Q: Are explosions more or less powerful in space?

Physicist: Brace yourself for a mess of guesses:

I’ve heard (anecdotally, and on Mythbusters) that explosions in water are more dangerous that than explosions in the air.  I don’t know if that has more to do with the specific properties of the medium, or merely with the presence of the medium itself, but (with a reasonable guess) it seems that having material around should help transmit the energy.

For an explosion in space, the only thing that carries the energy to you is light (which you would have gotten anyway) and material from the explosive itself.  So the explosion itself should do less damage, while the shrapnel should actually be more dangerous (in air it would get slowed down, and even somewhat cushioned on impact).

Also, in a medium energy tends to travel at specific speeds (the speed of sound generally) which means that most of the energy will hit you all at once (Shock waves can travel faster than the speed of sound, but they burn up a lot of energy doing it)  An explosion in space will cause material to fly out with a broad distribution of velocities, so you’ll experience the explosion over a more drawn-out time.

That’s all guess work.  If anyone knows anything for certain, please post a comment.

Interesting aside: The famous EMP (electro-magnetic pulse) that follows soon after an atmospheric nuclear detonation would be absent in space (deep space anyway).  The bulk of the pulse is actually generated by the explosion moving the ionosphere (it moves… the ionosphere).

Deep seated pet peev: The kick-ass billowing explosions of Vin-Diesel movies will also be missing from explosions in space.  Instead, the explosion would appear as a “star burst” of material all flying outward in straight lines.

A billowing explosion and a star burst explosion.

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8 Responses to Q: Are explosions more or less powerful in space?

  1. Luke says:

    Answering this question should be NASA’s next mission. If NASA gets my tax dollars, I wanna see some massive explosions IN SPACE!

  2. The Physicist Physicist says:

    A bunch of nukes were tested in space by both the United States and the USSR during the Cold War. Then somebody said; “Hey, this is the stupidest thing anyone has ever done, ever”, and some treaties were signed.
    Also: this.

  3. VVM says:

    explosions in water may be more dangerous because of the density. I do not remember the densities, but air is more empty space than atoms (teacher said). But as an example, if you were to try using a water gun with water and then with air only (using the same force, and trying air instead of water) which shooting would push a target more strongly?
    incredibly awesome site 😀
    where do we submit questions? 😛

  4. The Physicist The Physicist says:

    Try it!
    Also, you can send questions to the email address on the top-right of the homepage.

  5. Vebyast says:

    Ran across this while paging back through the archives, and realized that I might have at least a related resource. It only covers the effects of nuclear weaponry in space, since chemical explosives are pretty pathetic for space combat, but it might be useful anyway.


  6. Damian says:

    I don’t know the full answer but I have seen some youtube videos that give me clues. A gun bullet only can travel a few feet in water, but the shock wave of a small bomb can kill so many fish that type of explosive fishing is illegal. When I was a dumb teenager, i took small firecracker, folded tape and a coin over them, and blew them up in water to experiment. I put it in the toilet, and it broke a hole in the thick ceramic and it needed to be replaced. ( sorry mom). I expected an upward splash, but the shocked wave moved down with enough force to break the thick porcelain.

    The type of bomb that is going off from terrorists like just a few days ago in Brussels that left 34 dead and 170 severely injured, use nails and bbs and shrapnel that fly in all directions and bounce.. Broken glass flies. People know the death count, but tragically the injuries are usually 5x as much. And those injuries are often missing kidney , leg, eye.. No full recovery. So while radiation in space has nothing between you and the bomb, its heat and electromagnetic radiation, if you were shielded for an instant, and all the shrapnel missed, you might have missed the entire destructive effect. ( Except your tin can spaceship would probably be in no shape to get to home. ) The energy dissipates with 1/ distance squared. But on Earth, the fluids including air, near the surface advect the energy in the bomb. They can move it around corners, The fuel air type explosion that happens when a fuel filled plane hits a building at high velocity, and the fuel vaporizes and explodes, or otherwise vaporized, is not even possible in space. And after a bomb explodes, a fire from gas lines, electrical shorts, or the design of the bomb might leave a fire to content with. So i’m going to say, despite the friction in air or water, bombs in space are less powerful because there is no fluid ( air, water), nothing to transport the energy, and no chain reactions, ( using oxygen or combustibles) are likely, and only high explosives with projectiles ( or something toward the nuclear variety) have enough radiation energy to destroy at a distance of say 20 meters.

    Anyways I hope you get a chance to try the A/B test, not with a nuke, please. There are electromagnetic effects that I haven’t accounted for, best choose a high orbit. Start collecting with the outer space data first Be safe!!

  7. Ryan says:

    If explosions in space are starburst explosions, then why don’t supernovas look like the image of a starburst explosion.

  8. The Physicist The Physicist says:

    On the collasal scales of a supernova, the interstellar gasses become important, causing the outgoing material that’s moving at different speeds to tend to bunch up into shockfronts (over hundreds or thousands of years). Look up “stellar bow shock” for some beautiful examples of interstellar gas getting in the way.
    You get more of a “star burst” when some material is traveling much faster than other material, but when there’s stuff in the way that doesn’t keep up for long.

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