Snow is generally formed
when water vapor freezes around an impurity high up in the earth's atmosphere at
temperatures below 0 ° C (without first passing liquid form) and then falls to
the earth's surface.
It is formed when water vapor is exposed to very low temperatures and turns to
ice. Depending on temperature, humidity, wind and other physical conditions, ice
crystals can then form in many different versions, such as needles, prisms,