The distances to other stars beyond the sun are measured in light-years.

Here's why:

* Vast distances: Stars are incredibly far away. Using familiar units like miles or kilometers would result in extremely large and unwieldy numbers.

* Light's speed: A light-year represents the distance light travels in one year. Light travels at a constant speed of approximately 186,282 miles per second (299,792 kilometers per second).

* Convenience: Light-years provide a more manageable way to express the immense distances involved in astronomy.

While light-years are the most common unit, astronomers also use:

* Parsecs: One parsec is equal to about 3.26 light-years. It's often used in scientific calculations.

* Astronomical Units (AU): One AU is the average distance between the Earth and the Sun. It's more useful for measuring distances within our solar system.