While I have seen the idea for nuking Mars’s polar ice caps to release water, the fallout from the thermonuclear blasts could plunge the planet into a nuclear winter which could stop us from colonizing mars faster. However, when I pose the question above, I am not asking about fission bombs. Theoretically, the technology for a fusion bomb is coming, with the promising idea that we can extract energy from colliding atoms instead of pulling them apart, and not releasing deadly particulates into the atmosphere whether it be from nuclear plants or fallouts. So, since I haven’t seen anything really about this alternative; when fusion bomb technology is proven, couldn’t we just use that to colonize mars instead or do we just redirect asteroids to hit mars and hope that does the trick?

  • 11
    $\begingroup$ Fusion bombs have been around for decades, they are called thermonuclear weapons. Electricity from fusion is under development, and while there's been some important progress lately we are still a long way away. Thermonuclear weapons are not 'clean', any nuclear weapon, fusion or not, will create fallout if they are detonated close enough to the surface. $\endgroup$
    – GdD
    Feb 21 at 10:20
  • 4
    $\begingroup$ Voting to close for clarity. This question doesn't make any sense; you don't need to use nuclear weapons to melt ice. I melt ice without nuclear weapons all the time, and it's not by using asteroids either. $\endgroup$
    – Erin Anne
    Feb 21 at 10:34
  • 2
    $\begingroup$ The idea of using nuclear detonations to terraform Mars has been thoroughly "debunked" in the sense that it just doesn't make any sense. The sheer number of nuclear weapons required to affect any planet-wide change is mind-boggling, and it would be faaaaar cheaper to redirect asteroids if you want some high-energy impacts. It is basically just a meme. $\endgroup$
    – Dragongeek
    Feb 21 at 11:10
  • 2
    $\begingroup$ The question 'could nuclear weapons be used to terraform Mars' is a valid one, which is answerable. $\endgroup$
    – GdD
    Feb 21 at 11:19
  • 1
    $\begingroup$ If your aim was really to heat mars (but why though, it doesn't have an atmosphere and it's got carcinogenic dust storms etc.. What you would more likely do it build geostationary mirrors in orbit over the poles. This would efficiently heat the poles at all times, as opposed to intermittent meltthenfreeze cycles. Thermonuclear detonations as they relate to space are basically only to be considered if they are propulsion, and even then,.... $\endgroup$ Feb 21 at 20:02

2 Answers 2


Fusion bombs have existed for decades, they are called thermonuclear weapons, and are many thousands have been produced. A thermonuclear bomb uses a small fission bomb primary to cause the extreme pressure needed to create the fusion explosion. As both contain a fission bomb both plain fission and thermonuclear weapons produce fallout due to the explosion's interaction with the ground, the closer the detonation to the ground the more fallout is produced. A 'pure' fusion bomb would create no fallout, however these do not exist, nor are they likely to in the foreseeable future. Fusion power seems to be getting closer and there have been some breakthroughs lately, however that's not bomb technology (thank the deities of you choice for that one). We are stuck with good old thermonuclear weapons for now, which create fallout.

While the majority of the radioactive products from nuclear explosions decay within the first 3-5 weeks there are some that can last for centuries, Cesium-137 for example has a half life of 30 years. Given it would take thousands of nukes to make a dent in Mars' polar caps the result would mean significant surface contamination lasting centuries. This would cause significant hazard to anyone on the surface, and would contaminate any building materials being used to create habitats, structures, or for soil. This is one of the reasons nukes are not a viable way to terraform Mars.

There are plenty of other reasons, the biggest one is that nukes are great if you want to blow something up, but a really inefficient way of heating anything. You wouldn't use a stick of dynamite to boil a kettle.


when fusion bomb technology is proven, couldn’t we just use that to colonize mars instead

No. Fusion bomb technology is already proven, but it is entirely inadequate for terraforming.

or do we just redirect asteroids to hit mars and hope that does the trick?

We "just" redirect asteroids. We don't need to hope it does the trick; we can model, and hope we didn't overlook something important in our models.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.