water in space

[animartco]

I have a question, probably a very silly one but I would genuinely like to know the answer. If someone released a gallon of water from a satellite in close Earth orbit, would it
A turn to gas immediately and dissipate
B remain a blob for a while at least, or
C freeze instantly?

Cheers everone. Animartco.

[Lancashire Lad]

I may be completely wrong here, but I think it might depend on whether the water was released on the "sunny" side of the orbit, or on the dark, "night time" side.

If I remember correctly, the temperature (generally) in space is almost absolute zero, but temperatures in earth orbit can get quite high.

I'm sure that nytecam will be able to put this much more succinctly.

Regards,
Mike.

[animartco]

Thank you Lancashire Lad.
er, there isn't a close earth orbit that could STAY on the sunny side? Perhaps an orbit at right angles to the direction of sun, although I suppose if it wasn't adjusted it would have some night for half the year.

[Lancashire Lad]

Originally Posted by animartco

....er, there isn't a close earth orbit that could STAY on the sunny side?....

My thinking was that it would repeatedly pass through periods of daytime & nighttime. Sometimes being between the Sun and Earth, and sometimes with the Earth being between the Sun and the water.

At the times when the water is behind the Earth, in relation to the Sun, I would think it would definitely become ice. At the times when it is between the Sun and the Earth, I would envisage that it would remain as water, although I seem to recall that Earth orbit temperature can exceed 100 degrees celsius, so it might well become steam, and if that happened, I'm thinking it wouldn't be able to reconstitute into one "blob".

Regards,
Mike.

[thunder]

Originally Posted by Lancashire Lad

If I remember correctly, the temperature (generally) in space is almost absolute zero, but temperatures in earth orbit can get quite high.

Regards,
Mike.

Space is empty (more or less)- there is nothing to have any temperature!

henrya

[thunder]

But to answer the original question - it would depend on how it was released - but it would turn to gas and dissipate in pretty short order.

henrya

[Doggle Avaddit]

Water is what you get when H2O is under enough pressure for it to be a liquid. When released into the near vacuum of Space, it would boil instantly, and form a cloud of tiny ice crystals.

[Jim Ford]

My guess is that it would boil rapidly, depending on its initial temperature, and in doing so would lose latent heat of evaporation until the remainder froze. It would then sublime - turning from its solid phase directly into its vapour phase, without going through its liquid phase.

Jim

[Lancashire Lad]

Originally Posted by thunder

Space is empty (more or less)- there is nothing to have any temperature!

henrya

Strictly speaking, space itself has an overall temperature close to, but not quite, absolute zero, I was thinking more of the temperature that would arise from radiated heat (from the sun) into an object floating in Earth Orbit. (In this case the water).

However, my suggestion was quite wrong, and I agree with these posts, as I had completely forgotten my basic physics, , and should have taken into consideration the fact that water would boil at ever lower temperatures as the pressure was reduced from that on earth, (or in a space capsule), to the "no pressure" scenario of space itself.

So, as said, if it was suddenly released into space, it would boil virtually instantaneously, after which any residual water molecules would instantly freeze (desublimation) into tiny ice crystals.

Regards,
Mike.

[animartco]

Thank you all so much for your responses. One point someone raised. Would the steam or ice crystal disperse or would they float around as a blob of molecules? What I'm asking I suppose is would they have enough attraction to stay together? Probably not.
One thing I have never understood about comets, is, if they are throwing off substance in sublimation, to the extent they appear to be by the size of their tails why haven't they all disappeared long since? Are they picking up extra ice, and if so how and where?