The mesosphere extends from the stratopause to 80–85 km. Most meteoroids get burnt in this layer.
Temperature decreases with height in the mesosphere. The mesopause, the temperature minimum that marks the top of the mesosphere, is the coldest place around Earth and has an average temperature around −85 °C. At the mesopause, temperatures may drop to −100 °C. Due to the cold temperature of the mesosphere, water vapour is frozen, forming ice clouds. These clouds are called noctilucent clouds. This implies that the noctilucent clouds are the highest clouds in the Earth’s atmosphere, located in the mesosphere at altitudes of around 76 to 85 kilometers (47 to 53 mi). They are normally too faint to be seen, and are visible only when illuminated by sunlight from below the horizon while the lower layers of the atmosphere are in the Earth’s shadow. Noctilucent clouds are not fully understood and are a recently discovered meteorological phenomenon.
Mesopause, a thin layer of extremely cold atmosphere, separates the mesosphere from the Ionosphere above.