Because that's how it is defined. A light-year is the distance that light travels in a year.
Stars are not measured in light years. The distance between them is.
light years.
Light Years.
in light years
light years
Light years or Parsecs
'Light-year' is a unit of a distance. It is the distance for light to travel one year. So it is a great distance.
Not really. A light year is a measure of distance. It is the distance light can travel in one earth year, about 6 trillion miles
A light year
Distance in space is measured in 'light years' or in 'scientific notation'
It's measured in light-years (or parsecs) which is trillions of miles.
It's measured in light-years (or parsecs) which is trillions of miles.