EarthSky // Tonight // Moon Phases by Deborah Byrd
Full moon always comes about two weeks after new moon
, when the moon
is midway around in its orbit of Earth, as measured from one new moon
to the next.
At full moon, we are seeing all of the moon’s day side.
The moon and sun are on a line, with Earth in between. It’s as though Earth is the fulcrum of a seesaw, and the moon and sun are sitting on either end of the seesaw. Thus as the sun sets in the west, the full moon rises.