A light-year is a unit of astronomical distance, representing the distance that light travels in one year.

1000 kilometers is an extremely small fraction of a light-year, approximately 0.0000 light-years.

This is because a light-year is an enormous distance, covering trillions of kilometers, while 1000 kilometers is a terrestrial scale distance.

Kilometers are used for everyday distances on Earth. Light-years are used for vast distances in space between stars and galaxies.