Moon Phase

Real World Example

Imagine trying to view a friend's face while they're turning slowly around in a room with a spotlight shining from one side. Just like how your view of your friend changes depending on how much of their face is illuminated by the spotlight, the phases of the moon change based on how sunlight hits the moon and how much of that lit portion is visible from Earth. Just as your friend's face goes from fully illuminated to partially visible depending on their position in relation to the light, the moon appears to change shape as it orbits around Earth, with varying amounts of its sunlit side becoming visible to us.