Where is the dark side of the Moon?

The other day I gave my students an astronomy misconception quiz.  One of the questions asked was "where is the dark side of the Moon?"  The common misconception that many people have is that the dark side of the Moon is the side of the Moon that faces away from the Earth.  People tend to recognize that we only see one side of the Moon.  In more scientific terms, due to gravitational and frictional forces between the Earth and the Moon, the Moon is tidally locked with the Earth and the same side always faces us.  This is relatively common in our Solar System.  There are many moons tidally locked with their planet in some way. For some reason the knowledge that we always see the same side of the Moon leads many us of us to conclude that if we can't see the other side it must be dark.  This, of course, is not true.

If this isn't true, then where is the dark side of the Moon?  The answer is everywhere.  Every position on the Moon experiences periods of sunlight (day) and periods of darkness (night).  This is no different than the Earth.  Right now it's night for half of the Earth and day for the other half.  It's just matter of where your located.  Take a look at the diagram below, remembering that the same side of the Moon always faces the Earth.

The original uploader was Minesweeper at English Wikipedia. [CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/)]

The Sun is located to the left on this image.  Notice that half of the Earth is lit and half of the Moon is lit for each Moon position.  Start with the Full Moon on the right.  The half of the Moon that is lit is facing the Earth.  So we the Moon fully lit as you can see in the image below.  

Gregory H. Revera [CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)]

Now look at the New Moon in the first picture.  The side of the Moon that is lit is facing away from the Earth and the dark/night side is facing Earth.  So we see the following.

Sardaka [CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)]

Technically this is a picture of a crescent Moon but it's very close to a New Moon.  During the New Moon phase, no part of the Moon's surface that we see on Earth is illuminated.  

To conclude, there is a dark side of the Moon, but it's not the side of the Moon facing away from us.  The dark side of the Moon changes as the Moon orbits around the Earth.  My daughter hasn't asked me this question, and it's not the type of question I expect a child/student to ask unless they've already been confronted with the misconception.  If you or your child are confronted with the misconception that the dark side of the Moon is the side facing away from Earth, now you have the knowledge to combat and destroy this misconception.