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."

Comments

You mean NEOs like Russia?

[tlambert]

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

Probably "yes".

Re:You mean NEOs like Russia?

[bill_mcgonigle]

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

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

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

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

Re:You mean NEOs like Russia?

[tnk1]

Reagan was badly upset when he realized that the Russians actually thought that Able Archer 82 was actually a lead up to war. He got a lot more serious about arms control talks after that.

And it is not policy that use of Nuclear Weapons is survivable, the policy as of the latest Nuclear Posture Review is that the US will not guarantee no-first-use, which is not the same thing. However, we do provide that assurance for countries who have signed the NPT.

The idea is that giving a no-first-use guarantee allows the assumption that the US will accept being hit with devastating non-nuclear weaponry and not retaliate because we might not be able to retaliate in "kind" because we don't have a non-nuclear weapon that does the same amount of damage. It also is meant to allow us to maintain a credible threat against heavily militarized countries like North Korea or China without having to match them conventionally. Not providing a guarantee is not the same thing as a definite retaliation, even if something like that came to pass.

Moreover, even your fundamentalist Air Force generals are not going to launch without a reason. They may believe that they will get taken up in the Rapture, but that doesn't mean that they will start the war that kills billions of people to do it. They may be believers in an eventual apocalypse, but only truly crazy people believe that they are the ones who are meant to start it.

Don't get the idea that I feel safe with nuclear weapons around, but I don't think it is impossible for us to avoid destroying the planet with them. In any event, they are here to stay and we need to learn to live with them. I think that enough people have done the calculus in their heads about what they would do if called upon to end the world. Some military folks may perhaps be capable of a first attack out of nowhere, but even the military are not automata.

Effect of nukes on NEOs

[maroberts]

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

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

Re:Effect of nukes on NEOs

[Spazmania]

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

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

Re:Effect of nukes on NEOs

[Tuidjy]

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

Re:Effect of nukes on NEOs

[Moses48]

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

Re:Effect of nukes on NEOs

[g0tai]

Many more pieces, with a lot more surface area to:

1) burn up with.
2) decelerate with.

One big problem becomes less significant the smaller it gets.

Re:Effect of nukes on NEOs

[LWATCDR]

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.

Re:Effect of nukes on NEOs

[ckatko]

While on a practical sense you may be right, the idea that they'll have the same velocity is completely false.

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

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

Re:Effect of nukes on NEOs

[Moses48]

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

Re:Effect of nukes on NEOs

[Urkki]

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.

Re: Effect of nukes on NEOs

[ArmoredDragon]

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.

Re:Effect of nukes on NEOs

[ShanghaiBill]

And where do they burn up? In the atmosphere.

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

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

Re: Effect of nukes on NEOs

[Anonymous Coward]

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

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

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

Shitty risk analysis

[bluefoxlucid]

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

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

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

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

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