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New Best Way To Nuke a Short-Notice Asteroid

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.'"

311 comments

  1. Love the way... by stoofa · · Score: 5, Funny

    ...his name is the sound his plan would make.

    Bong Wie!

    1. Re:Love the way... by Anonymous Coward · · Score: 0

      Yes, because "Explosions don't go 'boom' in a vacuum!"

    2. Re:Love the way... by Anonymous Coward · · Score: 1

      Bong Wie!

      I rather it be "Pong", just like the original video game

    3. Re:Love the way... by Intrepid+imaginaut · · Score: 1

      Sounds half Filipino, half Chinese. I know a few Bongs, a Cherry Pie, a Zip and a Bing.

    4. Re:Love the way... by Anonymous Coward · · Score: 1

      How about a Krystal Ball?... http://en.wikipedia.org/wiki/Krystal_Ball

    5. Re:Love the way... by rossdee · · Score: 1

      "and a Bing."

      Is that who the Micro$oft Search engine is named after? (Or was it the guy that sang White Christmas)

    6. Re:Love the way... by davester666 · · Score: 1

      What does 'doug141' sound like? Or 'samzenpus' for that matter?

      I don't think they sound like an explosion, other than the case of the explosion happening in a vacuum in space, so there is no sound, just as if you were standing on said asteroid without a helmet and tried to say their names.

      --
      Sleep your way to a whiter smile...date a dentist!
    7. Re:Love the way... by Tablizer · · Score: 1

      Love the way his name is the sound his plan would make...Bong Wie!

      Just keep his colleague, Aimee Wong, off the project.

    8. Re:Love the way... by Anonymous Coward · · Score: 0

      Yeah, I've know a few bongs in my time...

      But as far as names go theres Ping (that one's really popular), Pong (coincidentally), Ding, *don't forget* Dong (who doesn't love a good Dong, ameyrite?), Sunshine ... but my favorite is Gr (pronounced Grrr! Seriously, that is one of the absolute funnest names to say. A girl's name too, which makes it even more awesome. Genius! Hmong name - if you were curious).

      I want to name my next dog Grrr!

      (I love dogs, & that's not an insult at all)

  2. how short is the notice? by Swampash · · Score: 2

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

    1. Re:how short is the notice? by heypete · · Score: 5, Informative

      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.

    2. Re:how short is the notice? by Anonymous Coward · · Score: 4, Insightful

      If we're facing a potential wipe-out of several major coastal cities, I'm hoping we would get some leeway on expenses.

      Probably not though. :(
      I'm sure we would still be fighting over who would pay for it, or some other political bullshit when it hit and killed us all.

    3. Re:how short is the notice? by Anonymous Coward · · Score: 0

      Nonsense. You'd just use the asteroid *itself* as fuel.
      As long as it's not made of iron, you can always either use fusion or fission. Both of which being something we already did in bomb form. (Although of course we may not have the experience to do it with *all* materials *yet*. But I don't think any asteroid is *pure* iron.)

    4. Re:how short is the notice? by Salgak1 · · Score: 2

      Who needs fuel ? Send a nuclear-powered mass driver/excavator. Use the asteroidal itself as reaction mass. . . .

    5. Re:how short is the notice? by K.+S.+Kyosuke · · Score: 2

      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.

      --
      Ezekiel 23:20
    6. Re:how short is the notice? by K.+S.+Kyosuke · · Score: 4, Insightful

      Nonsense. You'd just use the asteroid *itself* as fuel.

      That's what the nuke does. The asteroid provides fuel (as in mass), and the nuke provides the energy.

      --
      Ezekiel 23:20
    7. Re:how short is the notice? by Charliemopps · · Score: 1

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

    8. Re:how short is the notice? by Charliemopps · · Score: 0

      We wont know what it's made of... but there's a high likelihood it'll be solid iron. We don't have anything that can penetrate 15 meters of solid iron in-tact.

    9. Re:how short is the notice? by firex726 · · Score: 1

      Well think about how much fuel was used for the shuttle. Shuttle was around 165,000 Lbs empty; but adding in the fuel and external tanks/boosters we're looking at a whopping 4.4 Million Lbs that needs to get off the ground.

      Now compare that to the Chicxulub meteorite that killed the Dinosaurs, it was 10 Km in diameter; pretty sure it'll take a bit more fuel to divert something like that.

    10. Re:how short is the notice? by K.+S.+Kyosuke · · Score: 4, Informative

      I believe we're quite capable of telling the composition from remote observation and adjusting the plan accordingly. Also, some M-type asteroids (such as 16 Psyche, to name the most notorious example) do have significant quantities of iron, but I don't think that the majority of even the metallic M-type asteroids are solid iron. "High likelihood" is really an exaggeration.

      --
      Ezekiel 23:20
    11. Re:how short is the notice? by alexander_686 · · Score: 2

      No, there is no easy way.

      We can tell what is on the outside, we can tell the approximate mass, but after that...
      We can't tell if it is solid. I would actually be a little surprised it was sold.
                It could be a couple of small asteroids glued together with ice to make 1 large one. See Comet Shoemaker–Levy 9.
                It could be a lot of gravel bonded together with a lot of ice.

      If this was done close to Earth, it just might shatter and not be deflected – sort of being hit with a shotgun blast instead of a bullet.

    12. Re:how short is the notice? by Anonymous Coward · · Score: 0

      if it shattered and then entered the atmosphere, that would still be good, because the small pieces would burn up in the atmosphere.

    13. Re:how short is the notice? by OakDragon · · Score: 1

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

      But that would be boring.

    14. Re:how short is the notice? by lister+king+of+smeg · · Score: 3, Insightful

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

      I believe the official Protocol involves bending over and kissing your ass goodbye

      --
      ---Saying gnome 3 is better than windows 8 not so much a compliment as it is damning with light praise.
    15. Re:how short is the notice? by Anonymous Coward · · Score: 0

      You could also listen to Scott Manley talk about what it would take to deorbit a moon.

      www.youtube.com/watch?v=G01NoaTM46o

    16. Re:how short is the notice? by Anonymous Coward · · Score: 0

      yes, that worked so well for shoemaker levee.

      gravity shattered it, and then jupiter got earth size pock marks from each one.

    17. Re:how short is the notice? by AchilleTalon · · Score: 1

      Who cares? The device must be built and operational well before any asteroid is on reach of it. This device must already be designed for such a scenario.

      --
      Achille Talon
      Hop!
    18. Re:how short is the notice? by Megane · · Score: 1

      And the hole (hopefully) provides the direction in which the energy pushes the asteroid.

      --
      #naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
    19. Re:how short is the notice? by geekoid · · Score: 2

      AH, so we will completely invent. build, launch and attach this new device in a few months, will we?

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    20. Re:how short is the notice? by geekoid · · Score: 1

      Which is still better. A lot of little masses are better then one huge one.
      The energy is dissipated over a wider area, and it has more surface area exposed, so more of the mass will 'burn up' in the atmosphere.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    21. Re:how short is the notice? by geekoid · · Score: 1

      Another quitter.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    22. Re:how short is the notice? by drinkypoo · · Score: 3, Insightful

      Once again, this is for a short-notice event. Landing is hard, it takes a lot of energy. Crashing is easy, sometimes it happens when you're trying to land. Better to plan to crash.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    23. Re:how short is the notice? by neonKow · · Score: 1, Insightful

      While we're using made-up science far beyond the realm of our technology, why not just open a warp tunnel near the asteroid and teleport the thing somewhere safer?

    24. Re:how short is the notice? by jedidiah · · Score: 1

      As far as the hole goes, you would think that a conventional bunker buster with a nuke chaser would be the way to go.

      It would capture all of the basic elements of the plan from Armageddon without the need to land a bunch of roughnecks in space suits on an a rock flying through space.

      --
      A Pirate and a Puritan look the same on a balance sheet.
    25. Re:how short is the notice? by Charliemopps · · Score: 1

      Even if only 5% of them are, my points still valid. Our "hardened nukes" are designed for dirt and concrete bunkers that are only a few feet or meters think. The weakest asteroids we're going to find are going to be mostly ice. Ice that's been ice for millions of years. It's going to make concrete look like marshmallow fluff. Add to that the fact that a missile headed at a target in space is going to be moving exponentially faster than anything we have on earth and you have yourself an impact that is not survivable by any technology we'll see in the near future.

    26. Re:how short is the notice? by Anonymous Coward · · Score: 1

      We are still looking for a free market solution.

    27. Re:how short is the notice? by cusco · · Score: 2

      I'm not so sure which is worse, a single million-ton impact, or a million 1-ton air bursts. I had a meteorology instructor say, "Take the Earth and shrink it down to the size of a basketball. The bumps are higher than Everest, the cracks are deeper than the Challenger deep, but it will do for our example. Now dunk it under water and take it back out. That sheen of water on the surface? That's actually thicker than our breathable atmosphere." Now imagine a million grains of sand spread across the surface of that sheen of water. Are you sure that's better?

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    28. Re:how short is the notice? by Anonymous Coward · · Score: 0

      yeah.. At that size even if we were able to pulverize it into dust we'd still have that much dust and heat being dumped into our atmosphere.

    29. Re:how short is the notice? by Arrogant+Monkey · · Score: 1

      | If this was done close to Earth, it just might shatter and not be deflected – sort of being hit with a shotgun blast instead of a bullet. But wouldn't the fragments have a higher likelihood of burning up in re-entry? Yes that will add tons of vaporized debris to the atmosphere and a lot of friction heat, but the Earth's a pretty big place - wouldn't that just be noise by comparison with a large multiton single block of rock/iron/ice hitting us and not being burnt up?

    30. Re:how short is the notice? by cusco · · Score: 1

      Replying to myself, I know. Forgot to mention that one of the issues generally ignored in the "airburst vs impact" debate is that in an impact case a large portion of the kinetic energy is going to be absorbed by the ground, sending out shock waves and heating rock and water rather than heating up the atmosphere. Those are mostly localized effects rather than widespread weather/climate changing ones.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    31. Re:how short is the notice? by tinkerton · · Score: 1

      It's going to make concrete look like marshmallow fluff.

      You mean, the bunker busters are going to make ice look like marshmallow fluff?

    32. Re:how short is the notice? by tinkerton · · Score: 1

      I think it requires some modeling, and maybe that's what the writer actually did. you take asteroids of different sizes and materials, and estimate the resulting distribution of fragment sizes. Now this buckshot technique is going to make sure the planet will be hit, but the fragments will be smaller, and many fragments will miss the earth. You don't need that much mass to wipe out a city,something like a 100m asteroid,

      For a 100m diameter asteroid nuking it could be sensible. In principle you could make 8 50m fragments out of one 100m one, but it would require a very smart nuke. Another type of very smart nuke would create many fragments of a few meters so they would all burn up before they reach the ground.

      In practice you might actually make things much worse for a sizable asteroid. A smart nuke can make many 100m asteroids out of one 500m asteroid.

      There has always been a lack of killing efficiency in something like the tsar bomba.

    33. Re:how short is the notice? by OolimPhon · · Score: 1

      Replying to myself, I know. Forgot to mention that one of the issues generally ignored in the "airburst vs impact" debate is that in an impact case a large portion of the kinetic energy is going to be absorbed by the ground, sending out shock waves and heating rock and water rather than heating up the atmosphere. Those are mostly localized effects rather than widespread weather/climate changing ones.

      Unless you happen to live on the other side of the planet, of course. There is a plausible theory that the shock waves from the Chixulub impact merged together 180 degrees around the planet and caused the Deccan Traps. 10,000 years of volcanoes, anyone?

    34. Re:how short is the notice? by Anonymous Coward · · Score: 0

      But it's already in space? So, couldn't you deflect something with less effort than achieving escape velocity?

    35. Re:how short is the notice? by Anonymous Coward · · Score: 0

      For astronomically expensive items you have to think beyond the dollar amounts and accountants. For a project of this scale you'd need to reallocate large amounts of resources from other areas. Which would you rather do without for a few years? Public school? Police and prison guards? Have the world's militaries pinky promise to not attack during a furlow? Eliminate welfare, subsidized healthcare, or foreign aid? Obviously it would be done, but ultimately money is exchangeable for life (in both quantity and quality), so it's a cost-benefit analysis. How many people suffer & die if we let the meteor hit VS how many suffer & die from the economic ramifications of averting it?

