Nuke on the Moon

In absence of atmosphere, the nuclear explosions will look very different.

The most notable effect will be the absence of fireball, and all subsequent effects relying on convective flows in the environment - no ascending mushroom. An above-Moon blast will look pretty much like an exoatmospheric blast, without the auroras. There will be a short intense pulse of gamma and light and heat, but no lingering thermal radiation as there will be no blackbody radiation of an incandescent fireball. Some induced radiation from the neutron shower will be on the surface. Neutron bombs may be still employed against structures without extensive shielding, as the lower damage and absence of blast wave will be actually advantageous here.

Surface and subsurface, that's a different song. Still strong differences, but actually something more will be visible. A significant amount of matter will be displaced. The trajectory of the ejecta, especially in the case of a subsurface blast, will be different than on Earth - no atmospheric braking, therefore virtually purely parabolic, and will travel much longer distance, due to lower gravity. Footage of dust plumes from the wheels of the moon buggy will provide some hints here.

For the subsurface blasts, the footages of the Sedan test may be useful, modified by the lack of atmosphere and lower gravity.
http://en.wikipedia.org/wiki/Sedan_(nuclear_test)

Surface blast may be a bit difficult to imagine. There will be a bright flash, virtually no fireball, some incandescent material scattered around, some surface area melted into glass. Much less amount of material displacement than for a subsurface blast.

Nuclear isomers, neutron bombs, hazards of small reactors

There are some voices here calling for beyond-state-of-the-art speculative technology. One of the possibilities, pretty controversial at this moment, is induced gamma emission:
http://en.wikipedia.org/wiki/Induced_gamma_emission
http://en.wikipedia.org/wiki/Induced_gamma_emission:_Hafnium_controversy

Area-denial weapons can use short-halftime isotopes.

Neutron bombs can be used against live targets, with only limited structural damage. In space, a directed emission of high-energy neutrons may have pretty devastating effect on a spaceship crew. Shielding against neutron radiation is fairly difficult, and entirely different than against gamma.
http://en.wikipedia.org/wiki/Neutron_bomb
http://en.wikipedia.org/wiki/Neutron_radiation

On a side note, the ceramic composite armor increasingly common on military vehicles causes them to be more vulnerable against gamma radiation, as the materials contain lighter nuclei (oxygen, carbon, silicon, aluminium, boron...) than ferrous alloys in older types of armor, providing poorer shielding.

From the history of nuclear tech, for atmospheric operations there was a concept of a nuclear ramjet, a variant on V1 with a nuclear reactor instead of a combustion chamber. The prototype engine actually ran.
http://en.wikipedia.org/wiki/Project_Pluto

On a side note, small nuclear reactors are useful but if improperly designed and improperly handled, the service crew can end up dead, with one of them pinned to the ceiling with a control rod ejected from the reactor by a steam explosion.
http://en.wikipedia.org/wiki/SL-1

Directing the blast, gamma lasers, more EMP...

Late to the party, a lot of fun was already done here.

In vacuum, there is no medium to conduct the shock wave. A directional nuke therefore could consist of a suitably large mirror that reflects the thermal and the gamma radiation to the target.

The issue here is with the gamma mirror, as most of the blast energy comes out as gamma waves. That may be a tricky tech to pull. We may refer to gamma telescopes, and the low-angle "grazing" mirrors, for hints. Arrays of such mirrors, flowering out of the center with the fission-fusion core, may look pretty.

Another possibility for directing the energy is using an explosion-pumped gamma laser, researched in the Project Excalibur program.
http://en.wikipedia.org/wiki/Project_Excalibur

Yet another possibility, without an actual blast, relies on nuclear-pumped lasers, where the lasing medium is surrounded by a nuclear reactor. That would allow very high energy density achievable, way beyond even chemical lasers. Rumours say Chinese actively research this.
http://en.wikipedia.org/wiki/Nuclear_pumped_laser
Care needs to be taken to realistically portray the laser beam effects, as there's no medium in space that would scatter the beam and make it visible, and also the beam itself may not be at a visible wavelength. (Which may be used for comedic effect. I can vividly imagine an officer lighting a cigar from a beam of "nothing" in the air, in a test facility.)

