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Should Nuclear Devices Be Kept On Hand To Protect Against Near Earth Objects?
Lasrick writes: Seth Baum ponders whether nuclear devices should be kept on hand for the purpose of destroying near-Earth objects (NEOs) that pose a threat to the planet. Baum acknowledges that "The risk posed by NEOs is not zero, but it is small relative to the risk posed by nuclear weapons." Even so, Baum writes, since the consequences of an NEO hitting the earth would be catastrophic, keeping 10 or 20 nuclear devices available might be a good idea, and would be "insignificant compared to the thousands now held in military arsenals."
Actually no it is not.
You do not try and blow up the NEO. You try and deflect it. The idea is that you use the "shaped" nuclear charge design developed for the Orion.
The NEO becomes the pusher plate and you nudge it so that it does not hit the earth.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
A meteorite which does not create a big crater will throw a lot less stuff up into the atmosphere, and will have much less global consequences. Getting a shower of smaller pieces would not be fun, but a single big impact penetrating deep into the crust with equal energy is worse.
If you blow up an object, I very much doubt that all of its pieces are still going to hit you. Some of them will go in the opposite direction, some will land in a slowly decaying orbit, and very few of them are likely to continue on their existing trajectory, and the few that do will have their kinetic energy reduced.
That's assuming that the nuke actually blows it up. Nukes are FAR less effective in space because there's no atmosphere for the thermal energy to create a big shockwave, and there's no solid ground beneath it to amplify the intended direction of said shockwave.
IMO if you want to blow up an NEO, you'll probably want some kind of kinetic weapon akin to a giant bullet, maybe a space born railgun or something.
Still though, nudging is probably a better approach.