exosphere
/ˈɛksoʊsfɪɚ/noun
exosphere is spelled E-X-O-S-P-H-E-R-E: 9 letters. It appears about once in every 30 million words in written English, the 165,739th most frequent word form (wordfreq, 2021 data). As a noun, exosphere means “the uppermost layer of a planet's atmosphere” (English Wiktionary, September 2026). The plural of exosphere is exospheres.
How many letters and syllables are in exosphere?
| Letters | 9: E-X-O-S-P-H-E-R-E |
|---|---|
| In writing | about once in every 30 million words; the 165,739th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is exosphere?
Exosphere appears about once in every 30 million words in written English, the 165,739th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce exosphere?
- UK /ˈɛksəʊsfɪə/
- US /ˈɛksoʊsfɪɚ/
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Rho9998-exosphere.wav, Wikimedia Commons (author and licence on each file's page).
Forms of exosphere
- exospheres plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does exosphere mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
the uppermost layer of a planet's atmosphere
- 2
an extremely thin atmosphere, as on Saturn's moon Dione
"Scientists weren't even sure Dione would be big enough to hang on to an exosphere" ('Cassini Detects Hint of Fresh Air at Dione', , JPL, Mar. 02, 2012)
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Exosphere in Spanish, French, German and Portuguese
In the sense the uppermost layer of a planet's atmosphere:
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does exosphere come from?
From exo- + -sphere.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).