How many kilometers are 120 light years? How many kilometers are 40 light years? Let's find out together about a light year to find the answer!
Surely all of us have heard of the light year unit. This is a unit of measurement commonly used when talking about the distance between stars or planets in the universe.
When we use powerful telescopes to observe distant objects in space, we are actually looking back into the past. How is this possible?
Light travels at 186,000 miles (or 300,000 kilometers) per second. This may seem fast, but objects in space are so far away that it takes a long time for their light to reach us. The farther away an object is, the farther back in time it appears to us.
The Sun is the closest star to us. It is about 93 million miles away. So it takes about 8.3 minutes for light from the Sun to reach us. This means that we always see the Sun as it was about 8.3 minutes ago.
The next closest star to us is about 4.3 light years away from Earth. So when we see this star today, we are actually seeing it as it was 4.3 years ago. All the other stars we can see with the naked eye are much farther away, some even thousands of light years away.
So can a bright year be converted to km? So how to convert, please read the article below to see the results.
The light-year is most commonly used to express distances to stars or to larger galactic distances, especially for the general public and in popular scientific publications. The unit of measure commonly used in astrometry is the parsec (symbol: pc, equal to about 3.26 light-years; this is the distance at which an astronomical unit appears to be viewed with an angle of one arcsecond).

Light is something that travels very fast, its speed is 300,000km/s, which we cannot see with our naked eyes.
A light second is the distance light travels in 1 second, and a light year is the distance light travels in 1 year.
According to convention, a light year is calculated as follows:
- 1 light second = distance in 1 second x number of seconds in a year
- One year = 31,556.26 seconds
So,
A light year is the distance light travels in one year, how far is it? Take the distance in one second and multiply it by 31,556,926 – the number of seconds in a year – and the result is 9.4605284 × 10 to the 12th power kilometers, or about 9.5 trillion kilometers.
A light second is the distance light travels in one second – that is, 7.5 times the distance around the Earth's equator.
Light year is a common unit of measurement in the vast universe. Because of the word “year”, people often mistakenly think that this is a unit of time. However, this is a unit of distance. This is also a common question in TV shows that makes players easily confused.
Above, we have shared information about how many kilometers a light year is, how many earth years, hope you have useful information and knowledge.