    36. Re:how short is the notice? by alexander_686 · · Score: 1

      Maybe yes, maybe no. To many variables would change.

      Do you get thousands of small chunks or a half dozen big chunks? If thousands of small chunks, then yes, it would most burn up in the atmosphere. Lots of air burst, lots of stuff dumped into the atmosphere but probably the best case scenario. On the other hand, if it just shattered into a few chunks....

      I have seen arguments on which one is worse, land based strikes, water strikes, or air burst. You would get all 3.

      One could get general damage to the entire world instead of concentrating the damage in a single place. If it were a water strike with an asteroid, you would get 1 massive tilde wave that would strike one ocean. With multiple strides you could get massive tilde waves in multiple oceans.

    37. Re:how short is the notice? by R3d+M3rcury · · Score: 1

      I'm sure we would still be fighting over who would pay for it, or some other political bullshit when it hit and killed us all.

      True. But some of us would go to Heaven while the rest of you evil people would end up suffering eternal torment and damnation in Hell.

      So why the hell should my tax dollars go to saving the lives of a bunch of sinners? Let the end times come! It's God's Will!

      (No, I don't believe this. The scary thing is, there are those who do.)

    38. Re:how short is the notice? by Runaway1956 · · Score: 1

      That is my thought. An "impactor" would seem to leave a nice wide crater. A bunker buster would probably leave a cleaner, more focused channel, and probably deeper. Slip the nuke down into the deep, narrow hole, detonate, the plasma is more or less focused in one direction. Any chunks and pieces that break away are just reaction mass anyway. The asteroid may or may not be fragmented, but it will have a lot of delta-V in the desired direction.

      --
      "Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
    39. Re:how short is the notice? by Runaway1956 · · Score: 1

      "I would actually be a little surprised it was sold."

      They'll buy ANYTHING on E-bay. No reason to be surprised.

      --
      "Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
    40. Re:how short is the notice? by Anonymous Coward · · Score: 0

      It worked when SG-1 did it.

    41. Re:how short is the notice? by Anonymous Coward · · Score: 0

      Still depends on the size threshold and where it's heading. Might be better to have a lot of smaller objects with a high surface area where most of which may burn up in the atmosphere than one large chunck that is guaranteed to mess up a city. Of course if the asteroid is big enough where the majority of pieces are still likely to make a mess, then you're pretty much up shit creek anyways.

    42. Re:how short is the notice? by firex726 · · Score: 1

      Sure... but the fuel is here on Earth.
      Rocket Engines are not that efficient, you still need a good bit of fuel to effect a course change. You could use something like an Ion Engine; but you'd need to do it for a long ass time; which is the problem here. If we only know about it for a year before impact we'd need a crap ton of force to change it's orbit.

    43. Re:how short is the notice? by tibman · · Score: 1

      Modern bunker busters can penetrate 10meters of reinforced concrete. You'd be surprised how tough these things are. Some are thousands of kilograms of just metal shell and only 250 kg explosive inside. Some have counters inside that count how many floors the bomb has moved through so that it can detonate on a specific level of the bunker.

      I'd say reinforced concrete is tougher than ice too.

      --
      http://soylentnews.org/~tibman
    44. Re:how short is the notice? by cusco · · Score: 1

      Less than ten percent of asteroids are metallic. The vast majority are "stony", which may vary from a big chunk of solid rock to a rubble pile barely held together by gravity.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    45. Re:how short is the notice? by RockDoctor · · Score: 1

      A lot of little masses are better then one huge one. The energy is dissipated over a wider area, and it has more surface area exposed, so more of the mass will 'burn up' in the atmosphere.

      Please feel free to carry out the experiments necessary to validate your theory, but using a planet that doesn't have all the known life in the universe on it.

      I wouldn't particularly object to you doing it using the Moon. But you'd need to put an atmosphere on it first. Enjoy fixing that.

      Ha ha, but serious. Let's practice steering asteroids, and blowing them up, using Venus as a target. Then we'll have two potentially capable technologies for our protection, and some real experimental evidence on which one is harder or faster to do, and which one is the more destructive in the event of incomplete success.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    46. Re:how short is the notice? by RockDoctor · · Score: 1

      There is a plausible theory

      Plausible to you. None of my geologist colleagues who have thought about it rate the theory.

      that the shock waves from the Chixulub impact merged together 180 degrees around the planet and caused the Deccan Traps. 10,000 years of volcanoes, anyone?

      More like half- to three-quarters of a million years. And the rate would be on the order of a Pinatubo every few years to a Laki every century or so. Most of the dinosaurs probably never knew that anything was hitting them. Until Chixulub, and then they had 200,000 to 300,000 years to think about it before dying out. Say, a couple of hundred generations. The length of time since humans invented/ discovered agriculture, in terms of human generations.

      Most people don't "get" geological time. Which is fine by me : keeps me in employment.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  3. Armageddon by prasadsurve · · Score: 0

    Or we could have Bruce Willis and his team dig a hole to put the nuke in.

    1. Re:Armageddon by Anonymous Coward · · Score: 1

      Only if we can leave him there. Sadly however, it only might prevent him from doing another 'die hard' sequel.

    2. Re:Armageddon by Anonymous Coward · · Score: 0

      That was my first thought: wasn't there a movie about this? You know science is clueless when it starts immitating Hollywood. Maybe they should send Lindsey Lohan. She needs to get away from here anyway.

    3. Re:Armageddon by Calydor · · Score: 2

      Really?

      I beg of you, try going through science fiction dating all the way back to Jules Verne. Space rockets? Submarines? He 'invented' those in his books. More recently, Star Trek's communicators? You've got those in the shape of cell phones.

      Science isn't clueless when it imitates Hollywood or any other kind of fiction. It is inspired by it.

      --
      -=This sig has nothing to do with my comment. Move along now=-
    4. Re:Armageddon by ichthyoboy · · Score: 2

      You say that like it's a bad thing....

    5. Re:Armageddon by OakDragon · · Score: 1

      Hey! I'm still hoping one of the next 4 "Die Hard"s will be good!

    6. Re:Armageddon by Anonymous Coward · · Score: 1

      Only if we can leave him there.

      This will also give us an excuse to nuke the asteroid after it has passed the earth.

    7. Re:Armageddon by geekoid · · Score: 2

      Not really.
      They deal with the same problem, so sometime they seem similar. Of course, people ignore the misses(majority of sci-fi) and the details.

      How do you move underwater? why you create a sealed boat the goes underwater. a 'Sub' marine, if you will. A concept far older the Jules Vern.
      Going into space? ;also older the Verne. The shape of his fiction device was slightly different then previous ideas. We where in the age of science, so he made it science. 3000 years early it might just as well been God dust.

      How to do create a walkie talkie that can also fit in you'r pocket? you have it fold in half. Do you think the communicate was the first devices to fold enough to fit someplace?
      The communicate is not a cell phone, never acted like a cell phone, doesn't have the capabilities of a cell phone, but lets say they invented it. sheesh.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    8. Re:Armageddon by Shotgun · · Score: 1

      You really think Bruce Willis will live that long? Or that they'll continue to create "Die Hard" puns?

      --
      Aah, change is good. -- Rafiki
      Yeah, but it ain't easy. -- Simba
    9. Re:Armageddon by RockDoctor · · Score: 1

      You really think Bruce Willis will live that long?

      Or that they've got enough video in the can already that they can completely replace live-action-Bruce with computer-generated-Bruce, and nobody will be able to tell the difference?

      Or, perhaps they already did?

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  4. Sheesh... by Anonymous Coward · · Score: 0

    Will this be in time for the one coming near us on the 31st?

    1. Re:Sheesh... by Mike+Frett · · Score: 1

      1998 QE2 will be about 3 Million miles away. I think we're pretty safe, no Nukes needed. =)

    2. Re:Sheesh... by peragrin · · Score: 4, Interesting

      But if we fired off two or three hundred nukes we can claim those as part of the disarming campaign, test them in live fire conditions, increase the exposure of space travel to people, and watch a bunch of real big light shows.

      that is like 5 wins.

      --
      i thought once I was found, but it was only a dream.
    3. Re:Sheesh... by Askmum · · Score: 1

      1998 QE2 will be about 3 Million miles away. I think we're pretty safe, no Nukes needed. =)

      How about 1969 QE2 then. Reportedly that's a lot closer already.

    4. Re:Sheesh... by Grizzley9 · · Score: 3, Interesting

      1998 QE2 will be about 3 Million miles away. I think we're pretty safe, no Nukes needed. =)

      Wouldn't that make for a good test case though? I'd hope our first attempt at deflecting an asteroid isn't our one shot at survival. With it being so far away you could do a test on it and gather some valuable data.

    5. Re:Sheesh... by Anonymous Coward · · Score: 0

      Actually, if the orbit is very excentric, it can be spiralling down to earth and it will be on your doorstep before you know it.

    6. Re:Sheesh... by Anonymous Coward · · Score: 0

      Hopefully such a test would be done after it passes our planet. I could just see it now: scientists learn they can't predict how nukes affect an asteroid's trajectory when they turn a near miss into a direct hit.

    7. Re:Sheesh... by RockDoctor · · Score: 1

      and watch a bunch of real big light shows.

      Ummm, light intensity of a megaton bomb at 3 million miles range ...

      To back-of-the-envelope calculate that, I could look for light intensity figures. But why? I can use inverse-square. A megaton at 3 million miles range will have a certain intensity; so at half the range, you'd need a quarter of the tonnage to get the same effect. Quick spreadsheet fat-fingering and ... when the tonnage gets down to about a kilogramme (remember that the yield is initially in tonnes of TNT equivalent, and it's an energy release ; it doesn't really matter if it's nuclear, chemical, or kinetic energy) you're at a range of ... I make it about 91 miles. Thinking of the Mythbuster's explosive orgasms, would that be visible at 91 miles?

      Bring the range down to a metre or so ... and you're looking at in the order of 1/20th gramme of TNT equivalent. Which is in the ballpark of a drop of water. You'd see it. If it were TNT un-contained on a bench when it detonated at that range, I'd wear safety spectacles. But not sun glasses.

      Yeah, I guess it would give a light show in the same sort of intensity range as conventional fireworks. Maybe a bit brighter. One flash.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  5. But Why? by MichaelSmith · · Score: 2

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

    1. Re:But Why? by Metabolife · · Score: 5, Funny

      Pack your bags kids! We're going to the moon!

    2. Re:But Why? by Verunks · · Score: 4, Insightful

      because it's less expensive than rebuild a city?

    3. Re:But Why? by MacGyver2210 · · Score: 4, Insightful

      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.

      --
      If the only way you can accept an assertion is by faith, then you are conceding that it can't be taken on its own merits
    4. Re:But Why? by hcs_$reboot · · Score: 1

      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..

      --
      Slashdot, fix the reply notifications... You won't get away with it...
    5. Re:But Why? by Anonymous Coward · · Score: 0

      Actually if you break a large object into many small objects the pieces still have the same total kinetic energy. It turns out that distributing the energy over a larger area is actually worse as while each place may be slightly better off it will still be uninhabitable (assuming a large asteroid), but there will be fewer areas sufficiently far from an impact to be unaffected.

    6. Re: But Why? by AvitarX · · Score: 1

      Does surface area to volume ratio not come into play?

      --
      Wow, sent an e-mail as suggested when clicking on "use classic" banner, and got a fast response that addressed my msg
    7. Re:But Why? by xelah · · Score: 1

      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.

    8. Re:But Why? by Anonymous Coward · · Score: 5, Funny

      Yes, but by breaking it into smaller chunks you are increasing the surface area of the impactor. Its mass obviously stays the same, so the surface area/mass ratio changes in your favour, which means more of the asteroid will get burned up in the atmosphere before hitting the Earth's surface. Of course it depends just how many bits you can smash it into as to whether or not this will be worthwhile.

      Try it with ice cubes - fill two identical ice-cream tubs with water and freeze them. Smash one into bits (you don't need a nuclear warhead for this, but if you decide to use one please post a video on youtube) and put all the bits in a tray. Put the intact ice-lump onto a second tray and leave them side-by-side in the sun. See which one completely melts away first. Same amount of water, different mass/surface area ratios.

