0 Talk Light-year Edit History Redirected from Lightyear A light-year is a unit of distance measurement based on the travel of light energy, undisturbed in a vacuum, over the course of on Earth year. This article is a stub. You can help our database by fixing it. Read more A parsec is a unit of distance measurement, equal to 3.262 light-years or 19.2 trillion miles.... Parsec An astronomical unit (most often abbreviated AU) is a distance measurement defined as the... Astronomical unit The Roche Limit was a scientific principle. The idea behind the limit was for determining the... Roche limit Related Categories Categories: Memory Beta stubs | Astronomical measurements | Distance measurements Add category