what is a light year?

Answer 1

It is the distance travelled by light in 1 year.

Answer 2

A light-year is approximately equal to

9,460,528,404,879 km (about 9.461 Pm)
5,878,482,164,161 statute miles[1]
90,239.7263 AU
The actual, exact length of the light-year depends on the length of the reference year used in the calculation, and there is no wide consensus on the reference to be used. The figures above are based on a reference year of 31,556,925.9747 seconds, but other reference years are often used, such that the light-year is not an appropriate unit to use when extremely high precision is required.

However, the IAU style guide recommends the use of calendar years, specifically Julian (and not Gregorian) calendar years of 365.25 days or exactly 31,557,600 seconds. This gives the light-year an exact value of 9,460,730,472,580,800 meters, again about 9.461 Pm).

The light-year is often used to measure distances to stars. In astronomy, the preferred unit of measurement for such distances is the parsec, which is defined as the distance at which an object will generate one arcsecond of parallax when the observing object moved one astronomical unit perpendicular to the line of sight to the observer. This is equal to approximately 3.26 light years. The parsec is preferred because it can be more easily derived from, and compared with, observational data. However, outside scientific circles, the term light-year is more widely used.

Units related to the light year are the light-minute and light-second, the distance light travels in a vacuum in one minute and one second, respectively. Since the speed of light is defined as 299,792,458 metres per second, a light-second is exactly 299,792,458 m in length and a light-minute is exactly 17,987,547,480 m. In contrast to the light-year, the lengths of the light-minute and light-second are fixed with 100% precision.

(For a list of lengths on the order of one light-year, see the article 1 E15 m.)

Answer 3

A light-year or lightyear is the distance light travels in vacuum in one Julian year.


A light-year is approximately equal to

* 9,460,528,404,879 km (about 9.461 Pm)
* 5,878,482,164,161 statute miles[1]


Light is incredibly fast but space is incredibly large so scientists decided to measure the distance between planets and other terrestrial bodies in terms of how far light could travel in one year through the vacuum of space.

Answer 4

The distance light will travel in one years time.
about 9.4605284 × 10^15 meters

Answer 5

A light year is a measure of distance in space. It is equal to the distance travelled by light in one earth year, thus equal to 5878482164161 miles.

Since distances are very vast in the universe instead of using ridiculusly long numbers we use light years for ease.

Answer 6

A light year is the distance in wich a beam of light travels in one year. (365 days)

Here is some more information about a light year from Wikipedia:

A light-year is approximately equal to

9,460,528,404,879 km (about 9.461 Pm)
5,878,482,164,161 statute miles[1]
90,239.7263 AU

Answer 7

The distance that light travels in one year. It's a measurement for distance, not time, despite the name.

Answer 8

A light-year or lightyear, symbol ly, is the distance light travels in vacuum in one Julian year.

A light-year is approximately equal to

9,460,528,404,879 km (about 9.461 Pm)
5,878,482,164,161 statute miles[1]
90,239.7263 AU

Answer 9

it is a distance measurement - the distance that light can travel in a year.

Answer 10

the amount of Distance that light can travle in a Straight line in one year