Earth & SkyGreek → English
Heliopause
/ˈhiːlioʊpɔːz/noun
The boundary where the solar wind is halted by interstellar gas.
The Greek roots
ἥλιος
hḗlios
sun
παῦσις
paûsis
a stopping, ceasing
Literally: “where the sun stops”
The story of the word
Both halves are Greek, including the pause, which reaches English through Latin pausa from παῦσις. The name was coined in the 1960s for a place nobody could locate. Voyager 1 crossed it in August 2012 and reported it not as a wall but as a sudden jump in the density of the plasma around the spacecraft.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 1960s
Same family
pausemenopauseheliumaphelion
In a sentence
Past the heliopause the instruments were reading interstellar space directly.