Definition, Meaning & Synonyms
light-year
noun
/ˈlaɪt jɪr/
Definition
A unit of distance that represents how far light travels in one year.
Examples
- The closest star system to Earth, Alpha Centauri, is about 4.37 light-years away.
- The galaxy is estimated to be over 100,000 light-years across.
- When discussing distances in space, astronomers often use light-years instead of kilometers or miles.
Meaning
Used in astronomy to measure vast distances between celestial objects.
Synonyms
- astronomical unit
- parsec (for larger distances)
