Whichever stage it is in, the waxing Moon takes the shape of a “D” and the waning Moon of a “C”. Say to yourself that the “D” equals Developing, or increasing, in size, while the “C” equals contracting, or getting smaller.

The Moon actually emits no light of its own. It shines because it reflects light that it receives from the Sun. As the Moon circle the Earth, rays of sunlight strike its surface and illuminate different portions of its face. At that point in its journey, when it lies directly between us and the Sun, the Moon cannot reflect any light back to Earth since the Sun’s rays strike the face of the Moon that is pointing away from us. This renders the Moon invisible from Earth – a point in its cycle known as the Moon’s dark phase.

As the Moon moves out of direct line and begins to sweep around the Earth, the Sun’s rays strike at an angle. The first sign of the New Moon, a slender silver eyelash in the darkened sky, begins to appear. This the start of the Moon’s waxing phase and, from now, as more and more of its face is illuminated by the Sun, the Moon appears to increase in size each night until it reaches half-way around the Earth. At the point, the Moon is at its farthest from the Sun, in direct opposition, so that its whole face is lit up by sunlight. It this position, it is the Full Moon that is seen from the Earth

From here, the Moon begins the second half of its journey around the Earth. As it sweeps around us in its approach to the Sun, it reverses its phases and, with less and less of its face lit up by the Sun, it appears to wane or decrease. It wanes from Full to Last Quarter, to the Crescent and finally to invisibility again, when it aligns itself between the Earth and Sun once more.