A nuke blast in deep space, in absence of a medium, will be visually unimpressive. Just a BRIGHT flash of light and then very rapid decay as there won't be much material to form a glowing fireball from.

On the lower Earth orbits, there will be more effects. The links published here earlier show nice footage of American high-altitude tests. The "Nukes in space: the rainbow bombs" video shows a lot of juicy footage.
http://www.atomicarchive.com/Store/Products/Nukesinspacedvd.shtml

There will be beautiful artificial auroras, and depending on the location, altitude, and yield, there may be widespread EMP effects. Russians played with these toys as well; The K Project is a nice example of the ground effects.
http://en.wikipedia.org/wiki/The_K_Project
http://www.futurescience.com/emp/test184.html
Notice especially the description of the effect on phone lines and a power plant; one of the tests blown ALL the fuses on some lines.

Then there's the already mentioned and underestimated effect of pumping charged particles into Van Allen belts, and their effect on the satellites within reach; see the damage done by the Starfish Prime test on the Telstar satellite. Together with the ground effects on power and telecommunication lines, this can have a fairly crippling effect on the Earth defenses; I assume the military dependence on weakly hardened civilian satellites will be even greater than today. The threat model, devolving from fully nuclear conflict of superpowers through regional wars to fourth-generation warfare guerrilla hunting, together with increased costs of military-only hardware in comparison with equal functionality obtained by leasing civilian sources, will lead to deepening (though not to absolute levels) of this dependence. Moon Nazis aren't something the 2018 military doctrine would expect and be prepared for.

The effects on power lines may be pretty attractive. Check out the various videos of power line malfunctions; the arcing is beautiful.

Regarding visual effect, never underestimate the fear-inducing potential of a thin stream of greyish smoke ascending from a life-important circuitboard. For the knowledgeable technicians in the audience, the ass-puckering potential may be higher than of a full-blown Star-Trek grade sparkly explosion.

Feel free to message/mail me with any nuclear-related questions.

space-NAZI moon nuke!

first off some points about story-line.

If the space-NAZIs are more advanced than their adversaries down here on earth (or even other aliens in space), then they will have the most highly advanced weapons imaginable. Otherwise, their technology could be downplayed, although, knowing the NAZIs, it would not be their lowest priority.

So let's assume the NAZIs are the one's firing the bomb, and not the earthlings (or other aliens) for now. We would need to imagine the most efficient space-nukes possible.

To start with, I don't believe the moon-NAZIs would use a space-nuke, because that is the technology they would have left behind with their adversaries on earth, for them to develop a less-capable technology. So, let's also assume that, if the NAZIs use space-nukes, they can defend against them equally well.

now, onto some cosmic pseudo-science...

the NAZIs would not use the "gun method" to trigger fissile compound implosion. The "gun method" is the standard for most existing bombs and missiles to detonate fissile material, and involves, essentially, a drop-down locking mechanism to connect one atom of uranium-238 to an isotope of uranium-235. The "gun method" depends on uranium as its activation-charge. Now, despite there being better technology developed since then, most of the earth's present arsenal of nuclear weapons use the "gun method."

The "implosion method" is based on the "gun method." Therefore, despite its leading to the innovations of a more "land-mine" or "grenade-like" array for the shell's detonation system (a sort of pressure-sensitive detonation method), this method also could easily have been foreseen assuming the NAZIs themselves bestowed on us the "gun method" for a nuclear weapon.

The best defense against the gun method is the very thing at its core: uranium-238, coated in a material such as lead. Uranium-238 emits minor amounts of radioactivity ordinarily, however can absorb much more than it yields as well. Uranium-238 is also found commonly in nature. Uranium-238 is "depleted" uranium, while Uranium-235 (its less common isotope) is "enriched" uranium.

Now, the "implosion method" is essentially identical to the gun-method combined with the scattering of shrapnel alike a standard explosive. Aside from two points, they can both be defended against in the same manner (depleted uranium shielding). 1) "implosion method" nukes (also called "thermo-nukes" or "H-bombs") explode spherically, while the "gun method" weapons explode in more of a column. 2) the "implosion method" nukes also use plutonium-239, which emits less gamma-rays than plutonium 240, although most of the most advanced nuclear rockets still use plutonium-240.