    9. Re:But Why? by Anonymous Coward · · Score: 0

      The trajectory of the fragments would diverge so they would end up missing us. That's the whole point. Any which do come our way may burn up anyway.

    10. Re:But Why? by K.+S.+Kyosuke · · Score: 3, Insightful

      Letting it wipe out all life completely is the cheapest option at all - you don't spend a cent on rebuilding anything. :-)

      --
      Ezekiel 23:20
    11. Re:But Why? by K.+S.+Kyosuke · · Score: 2

      Perturbation analysis, my friend. Despite the fact that the total energy will change very little, if it breaks up, most of the pieces will be unlikely to hit a single compact object - dispersion of their trajectories in the phase space. Picture a shotgun hitting you with only two smallish pellets rather then with all of them.

      --
      Ezekiel 23:20
    12. Re:But Why? by K.+S.+Kyosuke · · Score: 0

      Its mass obviously stays the same, so the surface area/mass ratio changes in your favour, which means more of the asteroid will get burned up in the atmosphere before hitting the Earth's surface.

      Merely breaking it into pieces does not matter all that much, because it still gives off its kinetic energy and the results could be nasty anyway. For example, the Tunguska asteroid probably disintegrated in an airburst and gave off most of its energy some eight kilometers above the ground. You really don't need for that thing to hit the ground at high velocity.

      --
      Ezekiel 23:20
    13. Re:But Why? by Aryden · · Score: 1

      2 things:
      1) Smaller chunks would have a slightly different trajectory so that some would miss us entirely while others, being much smaller, would burn up in the atmosphere before their kinetic energy would reach a point to harm us.
      2) Exploding 1 incredibly large roid in the the lower atmosphere would have the effect you are describing, but by breaking it up, the mass of the particles entering the lower atmosphere would be drastically smaller. Thus, creating less "dust cloud".

    14. Re:But Why? by stenvar · · Score: 1

      Your nuke may not be strong enough to deflect the asteroid, but it may be strong enough to increase the area over which the pieces get dispersed many times, resulting in a much lower energy per area.

    15. Re:But Why? by Anonymous Coward · · Score: 0

      I guess it will heavily depend on the asteroid. Remember that a nuclear explosion is not that big. Without an atmospheric shock wave by suddenly heated air and with an asteroid not that scared about radioactivity, for many asteroids a nuclear bomb might have hardly any effect. If it has an effect it might disperse it a bit but garvity might still keep it together (and it it is not done far enough away, even if it get a dissolving cloud of debris, that cloud might not be that big once it reaches earth).

      So instead of a single impact, which with a small object would otherwise only destroy a small area and only have a effect if you are very very very unlucky that it is a city you'd get a large cloud that could inconvenience a larger area.

      And if the asteroid is big enough to have a global effect, then having the whole earth atmosphere hit with enough material to burn much more than some little eject material from an impact can cause.

      Would you rather get hit with a single bullet that has a chance to hit nothing important, or getting a load of shrapnel hitting your full body?

      Or even more: would you rather be hit a by a 500g package of flour or by a cloud of flour nicely dispersed? What if someone put some flames before you?

      Captcha: crossing

    16. Re:But Why? by K.+S.+Kyosuke · · Score: 1

      1) Smaller chunks would have a slightly different trajectory so that some would miss us entirely while others, being much smaller, would burn up in the atmosphere before their kinetic energy would reach a point to harm us.

      You are reiterating what I had already said somewhere else in this discussion.

      but by breaking it up, the mass of the particles entering the lower atmosphere would be drastically smaller.

      That is true, but it really doesn't matter all that much if 1.0e9 tons hit you in the form of a few large fragments or a million small ones. The energy is still the same (you can do basic arithmetics, can you?), and, e.g., the production of toxic nitrogen oxides from the atmosphere heating wouldn't be significantly diminished, especially if all the asteroid fragment energy is expended in the atmosphere rather than in a single impact site. The former effect you're mentioning (as well as I did) is much more important.

      --
      Ezekiel 23:20
    17. Re:But Why? by K.+S.+Kyosuke · · Score: 1

      Your nuke may not be strong enough to deflect the asteroid, but it may be strong enough to increase the area over which the pieces get dispersed many times

      There's a continuum between these two. And yes, I'm aware of how basic physics works.

      --
      Ezekiel 23:20
    18. Re:But Why? by necro81 · · Score: 1

      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 through the atmosphere during entry is not as deterministic as much larger objects. And there's no guarantee that it'll make it all the way to the ground - you may well end up with an airburst, like in Chelyabinsk. So the size of the evacuation area would be huge: hundreds of square kilometers, and could affect millions of people. The costs of doing that kind of evacuation would also be enormous.

      But who says you can't do both: prudence counsels that you try to damage/disrupt/avoid the threat in the first place, while also making preparations for what to do if that fails.

    19. Re:But Why? by hattig · · Score: 3, Interesting

      I still prefer the odds on the broken up asteroid than the guaranteed end of human life full asteroid.

      In addition it could be that many of the pieces will miss us anyway. The relative speed of the asteroid to earth could be as high as 70km/s, so if we hit it with 24 hours to go, that's 86400 seconds for each piece to shear away from us from a distance of 6 million km. We only need to change the asteroid piece trajectory slightly to make it miss the Earth entirely. Indeed it may be prudent to have a second warhead to explode after the first one to give the pieces more momentum away from the line of impact (we'd need around 100m/s, that's a lot of momentum to be giving to potentially massive lumps of rocky iron).

    20. Re:But Why? by Aryden · · Score: 1

      But it's not 1.0e9 tons hitting you in the fragmented instance. You're reasoning is that you explode the roid but all of the chunks still hit you when in reality, you would explode the roid and X chunks miss you entirely while Y chunks actually impact the atmosphere.

      If you break a roid of 1.0e9 MT into 1000 smaller chunks, changing the trajectory of even 20% of the chunks such that they miss you entirely, you are reducing your impact mass by 200 million MT. That's a fairly significant number. This represents only what misses us entirely, not what would "skip" off the upper atmosphere.

      Additionally, small pockets of gas/dust would settle and dissipate much faster than 1 very large pocket.

      Also, you are removing the effect of the large mass impacting a single area creating either a tidal wave on an oceanic impact, or a massive dust cloud on a land impact.

    21. Re:But Why? by Anonymous Coward · · Score: 0

      Letting it wipe out all life completely is the cheapest option at all - you don't spend a cent on rebuilding anything. :-)

      That's the teabagger plan

    22. Re:But Why? by Anonymous Coward · · Score: 0

      ...and what if they don't? Radioactive fragments falling from the sky? Where do I sign up to live next to that? As per usual it doesn't sound like we're really thinking this through.

    23. Re:But Why? by MachineShedFred · · Score: 1

      Also, breaking it up dramatically increases the surface area being affected by atmospheric entry forces. More is going to burn up, and more pieces are going to break off and go away during entry.

      --
      Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
    24. Re:But Why? by K.+S.+Kyosuke · · Score: 0

      You're reasoning is that you explode the roid but all of the chunks still hit you when in reality, you would explode the roid and X chunks miss you entirely while Y chunks actually impact the atmosphere.

      You do have at least some reading comprehension, do you? First, I was responding to a specific comment where I pointed out that merely fragmenting the mass doesn't help you much, said comment completely ignoring the dispersion issue. Second, I'm aware of what you're referring to, I've already pointed it out somewhere else and I've even pointed it out to you explicitely that I had done that, with you completely ignoring my reminder. I'm really not sure how to get my message accross to you. (Perhaps you would like a Chinese translation?)

      --
      Ezekiel 23:20
    25. Re:But Why? by T.E.D. · · Score: 4, Insightful

      Actually if you break a large object into many small objects the pieces still have the same total kinetic energy.

      It isn't the kinetic energy in space that's the problem. The problem is the kinetic energy at point of impact with the earth's surface.

      If you spread that same energy out over hundreds (or perhaps thousands) of miles instead of one small impact crater, there is a very real qualatative difference. Not to mention the fact that the more surface area per mass an object has, the more of it will burn up in the atmosphere (further disspating the kinetic energy it had in space). Small objects tend to burn up completely.

      Think about it this way: Would your property fare better in a hailstorm with thousands of pea-sized hailstones hitting your yard, or just one large hailstone with the same total mass?

    26. Re:But Why? by wagnerrp · · Score: 2

      but by breaking it up, the mass of the particles entering the lower atmosphere would be drastically smaller.

      That is true, but it really doesn't matter all that much if 1.0e9 tons hit you in the form of a few large fragments or a million small ones. The energy is still the same (you can do basic arithmetics, can you?), and, e.g., the production of toxic nitrogen oxides from the atmosphere heating wouldn't be significantly diminished, especially if all the asteroid fragment energy is expended in the atmosphere rather than in a single impact site. The former effect you're mentioning (as well as I did) is much more important.

      Of course it matters. The energy from the Tunguska airburst is estimated to be as high as 130PJ. The largest thermonuclear detonation, the Tsar Bomba, was 210PJ. The Earth receives around 440PJ of sunlight every second of every day. Even your ten megaton asteroid traveling at 30km/s only amounts to about 9EJ, or roughly twenty seconds worth of sunlight. The energy from an asteroid impact isn't even a drop in the bucket in the grand scheme of things. The power density is what matters, the peak amplitude of that shock wave. If you have a single, large chunk, you're going to have a single large airburst and a massive amount of localized damage, or a large crater that spews large amounts of particulate into the atmosphere causing global weather shifts. If you break that up into thousands of little chunks, those are still going to cause a lot of damage, but now you have a dozen cities on fire, rather than one region completely wiped off the map and a dust cloud that drops you into a new ice age. It's a terrible disaster, but it's no longer an extinction level event.

    27. Re:But Why? by wagnerrp · · Score: 1

      One gigaton, not ten megaton, but energy scales linearly with mass, so it's 2000 seconds, or still only about half an hour worth of sunlight.

    28. Re:But Why? by NemoinSpace · · Score: 1

      I submit, being shot with a bullet made from lead or uranium does not effect the outcome in a statisticaly significant way. Silver being the exception, for vampires.

    29. Re:But Why? by K.+S.+Kyosuke · · Score: 3, Insightful

      I guess it will heavily depend on the asteroid.

      Most certainly. No objection here.

      Remember that a nuclear explosion is not that big. Without an atmospheric shock wave by suddenly heated air and with an asteroid not that scared about radioactivity, for many asteroids a nuclear bomb might have hardly any effect.

      I'd disagree here. With a moderately underground burst, a substantial mass of the asteroid (compared to the mass of the nuke - not compared to the mass of the asteroid, of course!) gets vaporized. Please remember that this is the mode in which a nuke airburst creates a fireball: The air is heated into incandescence by an extreme flux of X-ray radiation. In solid matter, the exponential falloff of the X-rays happens over a smaller distance, but you still evaporate a lot.

      If you do it on the surface or a few meters underground, you'll probably waste a lot of the energy. You'll get a lot of high temperature plasma, but the mass will be still quite low. What you should be aiming for (pun intended :-)) is a detonation depth sufficient to create a substantial mass of solid ejecta propelled by the explosion in (mostly) one direction such that their speed won't exceed some reasonble value (between 10-50 m/s?). Remember; you're aiming for maximum impulse, not for a high-speed jet. The remaining mass of the asteroid will receive the same impulse in the opposite direction.

      If it has an effect it might disperse it a bit but garvity might still keep it together

      The escape velocity of any small asteroid is minimal. You could jump with just your legs off of a 20km body and get lost in space just fine.

      --
      Ezekiel 23:20
    30. Re:But Why? by Aryden · · Score: 1

      didn't search your uName while reading from my phone while driving. I apologize for missing your previous statement.

    31. Re:But Why? by K.+S.+Kyosuke · · Score: 2

      reading from my phone while driving

      I suggest you delay any communication while driving. This may be dangerous to you and others.

      --
      Ezekiel 23:20
    32. Re:But Why? by Prof.Phreak · · Score: 1

      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.)

