What I learned was that the atmosphere has layers, the first layer is named Troposphere, the second layer is called the Stratosphere, the 3rd layer is called the Mesosphere, the forth and last layer is called the Troposphere.
The Troposphere is the layer that we live in this is also were weather occurs and 90% of mass if found here too.
Next is the Stratosphere which is above the Troposphere, this layer to start with gets cold at first then in gets hotter and the ozone layer is found here too. Also this layer protects us from the sun.
Next is the middle layer, Mesosphere this layer protects us for mediators and it starts to get cold too.
Last layer is called the Themosphere this is were the norther lights happen, there's not a lot of oxygen or pressure ether and this is also the hottest layer too.