What is the light year? How many kilometers is a light year?

When it comes to the distance of other Sun stars in our sky, people do not use miles or kilometers, but use a unit of measurement called Light years. Light is the fastest moving thing in the universe, it goes at a speed of 300,000 kilometers per second - very fast. If you can go at the speed of light, then it only takes you 1 second to get around the Earth equator 7.5 times.

1. What is the light year?The light year is the distance the light can travel for a year.
2. How many kilometers is a light year?A light year is equal to 9,460,528,400,000 km (9.5 trillion km), ie 5,878,499,810,000 miles.

The Orion Nebula (or Messier 42) belongs to the constellation of Orion, which is a nebula about 1.34 light-years away.

A second of light is the distance that light travels in a second - that is, 7.5 times the distance of the equator Earth. And a Light Year is the distance that light can travel in a year, how far is it? Take the number of distances in a second multiplied by 31.556.926 - that is, the number of seconds in a year, resulting in 9.4605284 × 10 powers of 12 kilometers, or about 9.5 trillion kilometers.

The number is big, but it's hard to imagine how big this number is. In the 20th century, astronomer Robert Burnham - the author of the Burnham's Celestial Handbook (Burnham's Celestial Handbook) devised a way to describe the distance of a light year. He compressed the Light Year down to Astronomical Unit - the distance between Earth and the Sun , this distance is about 150 million km - equivalent to 8 minutes of light .

A coincidence, the number of astronomical units in a light year is equal to the number of inches in a mile , that is, in a light year there are 63 thousand astronomical units and in a mile of 63 thousand inches. This coincidence makes it easy to imagine how far the Light Year is, now the distance from Earth to the Sun will be 1 inch. So our closest star - Alpha Centauri, 4.4 light-years away, will have a distance of 4.4 miles (7km).