of it as closing velocity.... you get one shot, and that's pretty much it. If you miss, the first impact does nothing for you. The warhead part isn't going to be able to turn around, race ahead of the object, turn back around, and hit it in that hole (or try to) again.

        I reall
    • Don't asteroids usually spin? If you blast a crater on one side, then you have some serious aiming to do to hit the crater?

      We have to try SOMETHING, even if it's a disgustingly planned attack almost guaranteed to fail.

  • by will_die ( 586523 ) on Thursday May 30, 2013 @05:09AM (#43858577) Homepage
    Looking at the article it does not look like they take into account the rotation of the asteroid. So do asteroids not rotate?
    Even with a small rotation your nuclear bomb would miss the crater without some extra guidance which is not shown.
    • by AC-x ( 735297 ) on Thursday May 30, 2013 @05:47AM (#43858719)

      What, you think someone smart enough to design a mission to intercept an asteroid with an impactor and hit that crater with a nuke wouldn't know to take the spin into account?

      All this study was doing is working out whether the idea would work, not designing a complete mission profile for a specific asteroid.

      • what's happens when your crater causing nudge furthers changes the rotation?you literally have to plan for the final rotation change after the kinetic crater impact.

        much simpler send up more than one nuke. Pepper the asteroid with them one after another after another.

        We have thousands why skimp. More is always better.

        • Re: (Score:2, Insightful)

          by Anonymous Coward

          If we have a 1% risk of a rocket detonating during launch there might be reason to design a mission that only sends two rather than 1000.

          • by Dins ( 2538550 )
            If faced with the extinction of the human race, let's send as many as necessary to nearly guarantee destruction/deflection of the asteroid. If that means one or two accidentally explode on launch, so be it. Besides, a nuclear missile exploding probably doesn't mean a nuclear detonation. Scattered radiation, sure, but not a nuclear detonation. Better than losing all of us.
      • What, you think someone smart enough to design a mission to intercept an asteroid with an impactor and hit that crater with a nuke wouldn't know to take the spin into account?

        All this study was doing is working out whether the idea would work, not designing a complete mission profile for a specific asteroid.

        You know what you're doing in your comment? It's called assuming. The parent's question is pefectly valid and deserved a damned good discussion!

      • People smart enough to send a satellite into a martian orbit didn't know to convert standard to metric, so yeah, it's possible that they could overlook something in their calculations.

    • by gmuslera ( 3436 )
      Not just spin, but also moves, usually at high enough speeds to not be there anymore by the time the 2nd portion of the rocket would hit, unless you are coming from the same direction it goes. The second part will have to hit a different place, at a different time, and taking into account whatever change does the impactor on the rotation or speed on the asteroid (shouldn't be so big difference, if the impactor manages to change something probably the nuke wouldn't be needed anyway).
  • by CuteSteveJobs ( 1343851 ) on Thursday May 30, 2013 @05:17AM (#43858615)
    A nudge I can understand if there is any way to create enough energy to push something that large out of the way, but what is the point of the nuke? How do we know this doesn't end up creating lots of smaller asteroids?

    "The goal would be to fragment the asteroid into many pieces, which would then disperse along separate trajectories."
    Uhhh. Ok.

    "Wie believes that up to 99 percent or more of the asteroid pieces could end up missing the Earth, greatly limiting the impact on the planet."
    Hell of a bet to take on a hunch. Where are the simulation runs or is this a touchy-feely? How do you know it won't vapourize a nice big hole inside like the underground nuclear tests?

    "Of those that do reach our world, many would burn up in the atmosphere and pose no threat."
    More ifs.

    Sounds kind of flaky but he's got a $100K grant which I hope will answer these and good they are looking at *something*. I don't want to be an exhibit in a future sentient cockroach museum.
    • by Aryden ( 1872756 ) on Thursday May 30, 2013 @06:57AM (#43859025)
      It's this thing called physics and specifically, astrophysics. You break these roids up into smaller pieces. The gravity of nearby planets and the sun would have a far more drastic effect on the smaller pieces as well as the energy from the explosion modifying the trajectory of the pieces.
      • No, they wouldn't --- acceleration due to gravity is independent of the mass of the body. (The force due to gravity is GMm/r^2; acceleration is a=F/m; therefore the acceleration due to gravity is GMm/mr^2. The two m factors cancel out.)

        What would happen is the nuke would push the fragments apart. These would continue to diverge, but would follow much the same course as the original asteroid. Whether they've been deflected enough to miss the Earth --- which is, of course, a really big target --- depends enti
        • I'm no astrophysicist, but it seems to me that if you break the asteroid apart, and all the fragments still fall into Earth's atmosphere, a smaller mass of debris will strike the surface because more of it will vaporize in the atmosphere, due to greater surface area (of many fragments versus one single asteroid). Now whether that's enough to make a worthwhile difference, I dunno.

    • by gatkinso ( 15975 )

      I imagine the nuke shatters the asteroid, sending chunks flying, and Newton 2 then comes into play diverting the main body just enough to miss us.

    • Sounds kind of flaky but he's got a $100K grant...

