A light-year, alternatively spelled light year (ly or lyr[3]), is a unit of length used to express astronomical distances and is equal to exactly 9 460 730 472 580.8 km, which is …

Sep 25, 2025 · A light-year is the distance light travels in one Earth year. Learn about how we use light-years to measure the distance of objects in space.

Jan 1, 2025 · Light is the fastest-moving stuff in our universe. It travels at 186,000 miles per second (300,000 km/sec). So, a light-year is 5.88 trillion miles (9.46 trillion km). However, stars …

How many miles are in a light year? Use this easy and mobile-friendly calculator to convert between light years and miles. Just type the number of light years into the box and hit the …

Light is the fastest thing in our Universe traveling through interstellar space at 186,000 miles/second (300,000 km/sec). In one year, light can travel 5.88 trillion miles (9.46 trillion km). …

May 28, 2020 · A light year (ly) is the distance light travels in one Earth year. It is 9.4607×10 15 meters or 5.8786×10 12 miles, about 63 astronomical units or about 0.3 parsecs.

May 26, 2025 · A light-year is the distance light travels in a vacuum over the course of one year. Multiply the speed of light by the number of seconds in a year, and you get the magic number: …

Oct 24, 2025 · Light-year, in astronomy, the distance traveled by light moving in a vacuum in the course of one year, at its accepted velocity of 299,792,458 metres per second (186,282 miles …

Dec 15, 2024 · A light-year is the distance light travels in one year. Light moves incredibly fast — about 186,000 miles (300,000 kilometers) per second, covering 5.88 trillion miles (9.46 trillion …

A light year, used in astronomy, measures the distance light travels in a year—about 9.46 trillion kilometers or 5.88 trillion miles.