The Solar Neighbourhood

The solar system is so large that we can measure distance according to how long it takes the light from the object to reach us.  This has ramifications that we do not often realise.  For example, the light from the Sun takes 8.5 minutes to reach us.  That means every time we look at the Sun, we are seeing it as it was 8.5 minutes ago.  The nearest star, after the Sun, is Proxima Centauri, is 4.24 light years.  That means when we look at the star, we see it as it was 4.24 years ago.  For celestial objects that are more distant, millions of light years or more, they might not even exist any longer.