correction, The moon has 4 main phases, new, quarter, full, and third quarter moon's. You may think using common sense that what the other answer was correct, but it was not … . Since the sun only faces one side of the moon, only one side of the moon is lit up. That side faces the sun. On earth people see a new moon as a dark moon because the half that is lit faces the sun and away from the earth making a moonless sky. The Quarter moon is when the moon is at a 90 degree angle from the sun.