WOLFRAM|DEMONSTRATIONS PROJECT

Motion of the Moon: Phases

​
time
If the Moon is closer to the Sun than the Earth, then from the Earth most of it will be dark. If the Earth is closer to the Sun, from the Earth most of the Moon will be bright. The graphic on the left shows the Moon in its orbit around the Earth. The graphic on the right shows the corresponding appearance of the Moon as seen from the Earth; these are called the Moon's phases.
The elements in the diagrams are not drawn to scale.