light-year, alternatively spelled lightyear, is a unit of length used to express astronomical distances and is equivalent to about 9.46  kilometers (9.46×1012 km) or 5.88  miles (5.88×1012 mi).

As defined by the  Astronomical Union (IAU), a light-year is the distance that light travels in  in one Julian year (365.25 days).

Because it includes the “year”, the term light-year is sometimes misinterpreted as a unit of time.

Last Updated on 2 years by pinc