"Implosion-method" fission-fusion-fission nukes and multi-stage thermo-nukes are superior to the "gun method" atomic-bombs of old. However they remain based on the same technology. Whether the fission is compounded by additional fusion(s) or whether it uses plutonium to accomplish this, would make little difference to the space-NAZIs if they were in possession of anti-gravity propulsion technology in the 1940's.

I'd like to point out, also, that the shape of the explosion of a nuclear device in space depends on two things: 1) the shape of the detonator's charge and the direction it is struck by its activating trigger. 2) the chemical-atomic element that is being exploded. Which brings me to my next point, before I address the implications of use of any form of nukes on the surface of the moon.

If the space-NAZIs are using the nuke, it will be much more technologically advanced than if the nuke were based on existing terrestrial technology. Thus, assuming the same desired end is to be accomplished, the desired results can be obtained in some other fashion than the "gun method" or the grenade-like dispersion "implosion method." However, assuming all other things being equal, you could imagine the space-NAZIs using nuclear bombs, rockets or missiles in space or on the moon.

So, what then could we imagine would be the space-NAZI's most efficient form of nuclear weapon? Assuming the single-electron hydrogen atom is used in the standard terrestrial model for initiating nuclear fission, then space-NAZIs would have learned how to maximize this explosive capacity by using ununoctium, element 118, the "heaviest" element on the periodic table. Ununoctium has not yet been discovered on earth (it is a temporary name until it is), and is present as a gas only under conditions of extreme pressure. It is, in point of fact, metallic gas.

Ununoctium experiences natural radioactive decay at a rate of less than one millisecond per atom. However it also (it is predicted) has a very high boiling point, between 320 and 380K. In other words, rendering a single atom of ununoctium inside, say, a lead projectile, would require an explosion of temperatures in excess of 320 - 380K. Ununoctium has seven electron shells with a configuration outward from its neutrino-core of 2,8,18,32,32,18, and 8 electrons per shell. In short if you bond ununoctium with two more electrons, you achieve a super-symmetric element, ie. the particle form of a force for which currently no known particle exists (ie. gravitation). Ununoctium can thus be predicted to be found in the "gas jets" at the poles of black holes in the cores of spiral galaxies such as our own.

Thus, it would actually be simpler for the NAZIs to "reverse-engineer" their nuclear explosions, and not even bother to encase them in a detonation-device. They could, conceivably, possess the capable for laser-guidance targeting systems, and thus be capable of achieving ray-beam technology for the transportation of their destructive energy delivery system.

However, assuming the space-NAZIs are the ones detonating the bomb, and not necessarily some more advanced species of aliens, then they could be using any form of technology in between the simple "gun-array" nuclear fission bomb and the ray-beam of ununoctium iron-gas.

Now, onto the topic of the explosion occurring on the moon. Obviously there would be different effects from an above-ground, surface-level, deep-impact or buried below ground detonated device. Assuming the space-NAZIs have anti-gravity technology to propel their flying saucers, they will undoubtedly understand that the force of gravity is compounded by the density of mass. The moon has less gravity because its mass is less dense. If you had a more dense object the size of the moon, such as a black-hole, it would obviously exert greater amounts of gravity. However, the gravity on and inside the moon is an important factor when considering the physics of an atomic explosion on, in or near it.

1) an above ground explosion. The physics of this are determined according to figuring the effects of the standard nuclear bomb drop, such as the bombs dropped on Hiroshima and Nagasaki. In theory, you could leave one person standing alive beneath such a blast, if you detonated the bomb directly over the head, having dropped it from some height above them. However this would not hold true in lunar micro-gravity, where the concussive force would encounter no air-resistance either.

2) surface level explosion. Again, the physics will change regarding from which direction the projectile is being fired. If it is dropped from directly above, it will obey the falling rate for an object of its weight on the moon, whereas if it is "skipped" across the surface, it would exhibit not only a different dispersion area, but also be effected by the diminished lunar gravity.

