Thermosphere
Thermosphere, region of increasing temperature in Earth’s atmosphere that is located above the mesosphere. The base of the thermosphere (the mesopause) is at an altitude of about 80 km (50 miles), whereas its top (the thermopause) is at about 450 km.
This article was most recently revised and updated by John P. Rafferty.
Citation Information
Article Title:
Thermosphere
Website Name:
Encyclopaedia Britannica
Publisher:
Encyclopaedia Britannica, Inc.
Date Published:
11 November 2026
Access Date:
November 14, 2026