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
Origin and Etymology of thermosphere
International Scientific Vocabulary
First Known Use: circa 1950
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