Our social:

Phases of the Moon

See how the phases of Earth's moon work, from the full moon to the new moon and everything in between. The moon is illuminated by light from the sun, what we see from Earth is the sun rays' reflection on the lunar surface. As the moon moves around Earth, the amount of illumination it receives from the sun changes, creating the lunar phases. The moon completes a single lunar cycle in about 29 days.




Image: NASA/Bill Dunford