Skymatters: Imagine the far side, not the dark side, of the Moon

"...it’s actually of great interest to astronomers. Having a Moon with one side permanently facing away from us is a huge stroke of luck."

Dark side of the moon

Pink Floyd’s world-renowned album from 1973 titled “The Dark Side of the Moon” was brilliant from a musical perspective, but a little less so from a scientific viewpoint. You see there isn’t a dark side to the Moon. Instead, the Moon has a side which always faces away from the Earth, a side that we never get to see, a side which should more correctly be referred to as the “far side of the Moon”.

It wasn’t always this way, however. When the Moon originally formed, around 4.5 billion years ago, it would have spun on its axis in less than a couple of hours. To an observer on the Earth, they would have seen the Moon’s full surface roughly every two hours. To an observer on the Moon, they would have experienced one hour of lunar daylight followed by one hour of lunar night – definitely no “dark side”.