If you took an evening walk or happened to look out your window eastward last Thursday, you saw what some call the Worm Moon, a term American Indians introduced. While these nomadic people didn’t follow a Julian calendar, they knew the importance of using seasonal moon phases to record passing time.
In certain climate zones, snow had melted enough to reveal visible earthworm casts, indicating returning robins. Thus the March moon became Worm Moon. Northern tribes might call that same orb Full Crow Moon due to cawing of returning crows or Full Crust Moon due to crusts topping snow from spring melts and freezes. Eastern tribes sometimes called it Sap Moon because of rising maple sap. This practice of using seasonal descriptions to name monthly full moons makes each one unique.
It seems calling the moon something specific like Snow Moon (February), Thunder Moon (July), or Long Nights Moon (December) would make humans more aware of passing seasons. Living a migratory life in tipis or other portable housing would also make it easier know moon cycles and their nature connections.
Although I live in a traditional house, moving from city lights to a rural area introduced me to moon phases. Growing up with heavy light clutter, I had no understanding of waning and waxing moons or even about full moons unless it had to do with heading to the beach under a June full moon to capture silvery grunion navigating shoreward to lay eggs. Unfortunately, I hadn’t noticed most calendars indicate moon cycles for the light-clutter impaired.
Driving home from late practices and games, I eventually noticed predictable moon cycles. After several months, I realized the moon waxed or grew into a full moon from the left, or in a D-shape. Shrinking or waning moons disappear from the right in a C-shape. A gibbous moon is one that is convex on both sides. Avid moon gazers synchronize with moon cycles to know whether it is a waning or waxing gibbous moon.
Despite studying moon phases using ping pong balls in a grade school science class, it took seeing that butter-colored satellite go through its nightly paces in rural skies to understand what my teacher tried to show me with ping pong balls.
As I became more attuned to moon phases, I noticed we sometimes have two moons in a month. This happens about every 33 months because moon cycles are about 29 and half days. In recent decades, this second full moon in a month is called a blue moon, hence the saying “once in a blue moon” to mean something that doesn’t happen very often. Even rarer are two blue moons in one year, which must occur on either side of February since it only has 28 days in most years. For those of us who love full moons, we celebrate a blue moon in August of this year. Mark the calendar and plan an extra moonlight picnic or campout.
In the next week or so, the visible moon will shrink to nothing, leaving us with a new or dark moon. Then we can watch it grow into either an April moon if we’re closely tied to the calendar or to a Grass Moon if we prefer to think seasonal change drives the full moon’s name.