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

500,000 yards is approximately 457.2 kilometers.

This conversion is primarily for understanding the vast difference in scale between terrestrial measurements and cosmic distances. It's not a practical measurement used in everyday life or standard astronomy.

No, 500,000 yards (or 457.2 km) is an extremely short distance on a cosmic scale. It's less than the diameter of Jupiter and a tiny fraction of a light-year.