So why does the moon have phases? Depending on the alignment of the moon, Earth, and sun, we’re able to see different amounts of the surface of the moon called phases. The reason why we can see these parts of the moon is because we’re looking at the reflected sunlight on the moon’s surface. A new moon happens when the moon is directly between the Earth and the sun. The surface getting all of the sun’s light is the face of the moon on the opposite side from Earth, so it appears as nothing in the sky to us. On the other hand, a full moon happens when the Earth is directly between the moon and the sun. We can see the full surface of the moon because all of the sunlight rays are directed at the side closest to Earth. One of the really interesting things about the part of the moon we see is that the way the moon revolves around the Earth makes it so that we only ever see the same side of the moon. No one looking at the moon from Earth will ever be able to see the other side of the moon.