How to Read the Moon Phases

The Moon is the Earth's only natural satellite. It is considered a satellite in that it regularly orbits another object; that object being our planet. Astronomers theorize that it formed after a Mars sized object collided with our Earth millions of years ago. Our Moon completes one full orbit cycle every 28 days. Many cultures over humanity's history have formed behaviors, rituals, and beliefs all based around the Moon and her ceaseless pattern that she cuts across the sky. We only ever see one side of her face, since her own spin, or rotation, keeps in time with Earth's own orbit around the Sun.

Any person who has looked up into the sky and observed its wonder, has witnessed the Moon in its many phases. These phases occur as the amount of sunlight reflected off of the Moon's surface changes depending on its position in relation to the Earth and the Sun. The most well known phases are known as the New Moon, 1st Quarter Moon, Full Moon, and 3rd Quarter Moon. In between each of these phases are four more known as waxing crescent, waxing gibbous, waning gibbous, and waning crescent. When do these phases occur and what are they?

There are eight phases total in a 28 day orbit cycle. Imagine the Moon's orbit on the face of a clock, with the sun located somewhere to the right of the 3 o'clock position. As the Moon orbits it will move counterclockwise around the clock face.

The beginning phase of the Moon's orbit is the New Moon. A new moon occurs when the moon is located directly in between the Earth and the Sun; at 3 o'clock. Since the sun's light is coming from behind the Moon, it shows us earthlings no reflection; the Moon appears dark. As it moves from a 3 o'clock position, it moves into its waxing crescent phase, which lasts in between the New Moon and the 1st Quarter Moon. The 1st Quarter Moon occurs at what would be 12 o'clock. It appears to be a half moon with the right side of it illuminated.The move from the 12 o'clock position to the 9 o'clock position is known as a waxing gibbous, more than half of the Moon appears illuminated, but not all. Once the Moon reaches the 9 o'clock it has become a Full Moon. The Earth is between the Moon and the Sun.

The first half of the Moon's orbit is known as a Waxing Moon, waxing meaning that it appears to grow in size. The second half of the Moon's orbit is known as a Waning Moon, waning meaning that is appears to shrink in size.

As the Moon moves from the 12 o'clock full position to the 6 o'clock position, it is in the waning gibbous phase. Once it reaches 6 o'clock, the Moon is in its 3rd Quarter Moon phase and the left half of its face appears illuminated. After 6 o'clock, the Moon moves towards the 3 o'clock to finish its circuit. Its move from 6 o'clock to 3 o'clock is known as the waning crescent moon phase. Upon reaching 3 o'clock, the Moon is once again in its New Moon phase, and the 28 day cycle is complete.

Is the Moon only out at night? The answer is no, as the Moon can sometimes be seen in the middle of the afternoon. The time of day that the Moon is visible from the Earth's surface, just like its phases, depends entirely on where it is located during its orbit. If the orbit is cut into eight pieces, the times that the Moon rises and sets are exactly perpendicular to what phase it is on. The main difference between the phases clock face and the rise/set clock face is that the Full Moon position would become midnight, 3rd Quarter would become 6am, New Moon would be noon, and 1st quarter becomes 6pm.

For example, if the Moon were in its Full Moon phase, then it would rise at 6pm, and set at 6am, with its highest point in the sky, its zenith, being midnight. Adversely, if it were a New Moon, then the Moon would rise at 6am, and would set at 6pm with its zenith being at noon.

So, the next time you find yourself looking up at the sky, and you see the Moon in all her glory, you'll know exactly where she is in her cycle, what phase is presently occurring, and what time she will set. Observe our universe and wonder. Good luck!!