Question #ee778

1 Answer
Jan 25, 2018

Very low density layer of air with very high molecular speed.


The thermosphere (from the Greek word "thermo" meaning heat) is a layer of our planet atmosphere extending above 100 km of altitude up to 600 km of altitude.

It is composed by very few molecules of air (extremely low density) that move very fast. For this reason its kinetic temperature is up to 2,500 Celsius but, because of the low density, heat is not transferred and therefore it is a very cold place despite its temperature.

The aurora (northern lights) are generated in the thermosphere by the impact of high-energy particles from space (mostly from the solar wind) with the atoms and molecules of the thermosphere at the higher latitudes (close to the Earth's poles).

The International Space Station and other satellites orbit within the thermosphere.