A light-year is the distance that light travels in one year. It's a unit used to measure astronomical distances.

A million miles is approximately 0.0000 light-years. This shows how incredibly vast a light-year is compared to a million miles.

Astronomers use light-years because the distances in space are so enormous that using miles would result in extremely large and unmanageable numbers.

While a million miles is a very long distance on Earth, it's a tiny fraction of a light-year and insignificant when discussing interstellar space.