The Atmosphere (atmos-air; sphere-orbit, area) atmosphere can be compared with the skin of the lemon or an onion with many spherical layers.It also acts as a blanket that makes life possible on the earth by regulating temperature, absorbing toxic gaseous wastes, filtering harmful solar rays and facilitating water cycle.The thin layer of gases that envelops the Earth is held in place by the planet's gravity, Dry air consists of approximately 78% Nitrogen, 21% Oxygen, 1% Argon and other inert gases.It is a complex mixture of a number of gases, water vapours and a variety of fine particulate material ???????????????