What would happen to a big sphere of water 1 km in diameter if it appeared in stable orbit between earth and the moon?

What would happen to a big sphere of water 1 km in diameter if it appeared in stable orbit between earth and the moon?
Would the sun cook it all to steam, would it freeze to a big snowball, stay liquid or what?

It would evaporate

There isn't a stable orbit between the earth and the moon. The one Lagrange point, which you're probably thinking of, takes constant adjustment to stay in.

>There isn't a stable orbit between the earth and the moon. The one Lagrange point, which you're probably thinking of, takes constant adjustment to stay in.
What about a figure of eight orbit?

I don't think water can exist in space without atmosphere. It would evaporate into a dissipated gas cloud.

Water boils and evaporate if there is no atmospheric pressure, but if the sphere is big enough maybe at some point it has a gravitational force strong enaugh to mantain the water liquid

>There isn't a stable orbit between the earth and the moon.
There's literally thousands of satellites in stable orbits between the earth and the moon right now. Now, would a 1km sphere of water be able to be there without touching the atmosphere and close enough that tidal forces don't break it apart? Who knows.

...

I don't really understand why tho.
Shouldn't the forces between the particles make them stick together? After all there is no real force that pushes them apart, is there?

I think I know why you guys are confused. OP meant an orbit that was lower then the moon's orbit, while Lagrange-point-user thought he wanted the bubble to constantly be in line with the moon and the earth.

Not really. The only forces acting to keep it together is the gravitational force and the surface tension, none of them strong enough to hold it for very long. Being liquid, convection would keep temperature kind of constant, but atoms of the edges would evaporate quickly, in fact it would be sublimating. So the only question is, would all of it evaporate before freezing? I think so, irradiation is quite slow.

Think of it on the particle scale. In a liquid, you have particles moving around in a bunch of different directions, and as the particles leave the surface of the liquid, there are no particles from the outside to push them back in. The result is that each particle rushes off in its own direction, carried by the momentum it had when it left the bulk fluid, which ultimately means that the liquid just vaporizes when it's exposed to the vacuum of space.

so are particles leaving the surface from the inside or is it surface particles leaving? like some sort of escape velocity?

>like some sort of escape velocity?
That's actually quite accurate. Calculate the average velocity of a water molecule based on thermodynamic equations and it will be much less that the escape velocity because 1km in diameter is just so small.

>much less
I mean much more.

LOL. come on Veeky Forums
at thermal equilibrium, the energy distribution of the water molecules can be described by the boltzmann distribution. there will be some collection of molecules with energy sufficient to evaporate, even if the bulk temperature is below the temp necessary for a phase change

except the boltzmann distribution just makes a relation with the average kinetic energy and total temperature of the system. that doesn't necessarily answer how some particles evaporate in a vacuum. unless you're gonna make a relation like Choked Flow across the entire surface.

>bulk temperature T
>X molecules have energy sufficient for evaporation
>that doesn't necessarily answer how some particles evaporate in a vacuum
that fact that you for some reason introduce choked flow as a parameter for consideration only serves to cement your ignorance

the fact you think you can just say it's sufficient without any values cements your autism.

leave a small puddle of water on your kitchen sink. it will evaporate with time.
remember that evaporation boiling occurs when the vapor pressure of your liquid is equivalent to the atmospheric pressure. in space that water will readily evaporate

I don't understand how is that in contradiction to anything that was said before.

>Water boils and evaporate if there is no atmospheric pressure, but if the sphere is big enough maybe at some point it has a gravitational force strong enaugh to mantain the water liquid

then i believe it would turn into an asteroid

>asteroid
comet

comets are made of ice though, they last millennia

When the astronauts take a leak while on a mission and expel the result into space, it boils violently. The vapor then passes immediately into the solid state (a process known as desublimation), and you end up with a cloud of very fine crystals of frozen urine.

Ok, so I did some calculations and the escape velocity would be something like 0.3 m/s. That's very fucking slow.

I'd like to learn more about this. Could an user point me in the direction of some relevant literature/wikis?

That reasoning takes from several areas of physics, but it's very basic. I'd suggest taking classes from Kahn Academy in the areas you are interested in. Then if you want to go further you'll definitely need calculus before taking a book in thermodynamics, gravitation or fluid dynamics.

It depends what state it was in when it appeared. If it appeared as a liquid, it would evaporate pretty quickly because there isn't enough atmospheric (or other) pressure to keep it in a liquid state. If it appeared as solid ice, it would sublimate, but kinda slowly, like a comet.