Science Common Sense

1277 - Why do the phases of the moon change in a regular pattern.

The phases of the moon change because of its relationship with the sun and Earth. The moon orbits around the Earth, and as it moves, different amounts of sunlight reflect off its surface towards us.

Imagine you have a baseball (the moon) and a flashlight (the sun). If you shine the flashlight on the baseball, you see the whole baseball illuminated (full moon). But if you're standing on one side of the baseball and the flashlight shines on the other side, you won't see the light (new moon).

As the moon moves around the Earth, the sunlight reflects off its surface, creating different phases like crescent, quarter, and gibbous. This movement and the changing sunlight create a regular pattern of phases, which repeat every 29.5 days.