A planetary dance

Musings on our Moon

Lviatour, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia

Last month I presented an eight part wheel of the year that makes the most intuitive sense to me - that feels like a better fit with my experiences of seasonal cycles than the twelve-month calendar. Alongside that annual cycle, I am finding myself increasingly attuned to the phases of our Moon.

(I cannot bear to “it”-ify our Moon, and so I will use feminine pronouns. I could attempt to rationalize this based on tradition or literature, but it is more of a feeling - that I have felt much more aware of the Moon since re-embodying a feminine aspect of my nature. And I am coming to understand that not everything requires an explanation.)

As best as scientists can hypothesize, our Moon was formed when a Mars-sized planet collided with Earth early in the formation of our solar system. Like Earth, she has a core of solid and liquid iron. Her surface is mostly anorthosite, a light volcanic rock believed to have crystallized and separated slowly when the Moon was covered in an ocean of molten lava, soon after her cataclysmic birth, like ice forming on a lake. She bears the visible scars of billions of years of asteroid impacts, lacking the tectonic and weathering processes and liquid oceans that disguise and dissolve evidence of collisions on Earth.

Looking down from above the Earth’s north pole, the Moon orbits counterclockwise - the same motion as Earth’s rotation, Earth’s orbit around the Sun, and the Sun’s rotation: an ancient conservation of angular momentum from the rotating and coalescing disk of gas and dust that gave rise to our solar system. Relative to the Sun, she completes her orbital cycle in 29.5 days, but as her gravitational dance is with both Earth and Sun it varies a little. There are 12.4 lunar cycles in one year. These imperfect multiples ensure that there are no meta-cycles, no repeating patterns. Our twelve “moonths” are an approximation, but she keeps her own rhythm, distinct from the cycles of Sun and seasons.

The Moon is our companion in “inner space”, the only planetary sphere among billions close enough that we can observe her roundness and her surface details with our eyes. Light travels instantaneously on Earth and so slowly at a galactic scale that it takes years to reach the nearest stars, but it bounces back and forth between Earth and Moon in about the time it takes to toss a baseball across the infield. Moonlight is reflected sunlight, and on crescent Moon evenings we can even see “earthshine” faintly illuminating the dark side: twice-reflected sunlight bouncing from the daylight side of Earth to the Moon and back.

Earth, as viewed from the Moon. Bill Anders (Apollo 8 astronaut), public domain, via Wikimedia Commons

The Moon is 390 times smaller than the Sun, measured from side to side, but by coincidence or divine reason is also 390 times closer to us, so that Moon and Sun appear exactly the same size in the sky, and the Moon is just large enough in the closer part of her orbit to block out the Sun over a small area, creating a rare and fleeting solar eclipse.

Our Moon tugs gently on the waters of our oceans, creating the tides. Without a Moon we would have no tidepools, no tideflats, no intertidal and estuarine ecosystems. Without moonlight our nights would be uniformly dark; many nocturnal creatures are uniquely adapted to her soft illumination. And a number of species have adapted to track the Moon’s timings. Corals of the Great Barrier Reef spawn in synchrony a few days after a Full Moon, and some wide-ranging seabirds reunite with their mates on Full Moon nights after weeks or months apart.

The most profound effect of our Moon, however, is more subtle. Her gravitational tug stabilizes Earth’s axial tilt, in the same way that swinging with a dance partner stabilizes our bodies in motion. Without a large planetary companion to offer stability, Earth’s axis would wobble like a spinning top, creating vast swings in climate that would make evolution of complex life and biodiversity much more difficult.

If we look skyward at the same time of day in the northern hemisphere, the Moon moves to the left by about the width of an outstretched hand each day, rising and setting later than the day before. She is visible in the evenings in the first half of her cyle and in the mornings in the second half, and when at least 3-4 days away from New Moon she is also visible in daylight, trailing the Sun across the sky when waxing and leading the Sun when waning. She follows the same path as the Sun through the constellations of the zodiac, moving through all twelve in each cycle. The Full Moon is always opposite the Sun - low in the midnight sky in summer when the Sun is high and high overhead in winter when the Sun is low. The four phases of the Moon are described in astronomy-speak as waxing crescent (from New Moon to first quarter), waxing gibbous (from first quarter to Full Moon), waning gibbous (from Full Moon to last quarter), and waning crescent (from last quarter to the New Moon beginning of the next cycle).

My re-embodiment experience last December completed around sunset on the day of a first quarter Moon, which to me symbolized masculine and feminine, light and darkness in balance and wholeness. So I have come to see the first quarter as a sort of birthday, by whose reckoning I am now nine moons old.

I have also adopted a ritual of finding the Moon each day, whenever clouds and schedules allow. With a clear view of the western horizon, she is visible just a day after New Moon as the slimmest crescent sinking into the twilight glow, and with a clear view of the eastern horizon she rises as a thin line in the light of dawn on the last day of her cycle. I call these “secret moons” - visible only if we know where and when to look. As somewhat of a night owl who is seldom awake before sunrise, I can lose track of the Moon during the second half of her cycle, though I still notice her high overhead or sinking in the western sky in daylight.

Our libraries are awash in folklore and traditions of gardening and farming by the Moon, and scheduling particular activities for particular Moon phases. But in keeping with the overall Dendroica Project theme of developing a personal ecological spirituality, a personal relationship with the world we inhabit, I am less interested in what books have to say and more interested in my own perceptions. And so I would ask of my readers: what does the Moon mean to you? What do you feel when gazing moonward? How do her rhythms and cycles resonate within your own experience?

The Moon is 18 days old today, counting from the last New Moon, and in the waning gibbous phase. She is high in the sky in the wee hours of the morning, sets just before noon, and rises again just after 9pm in the northeast. If clouds permit, see if you can find her, and offer her gratitude for being our orbital dance partner, holding Earth steady in a swing that has lasted for billions of years and will continue for billions more.

Happy Equinox everyone!