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This is not nice perspective, but eventually it will happen. An astronaut falls out of spaceship because of damage caused by collision with other object, or because of suit decompression. The fluids from the body would evaporate, and if any bacteria would survive, than only as spores.

Does it mean the perfect mummification of the body? Or there will be some decay, caused by enzymes from damaged cells, for example?

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    $\begingroup$ I would be very surprised if such experiments (with animals, not humans of course) have not been conducted by both US and Russian space programs. So it would be nice if the answer could cite some papers. $\endgroup$ – horsh Jul 17 '13 at 21:02
  • $\begingroup$ @horsh all assumptions aside, the answers thus far have not cited real data as to what has happened experimentally to carcasses exposed to a space environment. $\endgroup$ – Jerard Puckett Apr 4 '14 at 19:15
  • $\begingroup$ I always thought that if the depressurization is fast enough, for instance from a break in a space suit, then the internal pressure of the body would make it explode. Is this conceivable? So, what you have been describing here would only apply if the body is exposed to vacuum starting some time after death. $\endgroup$ – Alberto Jan 28 '17 at 19:20
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It would seem that the ultra-cold vacuum would kill off most of the bacteria, etc in the body, as well as quickly boil off all of the water content. Here's a lovely description of the process from Focus magazine:

In space we can assume that there would be no external organisms such as insects and fungi to break down the body, but we still carry plenty of bacteria with us. Left unchecked, these would rapidly multiply and cause putrefaction of a corpse on board the shuttle or the ISS. Drifting exposed in the vacuum of space itself, however, this process would rapidly slow to a halt.

The low pressure would initially boil off most of the water and what was left would freeze, halting any biological processes. Depending on the trajectory of the corpse, there might be some warming from the side facing the Sun, but all this would do is accelerate the rate of water loss, leaving only a dried husk.

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    $\begingroup$ Charming text. Still, it is not totally clear what would happen. It is also disputed, how e.g. bacteria would handle the situation. For an example, see Streptococcus mitis on the Moon. $\endgroup$ – s-m-e Jul 18 '13 at 14:35
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    $\begingroup$ @ernestopheles it is clear: without water, life won't (can't) do anything. Most life will die promptly, and while some types will persist in suspension, they absolutely must hold on to what little bit of water that hydrates various biomolecules (proteins, nucleic acids) or else they will be destroyed. Given enough time in deep space, all water will ultimately leave them (though if they're stuck to a comet that could buy them eons), and being anywhere near the sun will drastically accelerate that. $\endgroup$ – Nick T Feb 20 '15 at 3:33
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Other then decay caused on earth by bacteria and such, other factors for decay in space; where decay = loss of pristine mummification of the original freeze dried corpse.

  1. A body in orbit around a sun would be impacted by the solar radiation. A quick search only found research on live tissue. Presumably this would cause some denigration of the mummified cells as well. It is unclear if orbital decay or solar wind damage would be the more significant erode/decay vehicle.

  2. A body in orbit around a planet would likely lose all cohesiveness to orbital decay prior to any significant loss due to other means.

  3. A body drifting in open space, would be subject to micro meteor strikes as well as attraction to any other drifting bodies.

There are many factors, while the mummified body would not decay as fast as an earth bound body, it would not be eternally preserved.

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  • $\begingroup$ Great answer: I'd also add that the freeze/thaw cycle (if the body orbited in and out of the sun) would also cause some 'erosion' - or breakdown of tissues and structures. $\endgroup$ – john3103 Oct 17 '13 at 17:28
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Adding to the other answers, the body may decay very fast when colliding with space debris - depending on it's size. Probably more like 'exploding', as it would be brittle after freezing.

This assumes that the body is in an orbit where other debris exists - put that seems probable to me in general.

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  • $\begingroup$ A body won't be necessarilly frozen. On the orbit around Earth the Sun radiation (on the day side) is strong enough to heat a body to significant temperature. $\endgroup$ – mpv Apr 4 '14 at 9:18
  • $\begingroup$ Ok. But thinking about the typical speed difference when space debris collides ("A lot. Really."), it may not matter that much except for the count of resulting particles. And, as others describe, it would also dry out by boiling, and later sublimation of the water, ending up at least somewhat brittle without being frozen. $\endgroup$ – Volker Siegel Apr 4 '14 at 9:27
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I don't think a body in space woudl freeze, because of the vacuum heat might not be exchanged and thus it would remain in the corpse

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    $\begingroup$ This is not true. Any object would still give off heat by radiation. More importantly for a body, the fluids would boil, not by added heat but by the surrounding vacuum. As most liquids (such as water) cannot exist in a vacuum, this would cause all body fluids to either boil or freeze. $\endgroup$ – Rikki-Tikki-Tavi Apr 20 '16 at 12:40

protected by ForgeMonkey Jan 28 '17 at 22:37

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