      --

      "If anything can go wrong, it will." - Murphy

    33. Re:But Why? by K.+S.+Kyosuke · · Score: 1

      If you have a single, large chunk, you're going to have a single large airburst

      Please keep ind mind that a single large fragment is not what I had in mind. I've assumed that by exploding the nuke, the mass is already fragmented into significantly smaller pieces (around the size of the Tunguska meteoroid, or not significantly larger), and I was contrasting it with what I understood to be the "drastically smaller" pieces the GGGP was talking about, and their environmental impact compared to the Tunguska-sized pieces. A single massive ground impact is obviously going to cause entirely different problems, especially if it hits the ocean.

      (This also completely omits the issue that the impact mass after detonating the nuke will be diminished because most of the fragments aren't going to hit us at all.)

      --
      Ezekiel 23:20
    34. Re:But Why? by K.+S.+Kyosuke · · Score: 1

      The former option is the intended result of the whole scenario, with the individual pieces travelling along their own trajectories in the phase space. If the breakup *doesn't* succeed, the remaining major part of the body will have been deflected with a predictable impulse (opposite the impuls imparted to the minor ejecta) and therefore won't be a threat. This means that both outcomes are essentilly fortuitous. The numbers you're mentioning are, unfortunately, too non-specific to judge it in any way. But you can write yourself a simulator for that (to get more concrete numbers). I think I did that a decade ago or so. I don't remember the results anymore, but it was quite fun. (Actually, celestial mechanics is quite fun on its own.)

      --
      Ezekiel 23:20
    35. Re:But Why? by Anonymous Coward · · Score: 0

      If the asteroid is big enough (diameter ~10 km; mountain-size), there's enough kinetic energy to heat the whole atmosphere to several hundred degrees.

    36. Re:But Why? by iainr · · Score: 1

      No no, I can suggest some really great roads for reading/posting whilst driving...some of the ones round Lashkar Gah are ideal for that kind of thing.

    37. Re:But Why? by Anonymous Coward · · Score: 0

      why is everyone talking extinction level asteroids? aren't we only worried about smaller ones that we somehow missed? with all of our detectors/sensors/whatnots scanning space continously for asteroids, i'm pretty sure any big enough to cause extinction would be caught long before we need to worry about this "short notice" proposal.

    38. Re:But Why? by onyxruby · · Score: 1

      The locale where it would hit is probably not feasible to evacuate. Pick a spot on earth that would be affected, middle of Africa, major city, farmland, doesn't matter. Now, propose a plan on how to evacuate that area that will work in the real world. Start by looking at examples of 'mandatory' evacuations in recent history for hurricanes, volcanoes, wild fires and the like. Point being that evacuations only work in the movies and even then they rarely work as they should. Evacuation also doesn't do anything for atmospheric affects, and those are what are said to kill most of the dinosaurs.

      You have to either destroy it or deflect it, those are the only realistic choices. If you destroy it you have many small pieces that impact in a series of impacts instead of all at once. Most of the smaller pieces will simply burn up in the atmosphere. The larger pieces may or may not hit the earth (some will maintain trajectory, many will be deflected out of the way). Those pieces that do hit will still cause damage, however they have far less mass.

      To put in perspective the earth gets hit by small amounts of material every day and most people never notice. To quote NASA "Every day, the Earth is bombarded with more than 100 tons of dust and sand-size particles." If those same 100 tons of debris hit as a single asteroid the damage would be quite devastating. By spreading out the impact into a series of smaller impacts you reduce the damage that would occur.

    39. Re:But Why? by Anonymous Coward · · Score: 0

      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.

      Holy fucking shit there are people so fucking stupid here that they get their science from that fucked up movie.

      Hint asshole: Chances are we won't even know if the 'roid is a solid mass till it gets very close. Giving it the old one two with an impactor and nuke may just vaporize the fucker and give us a pelting that covers the whole planet. Same nuclear winter....thousands of impacts large enough to wipe out whole cities. Fucking clever hey?

      Go take a look at some actual asteroid science instead of watching Hollywood and pretending life is really like that.

    40. Re:But Why? by stenvar · · Score: 1

      There's a continuum between these two. And yes, I'm aware of how basic physics works.

      Apparently not, otherwise you wouldn't have claimed that it "didn't matter much".

    41. Re:But Why? by Will.Woodhull · · Score: 1

      The way I read TFA, the point is very much to decrease the amount of mass that impacts the Earth. In the best case, the nuclear detonation creates a jet of ejecta that deflects the asteroid to a non-collision orbit. In the more likely case, the ejecta sprays outward with enough velocity that much of the original mass misses the Earth completely. In between there are various grazing impacts where the Earth is peppered by some of the ejecta, or the main body enters and leaves the atmosphere without contacting the lithosphere, etc. This assumes the asteroid can be hit while it is still several weeks away-- which is likely, given our increasing ability to spot this kind of threat.

      The concept is sound enough that it should be investigated further. Whether it makes sense to deploy an asteroid busting system is a decision best made later, after the concept is better defined and more is known about the structure of asteroids and how they are likely to react to a thermonuclear tap.

      --
      Will
    42. Re:But Why? by Redmancometh · · Score: 1

      Kyosuke you're assuming they would all hit at the same time...which would be the equivelant mass-energy striking us. The altered trajectories would result in them hitting us at different times.
      So they would burn up with a wimper instead of a bang.

    43. Re:But Why? by Anonymous Coward · · Score: 0

      where I pointed out that merely fragmenting the mass doesn't help you much, said comment completely ignoring the dispersion issue.

      I think you're the one having trouble here. The issue is not a matter of total energy imparted by the asteroid, it's a matter of how much energy is released in either an airburst or an impact. If you break it up enough, you won't have any airbursts or impacts, and other than fucking up some orbital systems all it's going to do is make for a pretty display of lights in the sky.
      Or in other words, the reason fragmenting the mass does help is precisely because of the dispersion issue. So you can't just ignore it like you did.

    44. Re:But Why? by Megane · · Score: 1

      reading from my phone while driving

      What the fuck? Texting while driving is bad enough, but you're posting on Slashdot while driving?

      I think you need a full week's vacation away from anything (other than neurons) that uses electricity.

      --
      #naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
    45. Re:But Why? by Anonymous Coward · · Score: 0

      > detonation depth sufficient to create a substantial mass of solid ejecta propelled by the explosion in (mostly) one direction such that their speed won't exceed some reasonble value (between 10-50 m/s?)

      And how big a percentage of a asteroid do you hope to one could propell out? To guess without doing something actual drilling you'd have no change to even get this and then if it is only a small percentage then only that percentage of the speed is what the asteroid itself moves.

      And while escape speed might not that big, if somebody hopes to fracture the whole asteroid in multiple parts, how much speed could they get from having only a very small part of the asteroid vaporized? (even if one somehow manages to get this done quite deeply?)

    46. Re:But Why? by Will.Woodhull · · Score: 1

      Gee, maybe you should learn to write good. Maybe if you said outright that you were no longer talking about an asteroid impact, but were instead off on some tangent about conservation of momentum, then you would not have failed so badly in your attempt to communicate.

      The thing is, just about everyone who reads slashdot has a thorough understanding of conservation of momentum, so no one was really expecting you to be driveling on about it. We expecting much more from your post. Our expectation of an insightful or informative post led us to try to interpret your remarks in the wider context of the discussion. And not in the grade school context of billiard ball physics that was really all you had to say.

      You're a good person. You have a good vocabulary. You just need to learn to use it. Instead of thinking so much about how to paint a pretty word picture, think more about what you want your audience to understand. And then use whatever words would serve that purpose.

      --
      Will
    47. Re:But Why? by geekoid · · Score: 1

      a) why do you think the will be interested in ending most problems?
      b) AIs would die without us. Someone need to keep the power going.
      c) You assume their logic is incredibly bad. Any device that conclude the best way to reduce cancer patient in a species is to eliminate them is not intelligent.
      d) You also assume we would create them without parameters.

      You're view is right from 1960. Maybe you should update it?

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    48. Re:But Why? by Will.Woodhull · · Score: 1

      A point that is being missed is that the nuclear detonation will occur within moments after a kinetic weapon creates a crater in the asteroid. That crater would still be filled with the gases from the kinetic impact. While that "atmosphere" is transient, it does mean that the nuclear detonation will have a gaseous shock wave.

      The kinetic weapons used by the USA in the Middle East were darts of depleted uranium. Uranium has the interesting characteristic of ablating into a self-sharpening point, which increases the dart's penetration. The uranium gas emitted during ablation would be an excellent vehicle for a nuclear shock wave: its much higher atomic weight would offset its relatively low density.

      --
      Will
    49. Re:But Why? by Anonymous Coward · · Score: 1

      If that's the case we're all fucked anyway, and the money spent on a asteroid-killing mission would be better invested in booze, hookers and drugs.

    50. Re:But Why? by cusco · · Score: 1

      Werewolves, not vampires. I believe that if the bullet needed to be correctly blessed and sanctified with holy water to have a permanent effect on vampires.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    51. Re:But Why? by cusco · · Score: 1

      The nuke vaporizes when it goes off, you're not going to have "radioactive fragments" of it coming down anywhere.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    52. Re:But Why? by ceoyoyo · · Score: 1

      Most of the planet is water, and most of the land is un- or light inhabited. A few air bursts and a lot of pretty meteors is better than one big one landing... almost anywhere. A big asteroid might well do MORE damage if it hits the ocean because the resulting tsunami could take out multiple, widely spaced, coastal areas whereas little explosions over the ocean don't do much damage.

      Besides which, the idea is to divert the impactor in the first place. If you explode a nuke on one side, all of the mass is going to move in the opposite direction regardless of whether it says glued together or not.

    53. Re:But Why? by Anonymous Coward · · Score: 0

      A simple and naïve mathematical modelization would demonstrate that :

      consider :
      case [1], where you have one asteroid with a radius R_1 hitting the earth atmosphere
      case [2], consider the same asteroid splitted in two smaller asteroids, with radius R_2 = sqrt(2) * R_1 (so that the volume is roughly conserved)

      At the entry in the atmosphere, you could modelize that the mass loss per time unit, would be proportional to the apparent surface of the asteroid, which is S = 4pi * R.
      Therefore the relative mass loss per time unit would be proportional to Surface / Volume, which is itself proportional to 1 / Radius.

      Therefore in case [2], your asteroids are being destroyed sqrt(2) times faster (= 40% faster) than in case [1].

    54. Re:But Why? by geekoid · · Score: 1

      Lets see:
      Snotty attitude? check
      Can't think deeply? Check
      Racist? Check.
      Bible quote in Sig? check.

      Why don't you leave Slashdot and go to The Blaze? that way you can raise the average IQs in both places.

      Energy spread across a larger areas and hitting at different times as opposed to all at once, is a good thing.
      500 Tunguska level events is are better then one mass extinction event.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    55. Re:But Why? by geekoid · · Score: 1

      Too bad their aren't any actual data the support the idea that text while driving is more dangerous.

      It's all assumption and really bad testing.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    56. Re:But Why? by Aryden · · Score: 1

      that's what red lights are for.

    57. Re:But Why? by cusco · · Score: 1

      I think the smart thing would be to assemble the transfer vehicle in orbit now. You can assemble an impactor and Mega-Tsar Bomba nuke fairly quickly, but getting that stuff from LEO to somewhere a couple of weeks away from impact is going to require an actual space ship, and that takes a while to build and fuel. Put together the transfer vehicle now, and leave it and its fuel in a parking orbit somewhere not-inconvenient. When/if we discover a threat we can analyze and build whatever is needed to take care of it, ferry it up to orbit, and the most time-consuming part of the process is already there and waiting for us.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    58. Re:But Why? by MiniMike · · Score: 1

      An asteroid this large would be a global problem. Multiple small pieces landing somewhere is better for everyone than one large chunk anywhere. Since the projected timeframe from discovery to impact is about one year, it would probably not be possible to determine exactly where on Earth the asteroid would hit until well after the interceptor was launched. I don't think that "There's an asteroid coming that may destroy your country- mind if we take it out?" will meet with much resistance.

    59. Re:But Why? by Anonymous Coward · · Score: 0

      Silver is for werewolves, not vampires.

      Your dog wants stake...

    60. Re:But Why? by mjwalshe · · Score: 1

      actually you woudl not want the body to break up just add enough delta v to make it miss us.

