The term “Pink Moon” is the traditional name for the full moon appearing in April, part of a system assigning unique names throughout the calendar year. While widely recognized, the moniker often leads to misunderstanding about the moon’s actual color, creating confusion for those expecting a celestial body bathed in a rosy hue.
Addressing the Misconception: The Moon’s True Appearance
The Pink Moon does not appear pink to the naked eye; its color remains the same silvery-white or grayish tone as any other full moon. The moon’s inherent color results from sunlight reflecting off its surface, which is composed of light-gray anorthosite and darker basalt rock.
Any perceived color variation (yellow, orange, or red) is caused by Earth’s atmosphere. When the moon is low on the horizon, its light travels through a greater thickness of air and atmospheric particles. This process, known as Rayleigh scattering, filters out the shorter, bluer wavelengths of light. The longer wavelengths (yellow, orange, and red) reach the viewer’s eye, similar to the colors seen during a sunset. Dust, smoke, or pollution can intensify these warmer tones, but this atmospheric effect is separate from the “Pink Moon” name itself.
The Cultural Origin and Timing of the Pink Moon
The name “Pink Moon” has a historical and cultural origin tied to the natural cycle of spring, rather than any astronomical event. It is one of many full moon names popularized by the Old Farmer’s Almanac, drawing from Native American, Colonial American, and European traditions. The name is attributed to the widespread blooming of a particular wildflower native to eastern North America.
This plant is Phlox subulata, commonly known as moss pink or creeping phlox. The species is one of the earliest and most prevalent flowers to produce a blanket of dusty pink blooms in early springtime. The April full moon was named to mark the time of year when this plant began to flourish. This naming convention served as a natural calendar for early communities, signifying the return of warmer weather and renewal.
The Pink Moon occurs annually as the full moon of April, though its precise date shifts each year because the lunar cycle averages about 29.5 days. The timing was also historically linked to religious observances; it is often known as the Paschal Moon in the Christian calendar because it helps determine the date of Easter. Other names used by various Native American tribes for the April moon reflect seasonal changes and activities of early spring, including the Sprouting Grass Moon, the Egg Moon, and the Fish Moon.