Water can remain liquid at temperatures well below the freezing point if there is no surface or impurity for the water to freeze onto
. If these droplets freeze on aircraft wings, they disrupt the movement of air that gives the aircraft lift.
Water molecules ejected by rare cometary impacts on the Moon might freeze onto
these "cold traps." Or perhaps hydrogen from the solar wind could combine with oxygen atoms in the lunar regolith (dust and rock) and form water molecules--some of which, over the eons, could find their way to the cold traps.
In the absence of sunlight, atmospheric gases freeze onto
the moon's surface and electrons have fewer particles with which to collide, Geissler's team explains.
With further extraction of the heat through this shell of solid metal, the liquid begins to freeze onto
it, and the wall of solid increases in thickness.
As the crystals move around the cloud, more droplets of water attach and freeze onto
the original crystal.
These gases would drift across the Moon and freeze onto
the cold surface of the night side.