The stars in the Big Dipper are at different distances from Earth, so the light from each takes a different amount of time to reach us. Here's a rough estimate for the travel time of light from some of the main stars in the Big Dipper:

* Dubhe (α Ursae Majoris): About 123 light-years

* Merak (β Ursae Majoris): About 79 light-years

* Phecda (γ Ursae Majoris): About 84 light-years

* Megrez (δ Ursae Majoris): About 81 light-years

* Alioth (ε Ursae Majoris): About 81 light-years

* Mizar (ζ Ursae Majoris): About 78 light-years (Mizar is a double star system, so the distance is based on the brighter star)

* Alkaid (η Ursae Majoris): About 101 light-years

What this means:

* The light we see from Dubhe left that star 123 years ago.

* The light from Merak left that star 79 years ago.

* And so on...

This means that when we look at the Big Dipper, we're actually seeing the stars as they were decades, even centuries ago!