how old is the
light from the stars?

When you look at the night sky, the light hitting your eye at that moment actually left those stars hundreds of years ago. For example, Gamma Aries, one of the stars in the Aries constellation, is approximately 164 light years away, meaning the light you see tonight left that star in 1854.

So, when you look at the rest of the constellations, how far back in time are you looking?

HoverClick on the stars below for more information.