The Moon is our closest neighbor in space, and the only other world on which we humans have walked. It is a world with a fascinating history. Locked into a synchronous orbit, one side of the moon is forever facing the Earth.
The Moon is 27 % the size of the Earth, having a diameter of 3476 km. The average density is 3.36 g/cm3, less than Earth but still quite high. The Moon is also a cold world, with a temperature range of between -170 C to 130 C.
We have had several chances to explore the moon and have returned over 800 lbs of samples to study. Scientists believe they have a pretty good understanding of the Moon but there are still some questions whose answers might require a return to this strange world.
Copyright © 1997 Kathy A. Miles and Charles F. Peters II