What is one light year defined as?

A light year is defined as the distance that light travels in one year. This measurement is based on the speed of light, which is approximately 299,792 kilometers per second (or about 186,282 miles per second). Since light travels at such an incredibly fast rate, the distance it covers in a year becomes a very large number, making it useful for expressing astronomical distances. For instance, one light year is about 9.46 trillion kilometers (or about 5.88 trillion miles).

Understanding this concept is crucial in fields such as astronomy, where distances between stars and galaxies are so vast that kilometers or miles would become unwieldy measurements. Therefore, using a light year provides a more manageable way to communicate and understand these distances in space.