Definition of thermosphere
: the part of the earth's atmosphere that begins at about 50 miles (80 kilometers) above the earth's surface, extends to outer space, and is characterized by steadily increasing temperature with height
thermosphericplay \ˌthər-mə-ˈsfir-ik, -ˈsfer-\ adjective
Recent Examples of thermosphere from the Web
Richard Branson licensed the technology for Virgin Galactic, his space tourism gambit, which aims to start regular visits to the thermosphere by 2012.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thermosphere'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of thermosphere
International Scientific Vocabulary
First Known Use: circa 1950
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