Why the moon doesn rotate on itself?
The moon does rotate. It rotates with the same period or frequency as it revolves around the earth. If it didn’t, we would be able to see both sides of it, the other side showing when it was halfway around the earth. Imagine that you are facing north, and somebody is right in front of you, facing you (he is facing south), holding a surprise behind him that you can’t see. Now imagine that person walking around you in a circle (orbiting you). You get to turn (rotate on your axis) to watch him go around you in the circle. If he doesn’t turn (rotate) while revolving, when he gets halfway, you’ll see him from behind and see what he’s holding. He has to slowly turn around once while walking the circular path in order to keep his “dark side” invisible to you.
