November 21, 2020

JonAstroTech

Tech Content Simplified

What is a light year and where it is used

The speed of light

In this article we read about what is a light year and how do we measure the distance of celestial objects.

In vacuum light travels at 299792458 meters per second.  Wait ! That number is not even readable, to put it in a better perspective it is 299792 kilometres per second

So one can say light travels @ 2.99 lakh kilometres per second
(186k miles per second)

Now we multiply distance traveled by light for a minute and then into hours, days, months and finally for an entire year.The total distance traveled by the light in a year will be a number which you won’t bother to read.

Just know that its a very very huge number close to 9.5 trillion kilometres also called as One Light Year

What is a light year and where it is used

Why do we need it

We cannot measure the distance between two stars in kilometres. That will be ridiculous.

The closest star to our Sun is Proxima Centauri which is 4.5 light years away. You got it right it will take 4.5 years to reach this star if we ever travel at the speed of light. In general, Light Year helps us to measure the distance in space at ease

Fun Fact: If this Proxima Centauri star explodes right now, it will take another 4.5 years for us to see it in action in our telescopes from earth! Because only then its light would have reached earth to witness the explosion.

Few mind blowing numbers in light years which lets us know how vast is our Universe

Jonathan Ebenezer

Share This Article :