Understanding the Waxing and Waning moon

Here's a gorgeous model demonstrating the way that visually, from our position in the Northern Hemisphere, both light and darkness cover the moon's face starting from the right edge and proceeding to the left, as she moves through her pattern of "faces" (phases). 

In the southern Hemisphere, the orientation reverses and these changes move across the moon's face from left to right.

The phases ("faces") tell us when the moon is waxing (gaining light) or waning (losing light). To employ the system of Moon-Timing to synchronize your cycle, it helps immensely to actually LOOK at the moon regularly and begin to familiarize yourself with this pattern (of course, The MoonTimer calendar is designed to help with this process of pattern recognition)! 

The procession of the moon through all her phases is called a Lunation, and is an example of periodicity: a pattern of change that is constant. This same pattern repeats continually in the sky. 

The Full Moon (the 'wedding moon' - because in the traditional model, it is the moon for ovulation) and the New Moon (the invisible 'no moon' - the moon for menstruation) are separated by an interval of two weeks, and our own bodies can easily resonate to this same pattern of fullness (Full Moon) and emptiness (New Moon). It is the light of the full moon that stimulates ovulation through its effect on the pineal gland.  

Thanks to: https://watchers.news for the models and text below. 

 These 4K visualizations show the Moon's phases and libration at hourly intervals throughout 2017, as viewed from both hemispheres. In addition, they show the Moon's orbit position, sub-Earth and subsolar points, distance from the Earth at true scale, and labels of craters near the terminator. Each frame represents one hour.


Northern Hemisphere


Southern Hemisphere

 The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 24 seconds, as it is in this animation, our changing view of the Moon makes it look like it's wobbling. This wobble is called libration. The word comes from the Latin for "balance scale" (as does the name of the zodiac constellation Libra) and refers to the way such a scale tips up and down on alternating sides. The sub-Earth point gives the amount of libration in longitude and latitude. The sub-Earth point is also the apparent center of the Moon's disk and the location on the Moon where the Earth is directly overhead. The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point. The roll angle is given by the position angle of the axis, which is the angle of the Moon's north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by about 14%.

 The most noticed monthly variation in the Moon's appearance is the cycle of phases, caused by the changing angle of the Sun as the Moon orbits the Earth. The cycle begins with the waxing (growing) crescent Moon visible in the west just after sunset. By the first quarter, the Moon is high in the sky at sunset and sets around midnight. The full Moon rises at sunset and is high in the sky at midnight. The third quarter Moon is often surprisingly conspicuous in the daylit western sky long after sunrise.

 Video credit: NASA's Goddard Space Flight Center/David Ladd