    61. Re:But Why? by Anonymous Coward · · Score: 0

      Ha ha, I thought you were going in a completely different direction with your ice demo. Take the tray of smashed up ice and throw it at a friend's head, observer the impact. Now that the solid ice and throw it a friend's head (or someone's you're particularly fond of) and see the result. Same amount of ice different impact area/concussion ratio.

    62. Re:But Why? by Corngood · · Score: 1

      How about: take 4kg of ice cubes and drop them on your head from 10 feet. Then do the same with a 4kg block of solid ice.

    63. Re:But Why? by Redmancometh · · Score: 1

      "But if we fired off two or three hundred nukes we can claim those as part of the disarming campaign, test them in live fire conditions, increase the exposure of space travel to people, and watch a bunch of real big light shows.

      that is like 5 wins."

      That guy spoke so much truth that I feel I should repost it instead of vote it up!

    64. Re:But Why? by hinckeljn · · Score: 1

      If there is not enough energy to destroy the Earth, than what counts is not the total amount of energy but the intensity of energy release. Think of one kilogram of gasoline burning slowly and and one kilogram of TNT, EXPLODING! About the same amount of energy, Very different results.

    65. Re:But Why? by RockDoctor · · Score: 1

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

      Very few objects are "small enough to be destroyed" ; most are large enough that the application of energy (i.e., setting off a bomb) will fragment them, producing what is known as shrapnel.

      Take a couple of hundred grammes of explosive and detonate it in free air. It might pop your eardrums if you're in the same room as it, but you're unlikely to even get a bruise from bits of the wrapper hitting you. Now put the same mass of explosive in the middle of a paper bag filled with nails from the hardware store ... and you've built your first nail bomb, beloved of terrorists everywhere.

      The proposal in this article is very specifically about avoiding that fragmentation effect, while applying maximum lateral thrust to the object to move it from a threatening orbit into a less-threatening orbit. But it's going to be a very fine balance between maximising the lateral thrust (particularly important if you don't have much time to act with) and minimising the risk of generating a cloud of shrapnel heading towards Earth. In the mathematical limit, you'd shoot pebbles (bullets) at the rock, so that the rock's orbit was moved. But that would take time to have it's effect.

      There is no quick, simple, easy cheap solution. Hopefully we manage to get distributed around multiple independent locations before we need to try this sort of thing, because at best, it is very risky.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    66. Re: But Why? by RockDoctor · · Score: 1

      Does surface area to volume ratio not come into play?

      Yes, it does : the volume of the atmosphere is finite, as is it's mass and heat capacity. Same for the oceans. If you efficiently distribute a large amount of energy (the kinetic energy of an incoming impactor) through the hemisphere of impact, then you will heat up that half of the atmosphere to the point of (say) burning paper at a colloquial 451degF. Which will not be good.

      Of course, if you inefficiently distribute the energy (say, by having the impactor hit at one small point), then the local temperatures will be much higher, causing an explosion of the vaporised rock at the impact centre. This will throw red-to-white-to-blue-hot material up into the atmosphere (well, actually, no atmosphere would be left, locally ; that doesn't change matters significantly) with 99% of the material on ballistic trajectories that will bring the hot material back down to the Earth's surface over the next few days in a fairly random distribution. So, average temperatures of the atmosphere (for the same impact) would only increase to around 451/2=225.5degF, which would roast flesh, not make it burst into flame.

      Asteroid impacts are bad news. It is probably not coincidence that the earliest traces of life that we can detect on this planet were probably able to tolerate living in scalding-hot water. Previous life-forms that couldn't survive in scalding water, died.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    67. Re:But Why? by MichaelSmith · · Score: 1

      Yeah this part bothers me a bit. Nuclear bombs generate radiation, which heats the air and pops eardrums, etc. The best it can do at an asteroid is vaporise part of its surface, so the impulse from the bomb isn't going to be all that fantastic and most of the energy will be wasted. Makes me wonder of a real nuclear rocket is required.

    68. Re:But Why? by RockDoctor · · Score: 1
      Oh, [SIGH]

      1) Smaller chunks would have a slightly different trajectory so that some would miss us entirely while others

      And the further away you did this, the longer they would have to spread from their origin point. So in the limit, you come back to doing anything you can do, as early as possible. It's probably also best to point the weapon in the correct direction too.

      2) Exploding 1 incredibly large roid in the the lower atmosphere would have the effect you are describing, but by breaking it up, the mass of the particles entering the lower atmosphere would be drastically smaller. Thus, creating less "dust cloud".

      50% (-ish) of our atmosphere is below 8km above sea level. There are dozens of known and measured asteroids and comets bigger than that. The "interesting" impactors would be touching down on the surface before the back side was even into the thick atmosphere, and the leading edge would have taken on the order of a quarter second to travel through the atmosphere.

      OK ; I'll allow for an entry at an angle from the vertical. Give the impactor a half a second to pass through the atmosphere.

      Let's say you have a 10km diameter impactor, and you hit it with the nukes when it is 1000km out (5 times the height of the ISS). Do the geometry : anything that is deflected by less than 40degrees from the original flightpath is going to impact on the Earth. (Actually, I make it 40.8 degrees ; not a significant difference.)

      Now go back to your video of the Space Shuttle 'Columbia' disintegration in the upper atmosphere. What was the cone angle of the debris? 20 degrees? 10 degrees? Not a lot.

      Space defence systems must operate a long way from the Earth. Otherwise, it's far too late. And too little ; but mostly "too late".

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    69. Re:But Why? by RockDoctor · · Score: 1

      The thing is, just about everyone who reads slashdot has a thorough understanding of conservation of momentum,

      Optimist.

      I think that this thread is proving you wrong very adequately.

      Sad. Depressing. But true.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    70. Re:But Why? by RockDoctor · · Score: 1

      I still prefer the odds on the broken up asteroid than the guaranteed end of human life full asteroid.

      I still prefer the odds of having hundreds (or more) of humans in places other than the bottom of a gravity well, so that when the surface has stopped burning and the rest of the debris has settled into a ring (that itself would make space flight planners wish they lived in the clean skies of the 2020s), the re-population of the planet might start.

      Indeed it may be prudent to have a second warhead to explode after the first one to give the pieces more momentum away from the line of impact (we'd need around 100m/s, that's a lot of momentum to be giving to potentially massive lumps of rocky iron).

      In a "shit or burst" scenario, that would be a "nice to have" fallback plan ; whether you'd have enough time between detonation and point of "no point for the second drive bomb" ... would be very situation specific.

      Why do you think that Joe Random Impactor would be "rocky iron" ; they make up only a few percent of observed falls (even if I do have a sample of one on my mantelshelf ; "pretty" does not equal "representative"), while the large, large majority of objects in space are inhomogeneous, brittle, fragile lumps of poorly consolidated lumps of rubble with the cohesive strength of a firm beach sand. Your mental image for planning is inappropriate to the most likely problem.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  6. Spin spin.. by hantms · · Score: 4, Informative

    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?

    1. Re:Spin spin.. by hantms · · Score: 3, Funny

      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.

    2. Re:Spin spin.. by Ginger+Unicorn · · Score: 1

      It's proton torpedoes. Photon torpedoes are from Star Trek.

      --
      (1.21 gigawatts) / (88 miles per hour) = 30 757 874 newtons
    3. Re:Spin spin.. by MacGyver2210 · · Score: 1

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

      --
      If the only way you can accept an assertion is by faith, then you are conceding that it can't be taken on its own merits
    4. Re:Spin spin.. by Anonymous Coward · · Score: 2, Interesting

      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 particularly difficult.

      Alternatively, you could just pile the two impacts on in together from the same direction, just a few seconds (or less) apart so that there is only negligible rotation time between the two hits. Of course that risks your second payload getting hit by debris from the first impact, I don't know how much of a problem that would be. Maybe you could shield the second warhead against this, or shape the first impactor so that debris doesn't fly back up the wrong direction. Dunno. A lot would depend on how much is known of the asteroid's composition and the density of the impact site.

      Finally, you could "hover" at a fixed point relative to the target, smash it with the first payload, wait for a a bit, then after one full rotation your second payload would be nicely lined up above the crater. Unless, of course, the first impact significantly changed the rotational speed / direction of the target...

      Personally I like the idea of a rocket with a nuclear warhead in its belly and a great big one-shot frickin laser (chemical laser?) in the nose. Flies toward the target at high speed, then just before impact zaps a big hole in the surface, flies into the hole and detonates, kablooie!

    5. Re:Spin spin.. by AC-x · · Score: 4, Informative

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

    6. Re:Spin spin.. by Anonymous Coward · · Score: 0

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

      Because asteroids spin, it should be obvious that the center of the crater created by the first half may not be where it's needed when the second half hits.

      There must be some distance between the kinetic device and the nuclear device to avoid destroying the nuclear device with debris from the first impact before it gets close enough to detonate, and that time difference could rotate the crater's center out of position. The true MacGyver would not only know this, but would be able to contrive a solution after the device had been launched.

    7. Re:Spin spin.. by meglon · · Score: 1

      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 really don't think this would be as easy as you think it would be.

      --
      Fascism: An authoritarian and nationalistic right-wing system of government and social organization. See also: NAZI's
    8. Re:Spin spin.. by hantms · · Score: 4, Funny

      It's proton torpedoes. Photon torpedoes are from Star Trek.

      Haha, annoy two sets of fans at once. :)

    9. Re:Spin spin.. by Anonymous Coward · · Score: 1

      Israeli pilots did the exact same thing by hand in 1982 when they destroyed Iraq's nuclear reactor (albeit it was not spinning): some bombs cracked open the reactor dome, then the following pilot had to put his bombs through the hole - while avoiding sporadic antiaircraft fire (IIRC most of the Iraqi soldiers manning the AAA had gone to lunch).

    10. Re:Spin spin.. by poofmeisterp · · Score: 1

      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.

    11. Re:Spin spin.. by hattig · · Score: 2

      I'm sure they could space the two parts exactly one revolution apart (even taking the asteroid's relative velocity into account).

      I think this is the type of problem done in high school mathematics?

    12. Re:Spin spin.. by Dins · · Score: 3, Funny

      "Live long, and prosper" - Gandalf

    13. Re:Spin spin.. by virg_mattes · · Score: 1

      This is a trivial positional problem to solve. Computers have been able to calculate this sort of thing since the Moon landings, so I don't see any insurmountable problems with pulling off doubling a target.

      Virg

    14. Re:Spin spin.. by Binestar · · Score: 1

      "Live long, and prosper" - Gandalf

      With a picture of Obi Wan on a background of Serenity docking at Babylon 5 while being chased by a cylon raider.

      --
      Do you Gentoo!?
    15. Re:Spin spin.. by denzacar · · Score: 1

      "Live long and prosperous, Frodo" - Mr. Yoda

      --
      Mit der Dummheit kämpfen Götter selbst vergebens
    16. Re:Spin spin.. by Anonymous Coward · · Score: 0

      "Live long, and prosper" - Gandalf

      With a picture of Obi Wan on a background of Serenity docking at Babylon 5 while being chased by a cylon raider.

      You fucking moron, "Live Long, and Prosper" is what Gandalf said to Harry Potter right before he blew up the Death Star.

    17. Re:Spin spin.. by Anonymous Coward · · Score: 0

      The moon does not spin relative to the Earth.

    18. Re:Spin spin.. by Anonymous Coward · · Score: 0

      Solving a theoretical problem, and solving that problem in the real world are not the same! Do we have a system to accurately monitor an astroids spin!

    19. Re:Spin spin.. by Anonymous Coward · · Score: 0

      No, its: "Use the force, Harry" - Gandalf (with a picture of Patric Stewart)

    20. Re:Spin spin.. by Will.Woodhull · · Score: 1

      I was envisioning very minimal separation between the kinetic device and the nuclear device, on the order of tenths of a second. The nuclear device would not encounter any solid ejecta, and we have the heat shield technology that would give it ample protection for the very short time needed before detonation.

      --
      Will
    21. Re:Spin spin.. by hackertourist · · Score: 1

      The infographic in TFA suggests that the two components of the satellite will follow each other at a very short distance. Separation is no more than 24h before impact. You need just enough time that the debris from the impact is out of the way, a couple of seconds would be enough.

