The mesosphere is the third layer of the Earths atmosphere, located directly above the stratosphere and directly below the thermosphere. It extends from about 50 to 90 km above the Earths surface. The exact upper and lower boundaries of the mesosphere vary with latitude and season, but the lower boundary is usually located at altitudes from 47 to 51 km above sea level, and the upper boundary (the mesopause) is usually from 85 to 100 km. The mesosphere is characterized by extremely low air pressure and temperatures that can drop as low as -90 degrees Celsius (-130 degrees Fahrenheit) . Some key features of the mesosphere include:

• Temperature: Temperature decreases with height in the mesosphere, and it is the coldest part of the Earths atmosphere.

• Composition: The gases in the mesosphere are all mixed up rather than being layered by their mass.

• Phenomena: The mesosphere is the layer of the atmosphere where meteors burn up and streak across the sky during meteor showers.

The mesosphere is an important layer of the Earths atmosphere, and scientists study it to better understand the dynamics of the atmosphere and its interactions with space.