This guide simplifies the basic science behind major and minor moon phases and cycles. It also provides some interesting facts and tips on how to identify these different aspects of our lunar partner.
Our modern culture largely ignores our closest celestial partner, but we cannot deny this lunar satellite’s impact on our planet. Its gravitational pull affects the tides of the oceans and lakes to a lesser extent. Plus, it provides indirect light at night and several methods for measuring time.
“The moon, by her comparative proximity, and the constantly varying appearances produced by her several phases, has always occupied a considerable share of the attention of the inhabitants of the earth.” — Jules Verne
Simplifying Moon Phases
The most obvious question is, what causes these different phases or cycles? A phase is how we recognize the day-to-day change of our lunar partner. A moon cycle is a way we measure the moon’s orbit around the Earth. It takes the Moon 29.5 days to orbit the Earth. See, that was easy.
We can see our lunar partner because it reflects sunlight. Sometimes, we only see a partial reflection because the Earth gets in the way. There are eight major moon phases, which are the easiest to spot. All the transitional phases in between these major phases are considered minor.
Our lunar partners, the Sun and the Earth, are in an intricate cosmic dance that gives us the changing phases of our lunar satellite. We know the full moon affects the tides of the oceans. It also stabilizes the Earth’s magnetic field, stabilizing its wobble, which stabilizes our seasons. The major and minor moon phases and cycles have a profound effect on the planet’s life.
There are 13 complete moon cycles each year. Each cycle is equivalent to a month of lunar time, but how you measure them will give you slightly different days in each cycle.
“We are full of rhythms . . . our pulse, our gestures, our digestive tracts, the lunar and seasonal cycles.” — Yehudi Menuhin
When we keep track of the changing phases of the moon, it puts us in touch with the daily routine of our ancestors, who planted, harvested, and hunted using the benchmarks of the moon. Learning the major and minor moon phases will give you a new perspective on the Earth and our lunar partner.
The full moon is a benchmark timepiece in many cultures, from ancient Babylonia and Egypt to North American Indians. However, the moon’s sacredness is lost to modern culture because it does not fit into Western theology’s dominant cosmology.
Many ancient civilizations used the moon to create a 13-month annual calendar instead of the stars or zodiac signs.
Measuring All Types of Moon Phases
There are several ways to measure the different phases of our lunar partner. Here are the most used methods for a monthly circuit. These methods for calculating these cycles are not for dummies. It’s easy to get lost in intricate math, geometry, and astronomy. Here are the primary methods and their results if you are curious.
Draconic = 27.212220815 days
The Draconic, or nodical, is the time it takes for the moon to pass through the same node or intersection in its orbit. It takes 18.6 years for the plane of the moon’s orbit to complete a full circle, so the nodes move backward over the ecliptic with the same period.
Tropical = 27.321582252 days
The Tropical method measures the moon’s procession in the sky to the Vernal Equinox. It takes the moon “less time” to return to an ecliptic longitude of zero than to the same point amidst the fixed stars, so it takes slightly less than 28 days.
Sidereal = 27.321661554 day
A Sidereal month is measured by counting the days from a fixed reference. Our lunar satellite orbits the Earth roughly every twenty-eight days. It depends on how and what you measure. For instance, if you count the cycle on when it returns to the same point in the celestial landscape of stars, they call this a Sidereal Month.
Many ancient cultures of the Middle East, India, and China used the Sidereal method, fixing their lunar satellite with specific stars or constellations. This way, they knew they had completed the moon cycles, which would take between 27 and 28 days. Still, a written calendar can work regardless of the weather.
Anomalistic = 27.554549886 days
Most satellites have an ellipse orbit and not a perfect circle; it’s the same for our lunar partner. And this orbit’s orientation (as well as the shape) is not fixed. Some cultures discovered the farthest points of this precession, which would take about nine years. It moves ahead on this route with each cycle. This longer period is called the anomalistic month.
Synodic = 29.530588861 days
The phases of the moon depend on its relation to the Sun. Since the Earth orbits the Sun, the moon takes extra time to catch up when completing a Sidereal month; this longer period is called the synodic month.
The bottom line on the Different Kinds of Moon Phases
Since the moon is continually changing, if you want to get down to it, there are 28 phases. The problem is the change from one to the next is hard to see with the naked eye. Ancient cultures measured this precision at the most prominent points. They didn’t have telescopes. So, this restricted what they could see. It’s the main reason for creating a lunar calendar.
