The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere and thermosphere. A further region at about 500km above the Earth's surface is called the exosphere. Mesosphere lies above the stratosphere. It extends upward to a height of about 85km above the Earth. Most meteors burn up in the mesosphere. Here the temperature decreases with height, reaching a minimum of about 90°C at the mesopause (boundary between the mesosphere and the thermosphere) which makes it the coldest place on the Earth.