    22. Re:Spin spin.. by smithmc · · Score: 1

      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.

      That'll work great, as long as there's an exhaust port on the asteroid about the size of a womprat. Then, all we need to do is build an X-Wing...

      --
      Downmodding is the refuge of the weak. Don't downmod, make a better argument!
    23. Re:Spin spin.. by geekoid · · Score: 1

      "Do, or do not. There is no 'try'" - George Bush.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    24. Re:Spin spin.. by kaatochacha · · Score: 1

      Crap, we might actually need rocket scientists for this...

    25. Re:Spin spin.. by geekoid · · Score: 1

      Difficult! well shit, I guess we should give up and die.

      Oh, wait, maybe the second one will be able to change speed and velocity to correct or changes?
      Maybe it will land via command and THEN detonate.
      I know, shocking, right?

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    26. Re:Spin spin.. by cusco · · Score: 1

      Yes, they're called 'telescopes', but they've only been in use for about 400 years so we haven't had much practice with them yet.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    27. Re:Spin spin.. by cusco · · Score: 1

      Yes, it does. One spin every 28 days.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    28. Re:Spin spin.. by Anonymous Coward · · Score: 0

      Was that in Matrix 3 or 4?

    29. Re:Spin spin.. by meglon · · Score: 1

      ...and maybe Bruce Willis will be available.....

      Having a realistic approach to something is usually far better than being hysterical. Hollywood is a far stretch from reality; it probably shouldn't be considered current technology just because it shows up in a movie.

      A better choice in the whole matter would be to invest in the ability to see these smaller objects while we still have time to allow us to deploy technology that actually exists, or evacuate the impact area. Investing into some technology to deflect them in shorter time spans would also be a good thing, however, it's not going to be "profitable," so private corporations are not going to be doing it, and with the current "anti-common good" sentiment pervasive in a certain segment of our society, government won't be investing in it anytime soon... probably until something impacts the US.

      --
      Fascism: An authoritarian and nationalistic right-wing system of government and social organization. See also: NAZI's
    30. Re:Spin spin.. by denzacar · · Score: 1

      "Do, or do not. If it's done it can't be done again." - Mahatma Gandhi

      --
      Mit der Dummheit kämpfen Götter selbst vergebens
    31. Re:Spin spin.. by Anonymous Coward · · Score: 0

      You must have missed the "relative to the Earth" part of his statement. Yes, the moon spins once on its axis every 28 days whilst at the same time taking 28 days to orbit the earth. Excepting libration effects, the moon does not spin relative to the Earth.

    32. Re:Spin spin.. by Ginger+Unicorn · · Score: 1

      it reminds me of this gem

      --
      (1.21 gigawatts) / (88 miles per hour) = 30 757 874 newtons
  7. Don't asteroids rotate? by will_die · · Score: 2, Insightful

    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.

    1. Re:Don't asteroids rotate? by AC-x · · Score: 4, Insightful

      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.

    2. Re:Don't asteroids rotate? by peragrin · · Score: 1

      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.

      --
      i thought once I was found, but it was only a dream.
    3. Re:Don't asteroids rotate? by Anonymous Coward · · Score: 0

      good idea - spin the asteroid at a high rate after the bomb is in the crater, then the explosion does even more scattering.

    4. Re:Don't asteroids rotate? by Anonymous Coward · · Score: 2, Insightful

      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.

    5. Re:Don't asteroids rotate? by Anonymous Coward · · Score: 0

      There's the small issue that this would have to be done at rather long range so that the spacecraft wasn't destroyed / disabled by the first nuke. Also if the threat wasn't entirely certain it could increase the political difficulties involved with the launch.

    6. Re:Don't asteroids rotate? by poofmeisterp · · Score: 1

      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!

    7. Re:Don't asteroids rotate? by MachineShedFred · · Score: 2

      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.

      --
      Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
    8. Re:Don't asteroids rotate? by Anonymous Coward · · Score: 0

      Launch them all from somewhere where you don't care about the nuclear fallout then, like Florida or France.

    9. Re:Don't asteroids rotate? by gmuslera · · Score: 2

      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).

    10. Re:Don't asteroids rotate? by Dins · · Score: 1

      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.

    11. Re:Don't asteroids rotate? by strength_of_10_men · · Score: 1

      I doubt that something like this will be designed by just one person. Mistakes happen, even to rocket scientists. To wit

    12. Re:Don't asteroids rotate? by AC-x · · Score: 1

      You know what you're doing in your comment? It's called assuming.

      You know what the previous poster was doing in their comment? It's called "assuming these researchers, who have probably spent years/decades in space science, don't know that asteroids rotate".

    13. Re:Don't asteroids rotate? by Anonymous Coward · · Score: 0

      I'm imagining the scenes in Battlestar Galactica where they are launching nuke after nuke after nuke at each other.

      And then the asteroid activates its FTL drive just as they are about to impact.

    14. Re:Don't asteroids rotate? by poofmeisterp · · Score: 1

      You know what you're doing in your comment? It's called assuming.

      You know what the previous poster was doing in their comment? It's called "assuming these researchers, who have probably spent years/decades in space science, don't know that asteroids rotate".

      I hear ya, but I never trust people going for grant money. ;)

    15. Re:Don't asteroids rotate? by Minwee · · Score: 1

      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?

      I used to think that someone smart enough to land a space craft on Mars could figure out how to convert to and from metric units, test their own code, and not spend several weeks ignoring critical warnings. So I have been wrong before.

    16. Re:Don't asteroids rotate? by AC-x · · Score: 1

      Over-confident management resulting in lack of thoroughness and repeatedly ignoring warnings is nothing like not knowing basic things about astro-physics.

    17. Re:Don't asteroids rotate? by AC-x · · Score: 1

      Failure of management culture (which was the root cause of Mars Climate Orbiter) is not the same as "no-one else knowing that asteroids rotate".

    18. Re:Don't asteroids rotate? by geekoid · · Score: 1

      Are you really that stupid? just pepper the object we want to move in a specific direct?

      Just.. shut up.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    19. Re:Don't asteroids rotate? by geekoid · · Score: 1

      "a nuclear missile exploding probably doesn't mean a nuclear detonation."
      Never, not probably doesn't.

      Your point is valid. even if it did mean 1 or two would detonate(again, it can't happen) I would be for it.
      In fact, we can pack them in container that will survive an explosion without breaking containment.

      http://www.youtube.com/watch?v=OjrRZ-9jyAM

      I know there is a test where they do a rocket explosion as a test, but I can't find the video.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    20. Re:Don't asteroids rotate? by geekoid · · Score: 1

      No, it's called 'Rocket Science'. They learn about spin, that's a fact.

      Of course, why people here assume it wouldn't be a controllable vehicle with autonomous capabilities is beyond me.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    21. Re:Don't asteroids rotate? by geekoid · · Score: 1

      Lets put this is perspective:

      IT would be more like sending a lander to mars and through a mistake accidental landing it on Pluto.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    22. Re:Don't asteroids rotate? by geekoid · · Score: 1

      " if the impactor manages to change something probably the nuke wouldn't be needed anyway"

      way to miss the point.
      This is to take a look at the feasibility of moving an asteroid where we don't have enough time for a nudge to work. It needs a push.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    23. Re:Don't asteroids rotate? by cusco · · Score: 1

      If we could ensure that most of the congresscritters were assembled downwind to watch the launch then even a launch failure would be success . . .

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    24. Re:Don't asteroids rotate? by cusco · · Score: 1

      Really? The asteroid moves through space as well as spins? Damn, we'd better tell the researchers, I don't think anyone working in the fields of space science ever knew that.

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
    25. Re:Don't asteroids rotate? by Minwee · · Score: 1

      And yet the results are indistinguishable. Funny how that works.

    26. Re:Don't asteroids rotate? by AC-x · · Score: 1

      Except some random /. poster questioning whether people at NASA know software management, development and unit testing well enough probably does have a point while someone questioning whether people at NASA know that asteroids rotate is probably talking out of their own asteroid.

  8. Simulate or it didn't happen! You know what I mean by CuteSteveJobs · · Score: 2, Interesting

    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.

  9. Shotgun by Anonymous Coward · · Score: 0

    So instead on on object hitting the earth, we'll have many fragments that are radioactive, great!

    In reality the first we'll hear about one of these asteroids is when it becomes visible, which will be when it warns up, which will be when it hits our atmosphere, which will be about 1 second before impact!

    1. Re:Shotgun by SteveAstro · · Score: 2

      So instead on on object hitting the earth, we'll have many fragments that are radioactive,!

      Nukes can be designed to have a lot of residue, or not a lot of residue. I'll take mildly radioactive rocks than a wiped out city.

    2. Re:Shotgun by Anonymous Coward · · Score: 0

      Only the bomb debris itself is radioactive, not the rocks that it is sticking to. It is one bomb. Taking global atmospheric testing into account we have already suffered some of the effects of a moderately size nuclear war.

  10. And then it still hits by Anonymous Coward · · Score: 0

    So instead of an asteroid hit, we get a nuclear asteroid hit? I mean, in the case where the asteroid doesn't get deflected and it still hits us. Awesome!

    1. Re:And then it still hits by SteveAstro · · Score: 1

      Yeah right, like you'll be able to tell the effects of 1Mt of bomb in 100Mt of impact damage

  11. Obvious answer by maxwell+demon · · Score: 5, Funny

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

    --
    The Tao of math: The numbers you can count are not the real numbers.
    1. Re:Obvious answer by RobinH · · Score: 1

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

      FTFY

      --
      "I have never let my schooling interfere with my education." - Mark Twain
    2. Re:Obvious answer by Anonymous Coward · · Score: 0

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

      And start mining

    3. Re:Obvious answer by Aryden · · Score: 1

      so that it starts annihilating our thousands of satellites.... RAMMING SPEED!

    4. Re:Obvious answer by gatkinso · · Score: 1

      I fail to see how more bitcoin will help in this case.

      --
      I am very small, utmostly microscopic.
    5. Re:Obvious answer by Anonymous Coward · · Score: 0

      More bitcoin will ALWAYS help.

  12. Messy solution by marcroelofs · · Score: 0

    If we'd be able to make a hole and then point a nuke into that hole we'd also be able to have it 'land' on the surface an explode/push the asteroid to a different track. Maybe 2 or 3 in a row.
    Even if you could destroy an asteroid of significant magnitude with a nuke, it would be just as dangerous and less predictable afterwards.

    I find it hard to believe that this is all a scientist can come up with.

    1. Re:Messy solution by Aryden · · Score: 1

      In your experience, is it easier to push 1 large and heavy object than it is to break that object into smaller pieces and push them individually? I know in my experience, it's easier to pack all of my books into small boxes and carry them than it is to try to move all of my bookshelves at once.

    2. Re:Messy solution by gatkinso · · Score: 1

      The only prediction you need to know post strike is: will it miss? After that, who gives a damn.

      --
      I am very small, utmostly microscopic.
    3. Re:Messy solution by Anonymous Coward · · Score: 0

      Bad analogy. In you experience, is it easier to quickly move a large box of books or to explode it into a whirl of confetti and move each fragment individually?
      The solution is not complete without the astronomical equivalence of a broom and a dustpan.

    4. Re:Messy solution by drinkypoo · · Score: 1

      If we'd be able to make a hole and then point a nuke into that hole we'd also be able to have it 'land' on the surface an explode/push the asteroid to a different track.

      That begs the question, does A in fact mean B? Answer, probably not. Landing requires cancelling out your relative velocity, crashing doesn't. The first part will behave like a bunker buster. The second part goes off right before impact. Conclusion, it's a hell of a lot easier to crash than to land, and therefore physics-you-fail-it.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    5. Re:Messy solution by cusco · · Score: 1

      Do you have a large fan?

      --
      "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
  13. Just send Bruce... by ko7 · · Score: 1

    Us 'old guys' know how to kick some serious ass....

    1. Re:Just send Bruce... by Anonymous Coward · · Score: 0

      Yeah, and you could call it "Springsteen on the rocks"

    2. Re:Just send Bruce... by Anonymous Coward · · Score: 0

      How about the young Bruce?

    3. Re:Just send Bruce... by Dins · · Score: 1

      Pretty sure he meant Bruce Willis...

