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Shards of a shattered planet

  1. Dec 13, 2014 #1


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    There's a short story rattling around in my head. The premise involves an Earth-like planet that has been shattered (not reduced to rubble, but cracked into large pieces).

    It is an artificial catastrophe, to be sure, but exactly what form of weapon or other destructive force was used is open to imagination (you are welcome to posit causes that will lead to the effect I'm looking for, but it is not important).

    What I'm interested in is what form the shards would take. (this would likely be dependent on the nature of the destructive force). I'm looking for the least destruction required to separate a planet into two or more pieces that do not immediately recombine.

    What might I expect the planetary environs to be, say, a century or so after the rending asunder. Obviously, after rounding the sun a hundred times, some of it will be quite spread out into, not a full ring, but an arc.

    My primary question is about how the largest pieces might fare. The Earth is mostly high-viscosity liquid, so the largest pieces couldn't be more than - what? - a hundred miles thick? If that's true, is it safe to assume that no single piece could possibly measure more than a couple of hundred miles across? Any broader and they would simply collapse in on themselves by their own gravity like an eggshell in a closed fist.

    Last edited: Dec 13, 2014
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  3. Dec 13, 2014 #2


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    It's still speculated, the last I heard, that the asteroids are remnants of such an occurrence. Maybe you can start there and work around it a bit.
  4. Dec 13, 2014 #3


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    Well, all our asteroids are ancient and have been reduced by collisions and self-collapse to near spheroids. So not what I'm after.
  5. Dec 13, 2014 #4


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    Take a sp. gr. of ~ 3 for crustal material (the rest ain't gonna be too terribly interesting), a crushing strength of 5-10 kpsi (70 MPa?), Fgfrag ~ 3000d3Gmtest/r2 = 1.6 x 10-6N x r, where r = d/2 is a "mean" radius for the fragment --- solve for a mean diameter or radius that exceeds crush strength for whatever geographic relief is necessary for the story.
  6. Jan 1, 2015 #5
    I think the best approach would be to allow an antimatter rope (or other suitable explosive) to descend onto the equator - so that a toroidal explosion squeezes the Earth into two pieces. If the detonation was little more than minimal and occurred during an equinox, there would be two large pieces in solar orbits that would keep them apart for years.

    Aside from the north and south hemispheres that would each form a molten planet, there would be "splash" from the equatorial section that was most directly squeezed.

    The moon would head off in its own direction.
  7. Jan 16, 2015 #6
    Large pieces would collapse under their own weight into a sphere. Only small asteroid sized pieces could have weird shapes.
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