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View Full Version : Using nukes for terraforming?

PlutonianEmpire
2012-Oct-21, 04:48 AM
I saw the other thread on nukes, and was reminded of a B-level sci-fi movie I saw years ago where in the beginning, they detonated nukes over the Martian ice caps to initiate the terraforming process.

Could nuke bombs be used in such a way in real life on cold and icy bodies, in terms of technical feasibility or effectiveness? Maybe not necessarily Mars, but perhaps on larger and more capable/terraformable worlds in other systems?

Shaula
2012-Oct-21, 07:10 AM
Well, latent heat of fusion for water is 334 kJ/kg, specific heat capacity of ice is 2.11 J/C . g

So for each kilo you would need 334+ 2110 x degrees below zero of the surface. Taking Mars at -143 you get 302 MJ per kilo. One ton of TNT puts out 4184 MJ. Therefore per kilotonne yield, assuming it was all absorbed by the ice you would generate 15 tons of water.

The Caspian sea has a volume of 69,400 km3. This is about 7e14 tonnes of water. Or 4.6 million megatonnes of bombs.

So I'd say: Not feasible. Certainly not if you wanted to live there later. Warning: maths being done with only half a cup of coffee inside me. I may need to come back later and check it!

Ara Pacis
2012-Oct-21, 09:57 AM
Nukes have been suggested, but I think they want to use them in a less direct manner, such as breaking up ice masses and spreading dust over them in order to decrease their albedo so that the sun or reflected sunlight can start melting it.

eburacum45
2012-Oct-21, 12:13 PM
Zubrin's plan to terraform Mars uses nuclear propulsion to nudge ice-bearing small asteroids into orbits which eventually collide with Mars. The amount of energy that an asteroid produces when it hits a planet is much greater than the smaller amount of energy it takes to divert them; this uses the gravity of the planet as a multiplier, and would be much more efficient.

By itself nuclear fusion power would too feeble to terraform a world on any reasonable timescale. That isnot counting the fusion in the Sun, of course; you could redirect the light produced by the Sun's fusion to terraform even distant planets, if you had a big enough lens (or a system of lasers).

Noclevername
2012-Oct-21, 12:56 PM
That isnot counting the fusion in the Sun, of course; you could redirect the light produced by the Sun's fusion to terraform even distant planets, if you had a big enough lens (or a system of lasers).

I've heard it proposed that a simple series of light reflectors, if large enough, could be used to focus sunlight directly onto the Martian poles. They could be made of thin aluminum foil.

PlutonianEmpire
2012-Oct-23, 06:14 AM
Well, latent heat of fusion for water is 334 kJ/kg, specific heat capacity of ice is 2.11 J/C . g

So for each kilo you would need 334+ 2110 x degrees below zero of the surface. Taking Mars at -143 you get 302 MJ per kilo. One ton of TNT puts out 4184 MJ. Therefore per kilotonne yield, assuming it was all absorbed by the ice you would generate 15 tons of water.

The Caspian sea has a volume of 69,400 km3. This is about 7e14 tonnes of water. Or 4.6 million megatonnes of bombs.

So I'd say: Not feasible. Certainly not if you wanted to live there later. Warning: maths being done with only half a cup of coffee inside me. I may need to come back later and check it!
Ah, makes sense then, thanks. :)