Not really a spoiler, but in the movie Interstellar there was a planet that had frozen clouds. Is this actually possible? I know ice is less dense than water and so can float, but I'm having a hard time maintaining suspension of disbelief in this case as you would need a solid that was less dense than a gas AND was solid at the same temperature as the gas.
[Physics] Is it possible to have frozen clouds floating in the sky
atmospheric sciencethermodynamicsweather
Best Answer
Yes, there are high-altitude clouds made of ice crystals, for example cirrus clouds. You do not need to fulfill any condition of having a lower density than surrounding air, much like regular clouds (composed of water droplets) do not require the density of water to be lower than that of air. The trick is that the individual droplets or crystals are so small that they do not fall at a significant speed (which can be 100 mph updrafts in the center of thunderstorm clouds, supporting huge hail-like balls of ice).