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.

May 28, 2020 · The light year or light-year (ly) is a unit of length that is the distance light travels in a vacuum in one Earth year. One light year is exactly 9460730472580.8 km (approximately …

Dec 16, 2024 · A light year is a measure of distance equivalent to how far light travels in one single Earth year. It’s a fundamental unit for expressing astronomical distances, crucial for …

May 3, 2025 · What Is a Light Year, Really? Let’s begin with the basics. A light year is the distance that light travels in a vacuum in the span of one Earth year.

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 …

May 18, 2025 · A light-year measures the distance light travels in one year, approximately 9.46 trillion kilometers. Light moves at 299,792 kilometers per second, covering this vast distance in …

A light-year (ly) is the distance that light can travel in one year. In one year, light travels about 5,880,000,000,000 miles or 9,460,000,000,000 kilometers. So, this distance is 1 light-year. For …

Oct 1, 2024 · But what exactly is a light-year, and why is it so useful for astronomers? A light year is a measure of distance similar to a mile or a kilometer. A light year is the distance that light …

Dec 5, 2016 · The meaning of LIGHT-YEAR is a unit of length in astronomy equal to the distance that light travels in one year in a vacuum or about 5.88 trillion miles (9.46 trillion kilometers).