Have you noticed that when you look up at the moon, you always see the same features? You can see craters and patches of different colors. With a pair of binoculars or a telescope, you can make out even more detail. But no matter how you look at the moon, you're always seeing the same landscape. What's on the other side of the moon?
Many people use the phrase "the dark side of the moon" to describe something mysterious and unknown. The dark side of the moon is supposed to be the side we never see, the side that faces away from Earth. This side of the moon faces the cold, black expanse of space. What could be on this side of the moon? What are conditions like there? Is it really always dark?
Some astronomers grimace or roll their eyes when they hear someone talk about the dark side of the moon (unless they're also Pink Floyd fans). The popularity of the phrase means that there's ample opportunity for people to jump to the wrong conclusion. Part of the problem is the fact that we always see the same side of the moon. Another part concerns a general misunderstanding regarding the cause of the phases of the moon. But mostly, it's a problem with terminology.
This isn't a hard problem to fix, though. We just need to take a closer look at how the moon moves through space. But first, let's deal with the terminology. There are several terms we can use instead of the dark side of the moon that are much less confusing.
So what exactly is the dark side of the moon, and why is it a misleading phrase? Find out in the next section.