The exosphere is the outermost layer of the atmosphere. It is very thin, and it extends from about 500 km to 10,000 km. The exosphere is made up mostly of hydrogen and helium, and it is very hot.

Thermosphere

The thermosphere is the second outermost layer of the atmosphere. It extends from about 90 km to 500 km. The thermosphere is made up mostly of oxygen and nitrogen, and it is very hot.

Mesosphere

The mesosphere is the third outermost layer of the atmosphere. It extends from about 50 km to 90 km. The mesosphere is made up mostly of oxygen and nitrogen, and it is very cold.

Stratosphere

The stratosphere is the fourth outermost layer of the atmosphere. It extends from about 10 km to 50 km. The stratosphere is made up mostly of ozone and nitrogen, and it is very warm.