How do you measure light years?
It's 186 thousand miles per second. A light-year is the distance light travels in one year. How far is that? Multiply the number of seconds in one year by the number of miles or kilometers that light travels in one second. It's about 5.9 trillion miles (9.5 trillion km).
Join Alexa Answers
Help make Alexa smarter and share your knowledge with the worldLEARN MORE