ther·​mo·​sphere ˈthər-mə-ˌsfir How to pronounce thermosphere (audio)
: 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
thermospheric adjective

Examples of thermosphere in a Sentence

Recent Examples on the Web A number of satellites, as well as the International Space Station, are actually whizzing around in a layer of the atmosphere called the thermosphere. Breanna Draxler, Discover Magazine, 15 Nov. 2012 But given the likelihood humanity will long be Earth-bound, trips into the thermosphere and beyond create incredible opportunities to explore space while at the same time making the Earth a better place by creating new, otherwise unattainable knowledge that advances the field of medicine. Lisa Suennen, STAT, 26 Sep. 2021 The thermosphere contains the point that most international space programs consider the start of space — the Kármán Line — at 62 miles above sea level. Emilie Le Beau Lucchesi, Discover Magazine, 17 Nov. 2022 But up in the thermosphere, things are much different. Breanna Draxler, Discover Magazine, 15 Nov. 2012 The resulting interactions between the particles and a layer of the upper atmosphere, called the thermosphere, create the famous northern and southern lights. Kate S. Petersen, USA TODAY, 6 Aug. 2022 British billionaire Richard Branson inaugurated a new era by traveling to the thermosphere using his Virgin Galactic venture. Jon Sindreu, WSJ, 25 Feb. 2022 The billionaires had locked themselves in a dude-bro cold war, each eager to make history as the very first head of a space tourism brand to hurl himself into the thermosphere. Boone Ashworth, Wired, 18 July 2021 Amateur traders quickly embraced a company that aims to charge $250,000 for a few minutes of weightlessness in the lower thermosphere. Jon Sindreu, WSJ, 11 May 2021 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'thermosphere.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary

First Known Use

circa 1950, in the meaning defined above

Time Traveler
The first known use of thermosphere was circa 1950

Dictionary Entries Near thermosphere

Cite this Entry

“Thermosphere.” Dictionary, Merriam-Webster, Accessed 3 Oct. 2023.

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