What is the Exosphere?

The exosphere (700 to 10,000 km (440 to 6,200 miles)) is the outermost layer of the atmosphere. It extends from the top of the thermosphere to about 10,000 kilometers above Earth’s surface. The exosphere is made up of very thin air heated by the Sun. This layer contains most of the atmosphere’s hydrogen and helium.

Exosphere facts

• The exosphere is the outermost layer of the Earth’s atmosphere.
• It starts about 10,000 kilometers above the Earth’s surface and extends to about 100,000 kilometers.
• The exosphere is very thin, with only a few particles per cubic meter.
• The exosphere contains mostly hydrogen and helium.
• The exosphere is where the Earth’s magnetic field interacts with the solar wind.