See the moon in action! And discover why our view of it changes nightly.

Each night, the Moon  looks a little different. Sometimes it’s almost round, and other times it’s just a sliver. But the Moon doesn’t really change—all that changes is our view.

Unlike the Sun , the Moon doesn’t make any light of its own. Though it looks like it glows, it’s really just reflecting light from the Sun, like a giant bike reflector. In a way, there’s no such thing as moonlight—it’s all reflected sunlight!

Think of the Moon as a giant ball. One half of the ball is always lit by the Sun. As the Moon moves around Earth, different amounts of the sunlit half come into view. Since we can only see the lit-up part, the Moon seems to grow and shrink. We call these changing views the ‘phases’ of the Moon.