The stars in the Big Dipper are all different distances from Earth, which affects the time it takes the light to travel. The constellation's most distant is Alkaid; its light takes 210 years to reach Earth. From Megrez, the closest star, the light takes 63 years to each Earth.
The distance between Earth and the stars is measured in light years, which is the distance light travels through space in one year. Other than Alkaid and Megrez, the other stars in the Big Dipper are 68, 78, 88, 90 and 105 light years away. These distances correspond to the number of years it takes for each star's light to reach Earth.