Mesosphere

Layer of the atmosphere directly above the stratosphere and below the thermosphere

The mesosphere (from Ancient Greek μέσος (mésos) 'middle' and -sphere) is the third layer of the atmosphere, directly above the stratosphere and directly below the thermosphere. In the mesosphere, temperature increases with height (due to particle velocity), but the average temperature decreases as altitude increases. This characteristic is used to define limits,: it begins at the top of the stratosphere (sometimes called the stratopause), and ends at the mesopause, which is the coldest part of Earth's atmosphere, with temperatures below −143 °C (−225 °F; 130 K).

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