In meteorology, a cloud is an aerosol consisting of a visible mass of
minute liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar
space.
1 Water or various other chemicals may compose the droplets and crystals. On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture (usually in the form of water vapor) from an adjacent source to raise the dew point to the ambient temperature. They are
seen in the Earth's homosphere, which includes the troposphere, stratosphere, and mesosphere. Nephology is the
science of clouds, which is undertaken in the cloud physics branch of meteorology. There are two methods of naming clouds in their respective layers of the homosphere, Latin and
common.