Here's why:
* The moon doesn't produce its own light. It's a large, rocky body in space.
* The sun is the source of light. The sun emits a vast amount of light and energy.
* The moon's surface reflects sunlight. When sunlight hits the moon's surface, some of it is absorbed, but some of it bounces back, or reflects, towards Earth.
This reflected sunlight is what we see as moonlight. The phases of the moon (new moon, crescent, full moon, etc.) are caused by the changing angles at which we see the sunlit portion of the moon as it orbits Earth.
