The atmosphere is a gaseous blanket that covers the Earth. Earth's gravitational attraction keeps it close to the planet's surface. The three primary constituents of the atmosphere are argon, oxygen, and nitrogen.
"The atmosphere is a protective covering of gases that protects all life on Earth by keeping temperatures within a certain range and deflecting harmful solar rays."
Allows the sun's heat to be retained rather of leaking back into space.
Protects life from the sun's damaging radiation.
Plays an important role in the water cycle on Earth.
Aids in the stabilisation of the Earth's climate.
Between the atmosphere and outer space, there is no separation. The atmosphere gradually becomes less thick and denser until it "blends" with the outer atmosphere.