3) deep-impact explosion. If the device were impacted into the moon at a high enough velocity it would ordinarily create a crater on the lunar surface anyway, even if it did not have a nuclear warhead attached to it, then the nuke will compound the crater-effect in the following sequence:
A) the impact will occur, marked by a simultaneous "first light" flash from the bomb.
B) the crater will form as the impact and explosion scatter the debris field.
C) the resulting dust cloud will occur which, as I have specified, depends not only on the shape of the charge, or the missile its vessel, but also on the atomic-element being exploded as well. The dust cloud will be bound by the physics of the combination of lunar-gravity on the one-hand, and lack of atmospheric friction on the other, such that the overall plume of dust from the explosion should produce a complete lunar-surface wide "nuclear winter" after one rotation (month) of the moon.

4) buried below ground explosion. Seen from above ground, this would simply look like a ripple on the surface, stirring up a shock-wave of dust that would settle down half the distance the shock itself would travel below the surface. Depending on what we believe is in the core of the moon, it would trigger earthquakes and possibly the dry-well equivalent of a quick-sand pit of a sink-hole.

In ANY of these events, the radiation from atomic energy is no joke. It is based on triggering a chain-reaction of large-particle decay, and it feeds off all the larger particles around it can find just like a virus. Instead of eating them though, it causes them to radioactively-decay, and thus become radioactive themselves. Imagine, at this point, a wave of fire that combusts everything it touches. Now imagine this on a smaller scale, only invisible to the naked eye. Even this amount of radiation can give one "radiation sickness," and direct exposure to an atomic explosion is going to give you cancer.

Also, a little more information on the exact tonnage or megatonnage of the explosion we are talking about would be helpful too. For example, it would probably be possible to destroy a significant enough portion of the moon to ruin the tidal effect here on earth on which life depends using a bomb of the scale of the Tsar Bomba. Also, one would need to consider the long-term effects on earth of a nuclear explosion in our immediate neighborhood of space. Would there be radioactive fallout (moon dust) on earth if a nuke blew up on the moon? Size of the bomb would determine its reach into space counter to the moon's remaining gravity, based on its density. Likewise, if there were an EMP effect from the blast on the moon, what satellites would be effected? Again this depends on the location of the blast on the moon relative to earth, and also on lunar gravity.

Anyway, these are just a few thoughts I wanted to share. I apologise for not being able to be briefer. PEACE.
- Jon

Sound on the Moon

As almost everyone has pointed out, sound in space is just a silly contrivance of media science fiction.

But the surface of the moon is a different story. A nuclear explosion on the moon would put a lot of kinetic energy into the moon's surface. This kinetic energy would travel very quickly. A Moon Nazi standing on the surface would feel and possibly hear this energy in the form of vibrations.

Of course a Moon Nazi who jumped a few centimeters above the surface would hear nothing, as would anyone in a spacecraft above the surface.

Nukes as a weapon on the moon

It seems nukes in space has been well covered so far.
I see using nuclear weapons against a target on the moon bring up some interesting issues. By the nature of the lunar environment any long term base is going to be hardened to protect against solar/cosmic radiation and vacuum. It is very likely that most of the base structure would be underground with any above ground structures heavily reinforced with thick walls and roof. By thick I mean in the nature of +1 meter or more of concrete (Lunarcrete), or similar material. This also means the base would be well protected against nukes.

The question is how to use the nuclear weapons and make it count.
The idea behind bunker busting nuclear weapons is to generate a large a shock wave through the earth to collapse its target. There are 3 methods on how this could be achieved.

1. Physical entry with a number of small man portable nukes, example http://en.wikipedia.org/wiki/Special_Atomic_Demolition_Munition

2. A ground burst of one very high yield thermonuclear bomb. For example the 9 Mt B53 nuclear bomb from the US http://en.wikipedia.org/wiki/B53_nuclear_bomb

3. Earth Penetrating Nuclear Weapon, a low to medium yield nuclear weapon that penetrates a number of meters (6 to 9 m, but some plans are for extremely high speeds with a hardened penetrator of around 40 m) into the ground before detonation. Example the US B61 mod 11 http://en.wikipedia.org/wiki/B61_nuclear_bomb with a yield of 340 Kt

In relation to the movie.

Method 1. I can't see being feasible to the movie. If you are going to storm the base with a squad of men and a couple of nukes, and it is not intended to be a suicide mission. Then you might as well take the base and not blow it up. Space suites, machine guns, hand grenades and nerve gas are a lot less messy than nukes.

