The Earth’s atmosphere is a layer of gases surrounding the blue planet and which is retained by the Earth’s gravity. It reaches over 560 kilometers from the surface of the Earth. It contains about 78% nitrogen and 21% oxygen, trace amounts of other gases, and of course water vapor. The mixture of the above gases is known as air. The atmosphere protects life and health on Earth by absorbing ultraviolet solar radiation, absorbing infra-red radiation, and reducing temperature extremes between day and night.

The atmosphere becomes thinner and fades away into space. Four distinct layers have been identified using vertical thermal characteristics(temperature changes as a function of altitude), chemical composition, movement, and density.There is no definite boundary between the atmosphere and outer space. Three-quarters of the atmosphere’s mass is within 11 km of the planetary surface, the so-called troposphere. The Karman line, at 100 km , is recognized as the boundary between atmosphere and space.

With the use of satellites, we are able to get a better view of our atmosphere, one of the component of the earth’s climate system.

Life on Earth is supported by the atmosphere, solar energy, and our planet’s magnetic fields.