A light-year is the distance light travels in a vacuum in one Julian year (365.25 days). It's a unit of astronomical distance.

There are approximately 3.107 x 10^13 feet in one light-year. So, 500,000 feet is a minuscule fraction of a light-year.

Astronomers use light-years because the distances between celestial objects are so vast that using feet would result in astronomically large and impractical numbers.

No, 500,000 feet (which is about 94.7 miles) is an extremely small distance when compared to the vast scales of space measured in light-years.