Define atmosphere.

The earth is surrounded by a layer of gases called the atmosphere. The atmosphere is very important to life on Earth and does many things to help protect life and help life to survive. The atmosphere protects Earth like a big blanket of insulation. It absorbs the heat from the Sun and keeps the heat inside the atmosphere helping the Earth to stay warm, called the Greenhouse Effect. It also keeps the overall temperature of the Earth fairly steady, especially between night and day. So we don't get too cold at night and too hot during the day.