The Moon is the only natural satellite of our Earth. Consequently, it is the only planet which has Earth as the center of its orbit. This makes it the only true planet which never retrogrades (the Sun never retrogrades either, but, although astrologers refer to it as a “planet” for convenience, it really isn’t a planet, but rather a star 1).
The Moon goes through a repeating cycle of phases each 29 days as it persues its course through the sky. Like all true planets, the Moon produces no light of its own. We see it “shine” because it reflects the light eminating from the Sun. For this reason, the side of the Moon that faces the Sun is completely bathed in light, while the side that faces away from the Sun is in darkness 2. Depending upon the Moon’s position relative to the Earth and the Sun, we will usually see some portion of both sides. The exceptions are at the New Moon, when we see only the side that is in darkness, and the Full Moon, when we see only the side that is completely lit up.
The cycle is considered to start at the New Moon, when the Moon is aligned with (or Conjunct), the Sun, and no light is reflected to Earth. At the days pass, the Moon waxes in light and we see more and more of the its lighted side. This begins as a small crescent of light along the Moon’s right-hand edge. The crescent grows in thickness until, approximately seven days after the New Moon, we reach the First Quarter Phase. This occurs when the Moon is 90 degrees from (or Square), the Sun, and exactly half of the its surface is lighted (the right half), while the other half remains in darkness.
After the First Quarter Phase, the Moon continues to wax, with more and more of its lighted side turned towards Earth, until the Full Moon Phase is reached roughly fourteen days after the New Moon. Here, the Moon is 180 degrees from (or Opposite), the Sun, and its entire lighted face is turned towards us, with the dark side turned completely away from us.
After the Full Moon Phase, the Moon begins to wane in light. The darkness begins to creep over its surface as a thin crescent along the right-hand edge, just as the light did after the New Moon. The Moon continues to wane until the Last Quarter Phase is reached. Again, exactly half of its surface is lit, while the other half is dark. However, this time it is the left half which is bright, and the right half that’s dark.
The Moon will continue to wane, the lighted crescent along its left-hand side growing thinner and thinner, until it disappears altogether at the next New Moon.
The Moon isn’t the only planet to have phases. Mercury and Venus also go through a complete cycle of phases just like the Moon’s, due to their orbits being closer to the Sun than ours. The planets outside of our orbit (Mars through Pluto), don’t have phase cycles. Since their orbits lie outside of ours,their lighted face is always facing towards us and the Sun.
1 See the article in this series on Why Planets Retrograde
2 If one stares at the Moon very early in the Crescent Phase, one will see a faint, ghostly, deep blue outline of the rest of its disk, which is supposedly in darkness. In truth, what one sees is indeed the dark side being faintly illuminated by “Earthshine.” Just as the Moon lights our nights at times with a ghostly gray radiance which we call Moonshine, and which is in fact the light of the Sun reflected off the Moon’s surface, so the Earth reflects the Sun’s light onto the Moon’s surface – a pale blue light provided by our blue planet to light the nights on the Moon – “Earthshine.”
About the author:
Dwight Ennis has studied astrology for more than 20 years. He was one of the founding members of the South Bay Astrological Society, and was its first President, serving two terms. His primary astrological focus is on the blending of astrological symbolism with Jungian Depth Psychology.