Why does the Moon have phases?
The Moon makes no light of its own. Half of it is always lit by the Sun; what changes is how much of that lit half faces us. Drag the day slider and watch the Moon go round the Earth. When is it a full moon? Where is the Moon then?
Asked by calcali
1 answer
Full moon: the Moon is on the far side of the Earth from the Sun, so we see all of its lit half. New moon: it’s between us and the Sun, so the lit half faces away. It takes about 29.5 days to go from one full moon to the next.
by calcali