mesosphere

A layer of the atmosphere located between the stratosphere and the thermosphere, spanning approximately from 50 to 80 kilometers of altitude. Within it, temperature decreases with height, reaching a value on the order of –80°C at its upper part (mesopause). In the mesosphere the air is highly rarefied. It contains only 0.1% of the total mass of the atmosphere. In addition, in its upper part the gaseous molecules begin to be dissociated into ions, which gives rise to the atmospheric region known as the ionosphere.