      Come on, you gotta let people play with money in ways that are so slim to succeed that they'll need to ask for more to play with. It's how the aste.. err.. WORLD goes 'round.

      And also, maybe he'll get to play with a nuke or at least watch during a test. Everyone wants to do it!

      :-)

    • Two things:

      1. Doing nothing means much worse damage, if not extinction. Under those circumstances, I don't see why sending lots of nuclear ordinance would be a bad thing.

      2. Fragmenting a big rock means you get smaller rocks. Smaller objects that are fragments of one bigger object will have more surface area, which will mean more protection from atmospheric forces during entry. It also means less damage due to simple F = ma physics - reduce the mass, reduce the force to any specific area. I'd much rath

    • by Afty0r ( 263037 )

      To be fair, regardless of simulations, proofs etc. having 50 asteroids of mass 1 tonne each impacting the earth at the same time is *way* less risky than having a single asteroid of 50 tonnes impact - at the very least more of the mass will be burned off in the atmosphere, also the distributed nature, and lower individual impact energies, of the fragments will almost certainly result in less loss of life and less climate change...

    • A nudge I can understand if there is any way to create enough energy to push something that large out of the way, but what is the point of the nuke? How do we know this doesn't end up creating lots of smaller asteroids?

      That's specifically how it works. The idea is that lots of small pieces are less damaging than the big chunk, because each little chunk can burn on its own instead of one big chunk making it to the ground. A bunch of small pieces reaching the ground do less damage than one big chunk (something the size of a house hitting the ocean is a tsunami, something the size of a city is a shockwave, and so on) so busting it up reduces the total damage by a huge amount even if total deflection isn't possible.

      Hell of a bet to take on a hunch. Where are the simulation runs or is this a touchy-feely? How do you know it won't vapourize a nice big hole inside like the underground nuclear tests?

      Firstl

  • by maxwell demon ( 590494 ) on Thursday May 30, 2013 @05:22AM (#43858633) Journal

    Nuke it from orbit. It's the only way to be sure.

  • Asteroid Deflection Research Center at Iowa State University

    Meanwhile, my alma mater's big project is going to be a pork-barreled animal disease lab within eyesight of 50,000 respiratory tracts on gamedays. Ad Astra, my ass.

  • If the asteroid is spinning (as it surely must be) then this maneuver is much harder...
  • What sort of debris would actually find its way down?

    My first thought was "okay, send up hundreds or thousands of high explosive devices distributed evenly on the surface of the oncoming rock to form a giant shotgun blast to try to reduce one big thing into a whole bunch of small things which would burn up in the atmosphere.

    That might only blast away the surface of the rock leaving behind a large core of the original and a lot of debris particles, but you know? Lather, rinse, repeat as needed. And of cour

  • by gmuslera ( 3436 ) on Thursday May 30, 2013 @08:09AM (#43859641) Homepage Journal
    Even it works, it implies knowing in advance of at least 1 year that it is coming (and sometimes the time since notice is far shorter [nature.com], even if should be easier to spot bigger ones). Maybe with more of these [slashdot.org] we could improve detection rate before is too late.
  • by Noexit ( 107629 ) on Thursday May 30, 2013 @09:03AM (#43860189) Homepage

    Build a triangular shaped ship and just blast the asteroids into smaller chunks, then smaller pieces and then finally destroy them altogether.

  • by ChrisCampbell47 ( 181542 ) on Thursday May 30, 2013 @11:19AM (#43861951)

    Last month, the annual Planetary Defense Conference took place, this time in Flagstaff, Arizona (down the road from Meteor Crater). If you are interested in this topic, you really should take a look at the incredible video archive which has ALL of the presentations -- like 23 hours of them. Seriously, if you really want to dive deep into this subject, imagine me GRABBING YOUR SHOULDERS AND SHAKING YOU and saying loudly right into your face "watch these videos!"

    Here is the conference webpage:

    http://www.iaaconferences.org/pdc2013/ [iaaconferences.org]

    And here is the program, useful for navigating the video archive below:

    http://iaaweb.org/iaa/Scientific%20Activity/pdc2013program.pdf [iaaweb.org]

    But you really want to go to the videos. Here is the complete archive:

    http://www.livestream.com/pdc2013/folder [livestream.com]

    Particularly germane to the discussion here, check out this video which includes two presentations:

    http://www.livestream.com/pdc2013/video?clipId=pla_48629586-65d2-44c3-a1f3-57c0c259d526 [livestream.com]

    At the 1h21m point:
    Overview of Collisional-Threat Mitigation Activities at Lawrence Livermore National Laboratory
    Paul Miller
    (very dry delivery, but very interesting review of nuclear weapon solutions)

    At the 1h42m40s point:
    GPU Accelerated 3-D Modeling and Simulation of a Blended Kinetic Impact and Nuclear Subsurface Explosion
    Brian Kaplinger
    (new PhD, on the same team as Dr. Wie, the author mention in the post that leads this thread).

    These guys have thought about these problems far harder than you have. You might benefit from listening to them for 20 minutes.

    Or, you know, just skip this and resume your underinformed opinionating :)

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