Le site de vulgarisation scientifique de l’Université de Liège. ULg, Université de Liège
Light year

In astrophysics a light year is a unit of distance. It corresponds to the distance covered by light in a year. As light travels at a speed of around 300,000km/s, a light year is the approximate equivalent of 9,500 billion kilometres. 


© 2007 ULi�ge