noun
exosphere
EK-soh-sfeer
Exosphere (noun) means the uppermost layer of a planet's atmosphere. Example: “The exosphere is the outermost part of the atmosphere.”
noun
1
The uppermost layer of a planet's atmosphere.
"The exosphere is the outermost part of the atmosphere."
"Scientists study the exosphere to learn how a planet's air thins out."
"A planet's exosphere is very thin."
2
An extremely thin atmosphere, such as the one found around Saturn's moon Dione.
"Dione has an exosphere rather than a thick atmosphere."
"Some moons have only an exosphere."
"Researchers have detected a thin exosphere around Dione."
How to use exosphere
Learner’s notesIn plain EnglishThe very top layer of a planet's atmosphere, or a very thin atmosphere.
When to use it
It is a scientific term used mainly in astronomy and atmospheric science.
Common pairings
Earth's exosphere
a thin exosphere
the exosphere of a moon
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The _____ is the outermost part of the atmosphere.
Etymology
The word is built from the prefix exo- and the suffix -sphere.
Rhymes for exosphere
See all rhymes for exosphere →Frequently asked questions
What is the exosphere?
It is the uppermost layer of a planet's atmosphere.
Can a moon have an exosphere?
Yes. The word is also used for an extremely thin atmosphere, such as the one around Saturn's moon Dione.
How do you pronounce exosphere?
The stress falls on the first syllable, so it is EK-soh-sfeer.
What is the meaning of exosphere?
"exosphere" (noun) means the uppermost layer of a planet's atmosphere.
