How long is a lightyear in miles?

Answer 1

A light year is a measure of distance, not speed. The word 'year' seems strange, I know. Asking 'how fast is a light year' is like asking 'how fast is a mile?' In a vacuum, light travels about 186,000 miles in one second. The moon is roughly 240,000 miles away, for comparison. So in one second, light from earth would make it most of the way to the moon! Now let light travel for one full year, and you could figure out how far that is. The distance would be called one light year.

Answer 2

One lightyear is equivalent to about 5.88 trillion miles. It represents the distance that light travels in one Earth year in a vacuum. It is a commonly used unit of measurement in astronomy due to the vast distances involved in space.

Answer 3

A light-year is defined as the distance that light can travel in 1 year. We can calculate this by multiplying the speed of light by 1 year (or 3.1557*10^7 seconds) to find the distance:

d = c*t

=(2.9979*10^8 m/s)*(3.1557*10^7 s)

=9.4605*10^15 meters

or ~9,500,000,000,000 kilometers

or ~5,900,000,000,000 miles

or ~63,279 au

Answer 4

A light year is a measure of distance, not speed. The word 'year' seems strange, I know. Asking 'how fast is a light year' is like asking 'how fast is a mile?' In a vacuum, light travels about 186,000 miles in one second. The moon is roughly 240,000 miles away, for comparison. So in one second, light from earth would make it most of the way to the moon! Now let light travel for one full year, and you could figure out how far that is. The distance would be called one light year.

Answer 5

One light-year is equal to:

exactly 9,460,730,472,580.8 km (about 9.5 Pm)

about 5,878,625,373,183.608 miles (about 6 trillion miles)

about 63,241.1 astronomical units

about 0.306601 parsecs

exactly 31,557,600 light-seconds.

Answer 6

186,000 miles per second

The above is the speed of light in miles. The light year could be computed by multiplying this by 365 x 24 x 60 x 60 seconds.

Answer 7

There are almost 6 trillion miles in a light year.

One light year is 5.87849981 × 1012 miles.

There are almost 10 trillion kilometers in one light year.

(But the basic metric unit of distance is the meter, not the kilometer.)

One light year is 9.4605284 x 1015 meters.

Answer 8

"Light Year" is not a speed. It's a length or distance, just like a foot or a mile or a kilometer. It is the distance that light can travel in one year.

The speed of light is about 186,000 miles (300 million km) per second.

At that rate, the distance in one light-year is about:

5,878,700,000,000 miles ("5 trillion 878 million" etc.)

9,460,890,000,000 kilometers ("9 trillion 460 million" etc.)

(This shows you why it would be tough to use miles or kilometers to talk about distances from earth to stars ... the numbers would be too hard to handle. That's why the 'light-year' was invented.)

You might say the speed of light is 1 light-year per year

Answer 9

A lightyear is a unit of distance.

It's the distance that light would travel (in a vacuum) in one year.

Answer 10

A light year does not move. It is a unit of measurement of how far a light beam would travel in one year. It is about 6 trillion miles.