Here's why:

* The Moon's light is reflected sunlight. We only see the moon because sunlight reflects off its surface.

* During a new moon, the moon is positioned between the sun and the Earth. This means the sunlit side of the moon is facing away from us, and the side facing Earth is in shadow.

Think of it like this: imagine holding a tennis ball in front of a light bulb. The side of the ball facing the light bulb is lit up, while the side facing you is dark. During a new moon, the moon is like that tennis ball, with the sun as the light bulb, and the Earth as your position.