The bottom line is that there are roughly 28 days in one of the moon cycles. To keep track of the cycle, you must decide which phases to use to begin counting. The easier it is to see, the better. Keeping a running tally also helps since cloud cover could obscure your ability to see each phase. It’s one reason ancient cultures mapped out the entire year. Once you can establish the starting point of the cycle, then it doesn’t matter if you can’t see it.
The full moon and the new moon are the most straightforward to recognize. When the moon is complete, you see it as a round orb in the sky. When the moon is new, it is invisible to the naked eye. We’re not sure why they call it a new moon when you can’t see it.
When the full moon gets smaller, this is waning, so it takes 14 days for our lunar partner to disappear; they call this point the new moon. Some people consider the full moon part of the waning cycle, but some see it as the waxing stage resolution.
Waxing means to increase, and there are approximately 14 days in the waxing cycle. When it is partially visible, waxing, or waning, it is called gibbous or less than a full circle.
The adjective gibbous is from the Latin noun gibbous, which means hump or humpbacked. In the 14th Century, the English described something less than a full circle. No one is sure how it got from meaning hump or bulging to less than half a circle is a mystery. I guess they just liked the sound of the word.
Okay, so here is something else to consider about waxing and waning. In the Southern Hemisphere, a waxing moon goes from left to right. It is the opposite in the Northern Hemisphere; it increases from right to left. There is no need to worry; there won’t be a test on this.
Organizing Major and Minor Moon Phases
We can divide these phases into several ways, starting with the simplest. The first way is to count one complete cycle, counting 28 days from the full moon. This method gives you one entire circuit of the moon. The hardest part is determining when it is full.
Next, count 14 days from the full moon. It will take you through the two simple divisions: waxing and waxing. Again, waxing means to increase. There are approximately 14 days in the waxing cycle. When it is partially visible, either waxing or waning, they call this gibbous or less than a full circle. The first is when the moon gets more prominent, and the second is when it gets smaller.
The next grouping divides the lunar progression into four primary cycles (1), each with seven days.
1) Waxing Crescent
2) Waxing Gibbous
3) Waning Gibbous
4) Waning Crescent
The next popular is to divide each cycle by quarters; this gives us eight partitions.
The Eight Major Moon Phases
1) Start with the new moon on day 1
2) Waxing crescents from 3 to 5 days into the phase
3) The first quarter is seven days into the cycle
4) Waxing gibbous at about ten days
5) Full moon at approximately 14 or 15 days into the cycle
6) Waning gibbous around day 17
7) The last quarter is about day 21
8) Waning crescents from 23 to 25 days into the cycle
We prefer the set that includes two additional vantage points: a young phase, about 30 hours after the new moon, and a stage called old, about 30 hours before the lunar disappears into the new phase. That gives us ten steps. Is that too many?
If you want to go crazy, each day of the 28-day cycle is a separate phase. We think that’s a bit too many. Or an easier way to count days starting with any of the eight major moon phases like the new or full moon. Easier yet, download or purchase a lunar calendar.
How Can You Use This Information?
- Use this formation to get the most out of stargazing. The best time is close to the new moon.
- Keep track of the 13-month moon calendar.
- Create a ritual to honor your ancestors on specific lunar holidays.
“Another hundred years may pass before we understand the true significance of Apollo. Lunar exploration was not the equivalent of an American pyramid, some idle monument to technology, but more of a Rosetta stone, a key to unlocking dreams as yet undreamed.” — Gene Cernan
Learning all types of moon phases puts us in touch with our ancestors and helps us appreciate the sacrifices of the generations before us. It teaches us about continuity. When you gaze up at the lunar satellite, you see the surface that all of your ancestors saw back at the beginning of humankind.
“Time is always fleeting and the lunar phases represent that visually for me. What people take away from that and how they apply it within their own lives, that’s entirely up to them.” — Jacob Bannon
The major and minor moon phases are ancient culture’s anchors grounded in nature. A philosophy grounded in nature is at odds with commercialism and Western theology. Commericialsm teaches us to ignore the importance of caring for the Earth and the environment for monetary profit.
References
(1) Lunar Phase, Wikipedia