Method 2. Could be good. These weapons need to be lay down to be most effective, that is stationary on the surface. My take on how this would go/look like is - A B53 (or similar weapon) is fitted to the top of a modified lunar lander (unmanned, remotely piloted). The bomb lander detaches from the attacking craft, descends to the surface and lands on the roof of the largest building. One side control rockets briefly fire, rolling the lander over in the low gravity, the weapon now on the ground detonates. I am not exactly sure how a weapon this large (9 Mt) is going to behave in the air less low gravity environment. It should produce a very large crater (something in the rage of 600m in diameter/ 60m deep), ejecting a massive amount of material. Most likely in the stylised asteroid impact style, that is in a ring away from the impact with no ejecta travelling directly up. Definitely no mushroom cloud or slowly climbing debris pillar (need a thick atmosphere for that). The ground shock wave would be very strong and would be easily visible from an orbiting space craft expanding in a concentric ring for a large distance from the detonation point.

Method 3. Might be even visually better for the movie than the massive surface burst. A ground penetrating missile is fired from orbiting attacking craft and travels in a parabolic trajectory. Impacting at speed into the target to a depth of a couple of meters and detonates. The effect would be a bit different to the surface burst. At the moment of detonation you would get a heaving up lift of the shock wave in the form of a mound. The mound would continue to lift, disintegrating into a vertical cone shaped blast of material, exposing (breaking through) a brief plasma bright fire ball (from the vaporised material) that would fade/disperse in about 1 second. As the mound lifted the very strong shock wave would race away in the same fashion as the surface detonation. A lot of the ejected material would have enough velocity to achieve short term moon orbit or even escape the moons gravitational pull. This could pose a hazard to space craft or at least produce gravel being thrown at a tin can effect.

I think earth penetrating would be the best visually for a movie effect. But also I was thinking why just one nuke when a number is just as easy. Take 6 interceptors from NASA’s proposed asteroid interceptor http://www.flightglobal.com/articles/2007/08/03/215924/nasa-plans-armageddon-spacecraft-to-blast-asteroid.html each fitted with a 1.2MT war head, modify all 6 with higher power main engines and control rockets. Fit 4 with special tungsten hardened penetrator heads (that are a ogive shape, see http://en.wikipedia.org/wiki/Nuclear_bunker_buster ) to allow penetration up to 40 m at a speed of 1,200 m/s.
All 6 are loaded onto the attacking ship or ships. For simplicity assume the attacking ship is in mid to high lunar orbit that will pass over the base. A long way from the base one non-penetrating interceptor is launched, firing it engine it accelerates away in a downward angel towards the moon surface. When it reaches a altitude of 1 to 2 m it adopts a trajectory parallel to the surface, travelling cruse missile style to the target, firing the control rockets and main engine to avoid terrain and keep the correct altitude (unlike on earth the rocket motor does not need to fire continuously as there is next to no atmospheric drag, also as the interceptor is travelling above the orbital speed at that altitude the control rockets will have to fire regularly to keep the interceptor down at a low level rather than rise away from the moon).
A short time before interceptor 1 reaches the target the 4 ground penetrating interceptors (interceptor numbers 2 to 5) are launched followed seconds later by non-penetrating interceptor 6. Interceptor 1 unexpectedly (for the base) arrives at target just as the base realises it is under attack (the ship and the second missile launch are detected) and defences are made operational, climbs to approximately 35-40 m and detonates in a low level “air burst” (ok so there is no air, low altitude burst just sounds wrong) .
The detonation would be similar to one in space, doing no damage to any hardened structure, effecting only the first couple of inches of the surface (kicking up little dust/debris) and causing an audible rumble in the base. But it would cook and disrupt any un-hardened structures, defending attack craft and ground defences. While interceptor 1 is inbound and then detonates, interceptors 2-5 followed by 6 travel in a parabolic trajectory accelerating up to the velocity of 1,200 m/s crossing the point where interceptor 1 detonated around 30 seconds after detonation (this should give enough clearance). Interceptors 2 – 4 penetrate in a triangle pattern around the base and 5 penetrates the centre, all travel to a depth of approximately 40m and simultaneously detonate. Causing an extreme shock wave and up lift, and blast of material (with all of the affects described in 2 above except it is 1.2 Mt x 4).
Interceptor 6 arrives seconds latter as the derbies are reaching the altitude 50-70 m and detonates at 50m. Producing a massive plasma fire ball (from the ejecta and vaporised material of the preceding detonations) and blast wave that primarily travels downward but then is sandwiched between the remaining rising ejecta and the surface of the moon, displacing the blast wave (and carried material) across the moon surface.
The point of the last detonation (number 6) is that will obliterate any remaining surface structures, make sure that the job is 100% finished and would vaporise any large material ejected by the penetrating detonations in order to protect space craft and near earth space from added space junk. Plus it would make for some astounding visual effects.

