# What distances do a light-year and astronomical unit represent?

## What distances do a light-year and astronomical unit represent?

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 × 1012 km (5.87863 × 1012 miles), or 63,241 astronomical units.

## What is the distance difference between AU & light-year?

One light year is almost six trillion miles. And an astronomical unit is the average distance between the earth and the sun. So the distance to the sun is by definition one AU. A parsec is the distance at which one astronomical unit subtends an angle of one second of arc.

**How far does light travel in one year this distance is known as a light-year Ly and is used in measuring astronomical distances?**

six trillion miles

A light-year is how astronomers measure distance in space. It’s defined by how far a beam of light travels in one year – a distance of six trillion miles. Think of it as the bigger, badder cousin of the inch, the mile, the kilometer, and the furlong.

### How long does it take to travel a light year?

One light-year is 5.87849981 × 10 12 miles. (That’s 5,878,499,810,000 miles, or nearly 6 trillion miles). So, it would take New Horizons 18,449 years to travel one light year.

### How fast in mph is a light year?

A light year is a measurement of distance. This distance is measured by how far light can travel in a year. Light travels at approximately 186,000 miles per second. In one year (365.25 days) that is equivalent to 5,869,713,600,000 miles.

**How far does light travel in a year?**

But how far does light travel in a year? Basically, it moves at a speed of 299,792,458 meters per second (1080 million km/hour; 671 million mph), which works out to about 9,460.5 billion km (5,878.5 billion miles) per year. Calculating the speed of light has been a preoccupation for scientists for many centuries.

#### How many Earth years is a light year?

A light year is not a measure of time. It’s a measure of distance. 11,000 light years is the distance light travels in 11,000 Earth years.