  14. Señor Bong... by SuperGus · · Score: 1

    ...is going to hit it. With an impactor.

  15. Sad by ThatsNotPudding · · Score: 1

    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.

  16. You know there is no explosive force in space... by EmagGeek · · Score: 0

    All a nuclear device would do in space is heat it up, pretty rapidly, maybe enough to thermal-stress-fracture it into several pieces, but nevertheless a nuclear weapon in space is not going to blow an asteroid (or anything else) to bits.

  17. Re:Simulate or it didn't happen! You know what I m by Aryden · · Score: 3, Insightful

    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.

  18. Re:Simulate or it didn't happen! You know what I m by gatkinso · · Score: 2

    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.

    --
    I am very small, utmostly microscopic.
  19. Re:You know there is no explosive force in space.. by gatkinso · · Score: 1

    It is if it goes off deep inside the thing (hence the crater and penetrating warhead). No air needed for shockwave - the material of the asteroid will do fine.

    http://en.wikipedia.org/wiki/Sedan_(nuclear_test)

    --
    I am very small, utmostly microscopic.
  20. Won't work if the asteroid is rotating by Wormholio · · Score: 1

    If the asteroid has any rotational motion then the crater created by the first impactor will have moved out of the way of the second.

    --
    "Education is not the filling of a pail, but the lighting of a fire." -- William Butler Yeats
    1. Re:Won't work if the asteroid is rotating by gatkinso · · Score: 1

      Not going to matter much if the warhead is only a second or so behind.

      --
      I am very small, utmostly microscopic.
  21. Re:You know there is no explosive force in space.. by Christian+Smith · · Score: 1

    All a nuclear device would do in space is heat it up, pretty rapidly, maybe enough to thermal-stress-fracture it into several pieces, but nevertheless a nuclear weapon in space is not going to blow an asteroid (or anything else) to bits.

    The heat would vapourize the rock, which would at least expand and exert some force on the rest of the asteroid. If the nuke was embedded in the asteroid before exploding, the vapourised rock would expand inside the asteroid, and probably significantly fracture the asteroid, perhaps into several pieces. And those individual pieces, as well as being less mass than the combined mass before (because of the mass lost to vapourised rock) would also be on a different trajectory to before, and so perhaps missing earth entirely. I think that's the point.

    Also, don't think of asteroids as necessarily solid rock like you'd find on earth. They are just as likely to be coalesced space rubble, and not very tightly bound together due to insufficient gravity.

  22. Re:Simulate or it didn't happen! You know what I m by poofmeisterp · · Score: 1

    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!

    :-)

  23. Re:Simulate or it didn't happen! You know what I m by david.given · · Score: 2

    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 entirely on how hard the nuke pushed them and how long they travel before impact.

  24. Re:You know there is no explosive force in space.. by poofmeisterp · · Score: 1

    All a nuclear device would do in space is heat it up, pretty rapidly, maybe enough to thermal-stress-fracture it into several pieces, but nevertheless a nuclear weapon in space is not going to blow an asteroid (or anything else) to bits.

    Well, we have to play with toys and money to test that and be sure.

  25. As long as it is not spinning by Squidlips · · Score: 1

    If the asteroid is spinning (as it surely must be) then this maneuver is much harder...

  26. Re:You know there is no explosive force in space.. by gatkinso · · Score: 1

    Depending on the asteroid size and composition I'd be worried that the warhead would drill through the asteroid entirely and exit out the far side. I guess you could start a watchdog timer to trigger a few ms after impact no matter what.

    --
    I am very small, utmostly microscopic.
  27. Re:Simulate or it didn't happen! You know what I m by Anonymous Coward · · Score: 0

    Yep, even if the asteroid were pulverized, the kinetic energy still would be absorbed by the atmosphere and possibly turn the biosphere into an oven.

  28. Re:Simulate or it didn't happen! You know what I m by MachineShedFred · · Score: 1

    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 rather have 200 smaller asteroids pepper the Pacific and maybe some farmland in China and the western US than one big ass rock land in the ocean and cause a tsunami that wipes out a third of a continent.

    --
    Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
  29. What about fallout by Anonymous Coward · · Score: 0

    Wouldn't our atmosphere be poisoned by nuclear fallout?

    1. Re:What about fallout by Anonymous Coward · · Score: 0

      Wouldn't our atmosphere be poisoned by nuclear fallout?

      We've detonated thousands of nukes over the past century, and hundreds of them were above-ground atmospheric tests. Even if the debris cloud hit earth (which it wouldn't, that's the whole point!), one teensy bomb's worth of fallout into a planet the size of Earth's, is negligible in comparison to what we've already done with no ill effect.

  30. Using a nuke might bot be a great idea either by erroneus · · Score: 1

    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 course, all of that crap has to stay in orbit ready to be launched.

    I am sure all of this is much more complicated than I imagine it to be but I think the generalities are basically sound.

    We have amazing ability to destroy vast portions of our planet. Why are significantly smaller rocks such a challenge? (Oh, that's right, because the targets are actually people, not the planet.)

  31. I'd like to volunteer! by Iridium_Hack · · Score: 1

    To keep the device in my backyard ready for launch. The Smiths live next door and they've been getting ahead lately.

    1. Re:I'd like to volunteer! by Arrogant+Monkey · · Score: 1

      Damn you Jones! How the hell am I supposed to keep up with that!

  32. Re:Simulate or it didn't happen! You know what I m by Afty0r · · Score: 1

    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...

  33. Sounds great.... by TimO_Florida · · Score: 0, Informative

    Sounds great until you realize that all asteroids have all kinds of spin. This not only makes hitting the same hole problematic, but even if you did the hole may not be pointed at a direction you want the ejected thrusting gasses to fly....

    1. Re:Sounds great.... by Lumpy · · Score: 1

      Yup. and hope to hell your hole is at center mass and not off by a little bit or you simply turn all that energy into a rapidly spinning killer asteroid.

      --
      Do not look at laser with remaining good eye.
  34. Re:Simulate or it didn't happen! You know what I m by virg_mattes · · Score: 1

    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?

    Firstly, setting up such a simulation is trivial so I'm sure it would be part of the plan. And to answer your question, vaporizing a big hole in one side would be extremely effective, since unlike an underground detonation there's no atmosphere in space. Turning a sizable divot in one side of an asteroid into liquid or gas would turn the divot into a natural rocket jet, as the matter blew off into space unrestricted by any air pressure. That kinetic energy would push the asteroid in a predictable direction, and that's the whole point of the operation.

    Virg

  35. Re:Simulate or it didn't happen! You know what I m by Anonymous Coward · · Score: 0

    Actually, for most asteroids, the nuke is the best way to impart kinetic energy on it.

    The blast will evaporate the top layer of the asteroid, giving impulse to the rest of it in the other direction.

  36. Re:Best Way To Nuke a Short-Notice Asteroid by Anonymous Coward · · Score: 0

    DON'T!

    Why not?

    Nuke the site in orbit, it's the only way to be sure...

    Captcha: maneuver

  37. Half of the solution by gmuslera · · Score: 2

    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, even if should be easier to spot bigger ones). Maybe with more of these we could improve detection rate before is too late.

  38. Re:Simulate or it didn't happen! You know what I m by Grishnakh · · Score: 1

    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.

  39. Re:Simulate or it didn't happen! You know what I m by Grishnakh · · Score: 1

    For the atmosphere to be heated up by the kinetic energy in an asteroid (or a bunch of fragments of one), it'd have to be a really enormous asteroid. We've had lots of asteroid impacts in our prehistory and they didn't turn the biosphere into an oven.

  40. Re:Simulate or it didn't happen! You know what I m by Anonymous Coward · · Score: 0

    About 10 km in diameter would do it.

  41. Re:Simulate or it didn't happen! You know what I m by MindStalker · · Score: 1

    A little bit of trivia, over 40 tons of space debris hits the earth every day. The earth can handle a lot of small asteroids much better than it can handle one large asteroid.

  42. Soo... by denzacar · · Score: 3, Informative

    That is true, but it really doesn't matter all that much if 1.0e9 tons hit you in the form of a few large fragments or a million small ones.

    Firing birdshot, buckshot and slugs has exactly the same effect on the target?

    You are aware that our planet is continuously peppered by space debris, amounting to something like 10000 to 1000000 tonnes per year?
    Seen any nuclear winters lately as a result of all those impacts? Or those "toxic nitrogen oxides from the atmosphere heating" you're talking about?

    There's an ocean of air above our heads, thousands of kilometers deep, perfectly capable of absorbing all of the impact from the smaller objects - be it kinetic or chemical.
    The big objects are a problem cause they make it through those thousands of kilometers largely intact.

    Just like with birdshot.
    Stand far away, and it won't even scratch the target.
    Fire a slug of the same mass, from the same distance and with the same load, and it will go right through the target.

    --
    Mit der Dummheit kämpfen Götter selbst vergebens
    1. Re:Soo... by Anonymous Coward · · Score: 1

      The ocean of air isn't thousands of kilometres deep. Depending on how you measure it you could say it's not even hundreds of km deep- given the space station is orbiting fine at an altitude of 300+km without significant slow down.

    2. Re:Soo... by Wraithlyn · · Score: 1

      There's an ocean of air above our heads, thousands of kilometers deep

      Thousands of km???

      Try "about a hundred"... and 75% of the atmosphere is within the first 11km. (Source).

      --
      "Mind, as manifested by the capacity to make choices, is to some extent present in every electron." -Freeman Dyson
    3. Re:Soo... by PoolOfThought · · Score: 1

      I don't think denzacar was talking about it linearly. Especially since he was talking about it being spread out. And also because the discussion is about air... no one talks about air using linear measurements.

      The way I understood it was that there was all this volume of atmosphere that the these items would be going up against. That's why the more spread out it is the better. The more you spread it out the more volume of atmosphere there is to absorb the impact.

      As far as the 1000s comment I would say that if you've got a barrier at least 11km deep (containing 75% of the atmosphere as you say) and you can spread out the impact over 100km of surface area then there's your 1000km of atmosphere that is absorbing the impact.... as opposed to it hitting in one much smaller area that puts up far less of a hindering force.

      That's just my understanding of what denzacar said... but my interpretation may not necessarily be correct and I'm not intending to put words in their mouth.

      --
      My present is the activity I am currently engaged in with the purpose of turning the future into a better past.
    4. Re:Soo... by Anonymous Coward · · Score: 0

      There's an ocean of air above our heads, thousands of kilometers deep, perfectly capable of absorbing all of the impact from the smaller objects - be it kinetic or chemical.

      Sorry for being a bit pedantic, but the atmosphere is not thousands of kilometers deep. It's not even hundreds. The usual definition of the border with "outer space" is 100 km. The International Space Station orbits at 370 km up.

    5. Re:Soo... by RockDoctor · · Score: 1

      You are aware that our planet is continuously peppered by space debris, amounting to something like 10000 to 1000000 tonnes per year? [tulane.edu]

      Perfectly well aware of it, thank you.

      1,000,000 tonnes, assuming 1.8 tonnes/m^3 is about 51m radius. Around three times the size of the Chelyabinsk impactor and so around 27 times it's effects.

      A 1km impactor would be around 520,000,000 tonnes. Oh, sorry, that's for ice ; 942,477,796.1 or so tonnes for 1.8SG "rock".

      Slipping a factor of 2 or 3 is banker-level innumeracy. A factor of 500+ suggests that you work in politics?

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  43. Well... by denzacar · · Score: 1

    He did used to take month-long vacations in the stratosphere, and he strolled all alone through a fallout zone, so...

    --
    Mit der Dummheit kämpfen Götter selbst vergebens
  44. Child's Play by Noexit · · Score: 4, Funny

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

    --

    Never argue with a man carrying a water buffalo

    1. Re:Child's Play by strikethree · · Score: 1

      Yeah but the aliens drop by after a bit. The smaller faster ship is a real PITA to kill. It also shoots at you. :(

      --
      "Someone needs to talk to the tree of liberty about its ghoulish drinking problem." by ohnocitizen
  45. Re:Simulate or it didn't happen! You know what I m by david.given · · Score: 1

    I have heard that this is actually worse --- because the smaller fragments are more efficient at transferring heat to the atmosphere, while a single big impact will absorb a lot of energy into the crust and reflect a bunch more into space. So an asteroid-sized dust cloud hitting the Earth at 11km/s stands a good chance of igniting every flammable object in a thousand kilometre radius. But I can't find a reference for that.

