My mum plays lawn bowls. One of the aims of the game is to bowl the large ball as close as you can to the kitty or jack (smaller white ball). At times things can get close & a measuring tape is utilised to see who is the closest.
Similarly, measurements can also be applied to the distance between the earth & the moon. The moon is moving further away from the earth each year.
“The moon is slowly receding from earth at about 1½ inches (4 cm) per year, and the rate would have been greater in the past. But even if the moon had started receding from being in contact with the earth, it would have taken only 1.37 billion years to reach its present distance. This gives a maximum possible age of the moon—not the actual age. This is far too young for evolution (and much younger than the radiometric ‘dates’ assigned to moon rocks)”.http://creation.com/how-old-is-the-earth.