What Is The Atmosphere?
It is the presence of oxygen in the atmosphere which allows living things to breathe and which protects the Earth from the rays of the sun by maintaining the right temperature.
The atmosphere is about 1,000km thick and is divided into five layers, which have different characteristics.
The layer nearest to the Earth's surface is called the troposphere, from the Greek word tropos which means 'movement'.
This is the most turbulent layer and is where our weather comes from.
The gases which make up the atmosphere become thinner and thinner the higher up they are, before reaching Outer Space.
The troposphere is in contact with Earth's surface. Here, the air is composed of nitrogen, oxygen, carbon dioxide and thin gases and water vapour.
This is where the wind, the rain and snow begin. In the higher zone of the tropozone the temperature reaches about -70C.
— Credit: The Big Book of Knowledge.