What Is a Light-Year? | NASA Space Place – NASA Science for Kids
网页2024年9月1日 · 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.
Light-year - Wikipedia
网页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 (Scientific notation: 9.4607304725808 × 10 12 km), which is approximately 5.88 trillion mi.
What is a light-year? - Science@NASA
网页Light-year is the distance light travels in one year. Light zips through interstellar space at 186,000 miles (300,000 kilometers) per second and 5.88 trillion miles (9.46 trillion kilometers) per year. We use light-time to measure the vast distances of space.
What is a light-year? | Space
网页2021年12月22日 · A light-year is a measure of astronomical distance: Light travels through a vacuum at precisely 983,571,056 feet (299,792,458 meters) per second, making a light-year approximately 6...
Light-year | Distance, Measurement, Time | Britannica
网页2 天之前 · 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 per second). A light-year equals about 9.46073 × 10 12 km (5.87863 × 10 12 miles), or 63,241 astronomical units.
How Far is a Light Year? | The Fastest Thing in the Universe
网页A light-year is the distance light can travel in one year. 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).
What Is a Light Year? Definition and Examples - Science Notes …
网页2020年5月28日 · The 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 approximately 9.46 trillion kilometers (9.46 x 10 12 km) or 5.88 trillion miles (5.88 x 10 12 mi). The light year is used to describe distances to stars without having to use very large numbers.
What Is a Light-Year? - Live Science
网页2023年6月9日 · A light-year is the distance light travels in a year. Specifically, the International Astronomical Union defines a light-year as the distance light travels through...
Cosmic Distances - NASA Science
网页2020年5月18日 · A light year is the distance a photon of light travels in one year, which is about 6 trillion miles (9 trillion kilometers, or 63,000 AU). Put another way, a light year is how far you'd travel in a year if you could travel at the speed of light, which is 186,000 miles (300,000 kilometers) per second.
What is a light-year? - Cool Cosmos
网页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 example, the nearest star to us is about 4.3 light-years away.