It expands because it is not under the pressure it was. It is first agitating to get to be expanded. This agitation is due to dense agitation creating heat due to it.
So it not freezing? i.e. the exact opposite of what you are claiming?
Now tell me about your reality that goes against what I'm saying.
Your reality. What you physically know, not what the books tell you, etc.
The fact that when gases freeze/liquefy, they massively reduce in volume and when they boil/sublimate, they massively expand.
I know this from own personal experience of dealing with cryogenic gases, primarily liquid nitrogen and dry ice.
Likewise, how reducing the pressure lowers the boiling point, and makes things far more likely to be a gas, vs increasing the pressure which increases the boiling point and makes things more likely to be a solid or a liquid.
Again, this is from personal experience, such as that obtained when using a pressure cooker, or a rotary evaporator, or a vacuum oven/vacuums in general.
Likewise, my experience of using electron microscopes shows quite clearly that low pressure is not just a case of molecules expanding, and instead gases have very large voids between the individual molecules. Voids which electrons can freely pass through, while introducing large amounts of air prevents that. The same applies even more to mass spectrometers, and instruments which use ion beams. These instruments need very low pressures to operate as they rely upon the ions being able to freely travel in a straight line without colliding with the air.
Your magically expanded molecules would prevent it all from working.
Yet you want to pretend an extreme low pressure causes the gas to freeze.
Even when there is nothing to transfer its energy to to cause it to freeze.
And then you want that magically expanded gas in an extreme low pressure environment to be magically massive to form a solid, impenetrable wall.
And that is just for this thread.
For the other thread there is plenty more.
You know how you have snow on high mountains, even in sunlight and the same sunlight at sea level makes you hot.
That is due to the sunlight providing additional energy to that which is already there.
The sunlight is absorbed over a very large area near ground level.
This means a lot of energy is being absorbed, and thus the overall temperature will be higher.
Conversely, on the top of a mountain, only a small portion of the area has land to absorb the sunlight, with most of it just passing straight through the air to get lower. That means overall there is less energy being absorbed and thus the overall temperature is lower.
That is then combined with the overall thermal mass.
Lower down, especially near the ocean, you have a very large thermal mass, which during the night will slowly radiate away that energy, keeping the temperature still fairly warm for when the sun next comes out.
Conversely, high on a mountain, you typically have a lot less thermal mass and thus far more of the energy can be radiated away during the night, lowering the overall temperature.
You then have the positive feedback loop of albedo.
Snow is quite reflective, and thus reflects/scatters a lot of the energy from the sun away from the ground so it isn't absorbed, whereas black asphalt and other dark grounds absorb a lot more.
The sun still imparts the same amount of energy per unit area at both locations (technically the higher altitude has slightly more).