  46. Would earth rather face.... by Anonymous Coward · · Score: 0

    Ten thousand duck-sized asteroids, or one asteroid-sized duck?

  47. Bet the team leader has an ex-wife at the DOD by RevWaldo · · Score: 1

    And there's no way she's going to pass on his crazy-ass theory to destroy the asteroid to the president! Besides, he been living in their old geodesic dome cabin in the Ozarks without a cell phone, so we'd have to send a helicopter out to get him. They dragged him into the Situation Room reeking of booze and reefer - "Sure, you'll listen to me now, now that it's too late.."

    .

  48. Re:Best Way To Nuke a Short-Notice Asteroid by geekoid · · Score: 1

    Much better to die.

    If the dinosaurs where a live, they would point at you and laugh. .. then mumble 'idiot', then eat you.

    --
    The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
  49. Re:Best Way To Nuke a Short-Notice Asteroid by MiniMike · · Score: 1

    Maybe he thinks it will be an easier target when it's on the ground?

  50. Re:Best Way To Nuke a Short-Notice Asteroid by cusco · · Score: 1

    Why? Even if you're one of the folks who think the planet would be better without humans, do you also think it would be better without deer, hummingbirds, maple trees, and whale sharks? An extinction-level impact, even if it's considerably smaller than Chuxlub, will do away with all of them as well.

    --
    "Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
  51. Re:Best Way To Nuke a Short-Notice Asteroid by raynet · · Score: 1

    I am assuming that extinction level impact asteroid wont be short notice one, and smaller ones will just spread into a multiple chunks that do more damage to multiple locations.

    --
    - Raynet --> .
  52. And if it is spinning? by ormico · · Score: 1

    probably not going to be easy/possible to hit it with something strong enought to make a crater, then hit the crater witht he nuke, and then hope the blast sends it off in a safe direction.

  53. Lawrence Livermore presentation from PDC 2013 by ChrisCampbell47 · · Score: 3, Informative

    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/

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

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

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

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

    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

    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 :)

  54. Re:Simulate or it didn't happen! You know what I m by Anonymous Coward · · Score: 0

    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.

    Gravity accelerates a massive object at the same rate as smaller objects. You're second point though is valid. The explosion may modify the trajectory of enough of the pieces to avoid the full kinetic energy of the asteroid being unleashed on Earth.

  55. Re:Simulate or it didn't happen! You know what I m by Anonymous Coward · · Score: 0

    You mean the same way those coronal ejections do?

  56. What about comets? by ekc · · Score: 1

    I realize asteroids are much more numerous in the inner solar system, but we're getting better at tracking them so we would ideally have a longer lead time to deal with any threat. Comets, on the other hand, tend to come out of nowhere, so the short notice scenario is much more likely.

    1. Re:What about comets? by Patch86 · · Score: 1

      The principal of "blowing up a large lump of mass before it hits earth" should be more or less the same regardless of whether the object is in a long period orbit or not (which is the only real difference between a comet and an asteroid with any amount of ice in its composition). The only difficulty would be in spotting your target before it's too late.

  57. But it will just split into... by techsimian · · Score: 1

    ...two medium sized asteroids, we need a plan to the 4 small asteroids.

  58. Re:You know there is no explosive force in space.. by geekoid · · Score: 1

    Let me guess you saw 'Nuke' and 'Asteroid' and then couldn't wait to pick your knuckles up from the floor and then pound your keyboard in a vain attempt to make you fell like you have shown others how smart you are, correct?

    Protip: Reading the article and then posting about what is in the article will make you look even smarter.

    --
    The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
  59. Re:You know there is no explosive force in space.. by geekoid · · Score: 1

    You do know that money spent on these projects isn't actually destroyed, right? It's spent, people get paid, corporations make money.

    --
    The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
  60. Re:Simulate or it didn't happen! You know what I m by Anonymous Coward · · Score: 0

    Am I the only one who finds "roids" annoying?
    Saving yourself from typing "aste" isn't much of a save.
    I could see abbreviating it if it was something like "fluglehoffenscnitzelzingroids", but "asteroids" isn't terribly tasking.

  61. No No No~! by Dareth · · Score: 1

    You have to try to extend your warp field around it to change its gravitational mass and fail. Then hope Q puts it back in the proper orbit after you save his life from a plasma creature.

    --

    I only look human.
    My mother is a halfling and my dad is an ogre, so that makes me an Ogreling
  62. Two impacts by Anonymous Coward · · Score: 0

    Sorry, I do not think that a kinetic energy strike would form a proper sized bell-shaped 'nozzle' for the nuclear device. A better solution, expecially for iron asteroids, is to use a tactical nuke for the first strike, followed by sequential strikes by multi-megaton nukes - the larger the asteroid, the more big nukes. Just to be sure...

  63. How about a non-exploding nuke? by scorp1us · · Score: 1

    Nuclear explosions in space are particularly dangerous to space equipment. What if we use a nuke that doesn't explode per se with one that gets really, really hot. Either turning it into a soft blob that conventional weapons can blast apart, Or hot enough to vaporize the material (likely) iron,and create a jet to alter its orbit.

    --
    Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
    1. Re:How about a non-exploding nuke? by samwichse · · Score: 1

      I don't think you're thinking about how big space is.

      A nuke is bad for space equipment? We're talking hitting an asteroid moving say... 60,000 mph (which travels 1.44 million miles a day) months before it hits earth.

      Even detecting the successful ignition of the device with equipment pointed straight at it might be difficult.

      Sam

    2. Re:How about a non-exploding nuke? by scorp1us · · Score: 1

      The van allen belts will collect and coalesce the ions right back onto the planet.
       

      --
      Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
    3. Re:How about a non-exploding nuke? by samwichse · · Score: 1

      The Van Allen belt only extends ~40k miles from the earth's surface. I'm not sure how they're relevant to something occuring 86 million miles away?

  64. Shotgun effect? by dave562 · · Score: 1

    So rather than one big chunk of space debris hitting the Earth, we instead get a bunch of smaller pieces?

    Whatcouldpossiblygowrong?

  65. Re:Simulate or it didn't happen! You know what I m by mjwalshe · · Score: 1

    er you know space is 3d and the? earth is moving decelerating the fragments will probably mean they miss our orbit as well ?

  66. Nukes in space, what could go wrong? by Nyder · · Score: 1

    I love this idea of Nukes in space, after all, no shuttle has every blown up on it's way to space.

    --
    Be seeing you...
  67. Redirect it to hit the US by Anonymous Coward · · Score: 0

    When it hits, nothing of value will be lost

  68. Actually it's my bad... by denzacar · · Score: 1

    I was going to refer to the volume of the atmosphere, then I changed sentence structure to talk about "depth" and thousands of cubic meters came out as thousands of kilometers of "depth".

    Ah well... should have been doing something else anyway, instead of wasting time on Slashdot.

    --
    Mit der Dummheit kämpfen Götter selbst vergebens
  69. New Best Way? by freshmaker13 · · Score: 1

    How does one go about getting their "New Best Way" certification? And how did this trump sending up a Bruce Willis in a rocket ship and having him shove a nuke into the ground with his space-suited hands?

  70. Just One? by VortexCortex · · Score: 1

    I'm not sure what crack they've been smoking, but it will take a fleet of these considering that this will just make a pock-mark on the asteroids that are large enough to be a threat. The force of the explosion will be lost in directions not facing the asteroid. When we see impact craters on big asteroids, they don't look like bore holes... Don't launch one and wait. Launch EVERY nuke, just in case.

  71. Re:You know there is no explosive force in space.. by poofmeisterp · · Score: 1

    You do know that money spent on these projects isn't actually destroyed, right? It's spent, people get paid, corporations make money.

    Understood. My irritation is that people outside of said corporation are lead to believe that a solution is in the near future or being actively worked on when, in fact, there might be nothing of any significant value being achieved. Sure people are taking the money home, but the problem isn't being solved.

    The statement I just made does not apply if they are actually working hard on finding a solution and have knowledgeable people on staff, of course.

  72. What Could Go Wrong by Anonymous Coward · · Score: 0

    This should also be tagged as "whatcouldgowrong"

  73. Silly Silly "scientist".... by Lumpy · · Score: 1

    A nuke to destroy an asteroid. MAybe a tiny one that will not do much. But a large one a nuke will turn a large meteor into a shotgun blast followed by a large meteor..

    You do a series of nuke impactors to hopefully nudge it, and you need to be doing this when it's still out by mars.

    And we dont have the technology to do this, so it's all just mental masturbation.

    --
    Do not look at laser with remaining good eye.
  74. Install A Really Big Parachute by Anonymous Coward · · Score: 0

    ... or maybe a hang glider?

    That much elemental iron is surely valuable. Instead of throwing it away we should be giving thought to guiding it into a position of future usefulness, IE, one of the LaGrange points.

    ~childo

  75. New Best Way... by hinckeljn · · Score: 1

    Putting things into perspective: Solar radiation power hitting the Earth: ~1.4 e17 W. That is equivalent to the kinetic energy of half a million tons of material hitting the Earth with a velocity of 20 km/s (every second).

  76. 2 nukes and an impactor? by Mirddes · · Score: 0

    why not use 2 nukes?

  77. Re:Best Way To Nuke a Short-Notice Asteroid by RockDoctor · · Score: 1
    If it were really a short notice asteroid ... and there were no alternative ... then it is, as we say in the caves, "shit or burst time".

    The really important thing is to

    (1) not be in the short notice asteroid situation in which case we need to continue improving our detection scopes and projection computing resources. And get every historical astronomical photograph digitised thoroughly so that new discoveries can be post-discovered (identified in 50-year-old plates) if they're there. Or confirmed to not be there. (Both types of data improve estimation of orbits.) Programmes for that are already in work, so the biggest issue is funding. (2) have a back-up plan in the event that the deflection-by-nuke plan fails. Which means, having people (hundreds minimum ; thousands better) living off-planet in a locally-sustained way. That's much harder. But it's already on our species' long-term "to-do" list.

    Are you really going to base the survival of our species on a single-shot effort?

    --
    Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  78. Re:Best Way To Nuke a Short-Notice Asteroid by RockDoctor · · Score: 1

    I am assuming that extinction level impact asteroid wont be short notice one

    Why do you assume that?

    Once we've got all the significant rocks in the inner solar system catalogued, so that we know where they're going to be and they are long-notice visitors. Then the remainder of potential short-notice visitors are the ones coming in at random (-ish) orientations from the Oort Cloud. And they're much, much harder to survey for. And they come in fast and hard, with little warning.

    As we improve out cataloguing of the inner solar system, the remaining probability of a short-notice impactor moves increasingly towards the long-period and single-apparition comets. And, of course, the possible (though never seen), extra-solar impactor.

    --
    Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  79. Re:Simulate or it didn't happen! You know what I m by gzuckier · · Score: 1

    "It's this thing called physics and specifically, astrophysics. ... The gravity of nearby planets and the sun would have a far more drastic effect on the smaller pieces"
    Spoken like a business major.

    --
    Star Trek transporters are just 3d printers.
  80. This is a new idea? by RockDoctor · · Score: 1
    I'm bored with constructive (-ish) criticism, and I'll just carp : this is a new idea?

    Just last week I was listening to an audiobook by Robert Heinlein (you know - the only serious contender that Dr Asimov had for the title "the Master" in the world of science fiction ; him) where Andrew "Slipstick" Libby is introduced into the cast list ... by double-checking the results of calculations for precisely this sort of asteroid-moving explosion. They created the initial crater by physically setting a charge on the asteroid surface, then deepened it with one (or more) nukes in the crater. Same story ; same problems. But Heinlein had the excuse of not having a lot of data to work with about the internal strength and coherence of real asteroids. We're slowing our rate of finding surprises now - because we've gone from seeing examples towards having statistically worthwhile samples of data.

    "Revolt in 2100" was how the audiobook was titled ; the short-story was something different though. "Misfit"?

    --
    Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  81. hmmmmm.... by Anonymous Coward · · Score: 0

    A nuke in the crater... sounds kinky.