exosphere
noun
exo·sphere
ˈek-sō-ˌsfir 
: the outer fringe region of the atmosphere of the earth or a celestial body (such as a planet)
Examples of exosphere in a Sentence
Recent Examples on the Web
Landings can also release water vapor, carbon dioxide and other gases into the lunar exosphere – an extremely thin layer of atoms hovering above the surface – and create a temporary atmosphere.
—
Parvathy Prem,
The Conversation,
14 May 2026
The next step is to try and figure out what the composition of the exosphere is, a task ideally suited to the James Webb Space Telescope.
—
Keith Cooper,
Space.com,
5 May 2026
Orbits of the Earth ultimately decay, as faint traces of the exosphere produce drag, causing a circling object eventually to plunge into the atmosphere and incinerate.
—
Jeffrey Kluger,
Time,
14 Nov. 2025
Its thin exosphere offers almost no protection from solar radiation, making this twilight boundary a literal knife-edge of danger.
—
Kaif Shaikh,
Interesting Engineering,
13 Nov. 2025
See All Example Sentences for exosphere
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Parvathy Prem,
The Conversation,
14 May 2026
The next step is to try and figure out what the composition of the exosphere is, a task ideally suited to the James Webb Space Telescope.
—
Keith Cooper,
Space.com,
5 May 2026
Orbits of the Earth ultimately decay, as faint traces of the exosphere produce drag, causing a circling object eventually to plunge into the atmosphere and incinerate.
—
Jeffrey Kluger,
Time,
14 Nov. 2025
Its thin exosphere offers almost no protection from solar radiation, making this twilight boundary a literal knife-edge of danger.
—
Kaif Shaikh,
Interesting Engineering,
13 Nov. 2025
See All Example Sentences for exosphere
Cite this Entry
“Exosphere.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/exosphere. Accessed 5 Jul. 2026.
Copy CitationKids Definition
exosphere
noun
exo·sphere
ˈek-sō-ˌsfi(ə)r
: the outermost region of the atmosphere of the earth or a planet
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