Nigel,

I was going to delete this entire reply because really, I am far from an expert at any of the relevant disciplines at play here.
I simply approached it as a fun hypothetical and did not mean to speak from any position of authority on the subject.

Having said that, I will leave my original reply as is.

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Touche…. I will concede your point that (mostly) they will stay put.
( Insofar as the immediate area, anyway ).
However, almost all of these compounds will expand.

Even through cellular membranes, I cant think of any bodily fluids that would not flash to vapor at that pressure and temperature.
Direct sunlight or not, the body itself is an enormous source of thermal energy.

I don’t think our intrepid team from CSI: Pluto would have any trouble describing a solid body amid a cloud of gas and vapor as dessicated.

OK.

Just one more question – how? By which I mean how could a body left in the vacuum of space (without direct sunlight) desiccate rapidly?

Bear in mind I’m not saying that bodily fluids will stay fluid, I simply think they’ll stay put. Mostly.

My tongue was pretty firmly in my cheek there.

I haven’t done the math for the boiling point of various compounds at reely low pressures or worked out fast the pressure differential would equalize but combined with the latent heat of the body, I think it would dessicate pretty quickly.

Admittedly there would be pockets of gas trapped within that would take a while to reach thermal equilibrium, but in simplest terms once the only states of matter remaining are solid, its frozen.

I have to wonder how many of the liquids in a human body would remain liquid at near vacuum?
Because once they’re gone, by definition it’s frozen, regardless of temperature.

Define what you mean by “liquid”.

Most of the water in a human body (for example) is not in what you might call liquids (blood, lymph, cerebro-spinal fluid, interstitial fluid and so on). Most of it is in the cytoplasm of cells, where it exists as a kind of gel because of everything else that is present in the cytoplasm of cells.

For the most part, even the liquid components of a human body would not be exposed to vacuum – even in the most vulnerable places (such as deep in the lungs) there would at least be the walls of capillaries between the body’s blood and the external environment.

Our bodies are pretty tough, and we have evolved to deal with having a high-pressure circulatory system. Expose a person to vacuum (where the difference between internal and external pressure is perhaps 7 times what it might normally be) and they will certainly suffer, but you won’t have blood vessels bursting left, right and centre.

So, the saliva will boil from the mouth, and the mucus coating of the airways will rapidly dry out (the stomach may even be emptied too) but most of the body’s fluids will stay inside it and won’t be exposed to the vacuum.

And your definition of freezing is indistinguishable from desiccation, so it does not sit well with me. A body left in a cold part of space probably will freeze, and this freezing will involve water forming ice crystals throughout the body. Due to the damage those ice crystals will cause, some of that ice might then become exposed to vacuum and sublime off, but I think you should not expect a body exposed to the vacuum of space to be desiccated unless it has suffered massive and extensive trauma. Or been there for many years.

So if the corpse is located out beyond Pluto’s orbit, say – wouldn’t it freeze pretty much straight away?

Er, pretty much no.

As the commenter to whom you were responding pointed out, the only way an object in space loses heat is through radiation. Add to that the residual internal heat of the object having first to reach the object’s durface by conduction before it can be radiated, and you have a process that takes time. How much time depends on the surface area / volume ratio.

I have to wonder how many of the liquids in a human body would remain liquid at near vacuum?
Because once they’re gone, by definition it’s frozen, regardless of temperature.

BTW. Aren’t they still going through the WISE data and isn’t it possible they might yet notice more comets still? (Or nearby brown dwarfs and other things hitherto unknown?) Or have they finished that process now?

If it’s near a star such as our Sun (eg. closer than Mercury’s orbit) there’s going to be a lot of radiation to cremate and vaporise the cadaver in question.

But that is an atypical and unlikely spot to be because space is called that because “there’s a lot of it” (movie quote ) and most of space is a *very* long way from any star or highly radiative (?) object.

So if the corpse is located out beyond Pluto’s orbit, say – wouldn’t it freeze pretty much straight away?

As I understand it the cosmic microwave background which you could perhaps call the “temperature” of space far from stars – the vast majority of it – think all the planet’s beyond Jupiter and the vastness of the middle and outer solar system realms – is 3 degrees Kelvin or minus 270-ish degrees Celcius. (Minus 454 Fahrenheit.)

But yeah, space is a vacuum and as such is a medium rather than a place with temperature not really applying exactly if I understand right. Might as well ask what the temp of “water” or “air” is. It depends where and what you’re referring to.