# How and why light-years are used to measure distances in the universe?

##### 1 Answer

Jan 8, 2016

A type of scientific notation used in place of extremely large numbers.

#### Explanation:

1 light years equals 5,879,000,000,000 miles; the distance light travels in one years. Considering astronomers have placed the size of our universe at approximately 45 billion light years it makes for a much smaller and more comprehendible number than 45 billion times 5,879,000,000,000 to get the number equal to the approximate size of our universe.