Hope this is helpful.

Reality vs. Movies.

These are "Space-nukes". When they go off, they ignite like a super-nova.

Why bother obeying the laws of physics? The space Nazis have gravity control. They refocus the explosion to turn more of the matter into energy.

A real space weapon is sand. A cloud of sand traveling at 10km a second will do incredible amounts of damage to you.

As has been pointed out no sound.

There is no sound in space as it is a vacuum.
However there is sound inside of ships.
Sound you would most likely do the sound this way.

Camera shows nuke going off with no sound of the explosion.(maybe people talking on radios or sirens going of in ships etc.{I believe it would be better starting off with absolute silence before switching to a different shot/scene.})

Then you change the camera to show a shot from inside a ship.(Big one not a fighter in my opinion.)
You can either have someone looking out a window or someone running/walking down a windowless corridor.
When the blast reaches the ship that is not close enough to be destroyed by the blast but still be hit by a shock wave, play the sound of a metal hull being hit by such a shock wave as the vibrations from such an impact would be heard inside but not outside.(Friction)

For what an impact such as this might sound like watch some footage from films where subs are being hit by torpedoes or depth charges.
It's not quite like metal against metal but more a force striking the metal.

As for what it might look like I don't know enough to help.

No sound of course

Of course there would be no sound per se, it seems strange that you would even ask that question. Since the movie is a comedy you could use any sound you like, such as a whoopie cushion noise, or someone blowing his nose.

If you actually want to be realistic, there might be 'sound' of a sort produced this way:

The nuke will vaporize all of the parts of the warhead (delivery system, casing, tamper, unused fissile material etc) that didn't convert to energy. That will create a rapidly expanding near spherical cloud of plasma and vapor. When the edge of that cloud reaches a ship or something there could be an audible 'whump' inside, sort of like the p-wave of an earthquake, followed by a faint noise sort of like wind whistling over the outside of a building but dying away very rapidly and only if the ship/etc is very close.

The effect would be most dramatic if there is total silence from the moment the nuke flashes until the edge of the cloud reaches the viewer.

I swear that sometime around 1976, at an SF film festival, I saw a version of "Silent Running" in which the nukes did exactly that, but every version I have seen since they went bang coincident with the flash just like in a stupid-ass Star Wars sort of effect.

The effect on the moon would be the same as in space, except that the lower edge of the expanding cloud would 'drag' a bit on the lunar surface, raising dust as it expands. But the dust would only swirl briefly as turbulence is an atmospheric effect and the 'atmosphere' in this case would be quite transient. Once the shockwave passes, each dust particle picked up by it will travel in a parabolic arc back to surface. All dust particles will drop back to the surface at the same rate as without an atmosphere there is no buoyancy either.

That is true for all lunar dust regardless of what raises it. No swirling (unless it was lifted by a blast of gas), and it all falls back to the moon at the same rate regardless of particle size or what lifted it in the first place.

Associated with each nuclear explosion is an electromagnetic pulse (EMP) expanding outward at the speed of light. So that pulse would hit a ship at the same time as the light and therefor any effect on the ship from that pulse would in coincident with the flash. If the ship is not designed to withstand an EMP then it might well cause all sorts of electrical failures, burnt out light bulbs etc. If the ship is designed to resist such an effect it might only dim the lights for a moment.

So remember, the light and EMP would arrive at the observer at the same time. Sound would only arrive later when the edge of the explosion itself gets there, and then would be faint and fleeting (if the observer is to survive).

Sound

I don’t think there would be any sound because there is a vacuum in space and thus nothing to carry the sound waves, which are “density variations in the carrier medium”.