As the nights grow longer in early December, sky-watchers across the globe have been treated to a mesmerizing lunar display. The moon, in its eternal dance around our planet, is now moving through the Waning Gibbous phase—an often overlooked, yet strikingly beautiful, segment of its monthly cycle. According to NASA's Daily Moon Observation and reports from EarthSky, the moon's visibility is gradually shrinking each night as we approach the New Moon, but for now, there’s still plenty to spot in the evening sky.
On December 7, 2025, the moon was classified as Waning Gibbous, with a dazzling 90% of its surface illuminated. By the following evening, December 8, that illumination had dipped slightly to about 84–85%, but the moon remained large and bright, its presence impossible to miss for anyone glancing upward after sunset. This phase, which follows the Full Moon, marks a period when the moon’s light is slowly receding—each night, it rises a bit later and its glowing face becomes a little less full, inching toward the Last Quarter and, eventually, the New Moon.
“The moon is shrinking in visibility each night as we inch closer towards the New Moon,” NASA notes, reminding observers that soon, the familiar lunar glow will vanish entirely from the night sky for a few days. But until then, the Waning Gibbous moon offers a unique opportunity for both casual stargazers and dedicated astronomers to enjoy its features.
What can you see during this phase? Quite a lot, as it turns out. Even with the naked eye, the Serenitatis and Tranquillitatis mares—vast, dark plains formed by ancient volcanic activity—are clearly visible. For those with binoculars, the experience becomes even richer: the Gassendi Crater, Endymion Crater, and the rugged Apennine Mountains come into sharp relief. And if you’re lucky enough to have a telescope, December’s Waning Gibbous moon reveals even more treasures, including the Apollo 12 landing site, the dramatic Rupes Altai escarpment, and the distinct Linne Crater. It’s a reminder that the moon’s surface, so often seen as a simple glowing orb, is actually a landscape of remarkable diversity and history.
The lunar cycle itself is a marvel of celestial mechanics. Lasting about 29.5 days, this cycle is divided into eight distinct phases, each with its own character and significance. As NASA explains, “The lunar cycle... is made up of the Moon’s phases, which describe how the Moon looks from Earth as it travels around us. We view the same side of the Moon at all times, but the sunlight hitting its surface shifts as it moves through its orbit.” That shifting illumination is what causes the familiar changes—from the darkness of the New Moon, through crescents and quarters, to the brilliance of the Full Moon, and back again.
Let’s break down those phases for the curious. The cycle begins with the New Moon, when the moon is positioned directly between Earth and the sun, rendering its illuminated side invisible from our vantage point. Next comes the Waxing Crescent, with a sliver of light appearing on the right side (in the Northern Hemisphere). The First Quarter follows, where half the moon’s face is lit. As the moon continues to wax, it enters the Waxing Gibbous phase, with more than half illuminated but not yet full. The Full Moon is the moment when the entire face shines brightly. Afterward, the Waning Gibbous phase begins—the current state of the moon—where illumination starts to decrease. This leads to the Third Quarter (or Last Quarter), with the left half lit, and finally the Waning Crescent, a thin sliver of light before the cycle restarts.
This monthly rhythm isn’t just a treat for astronomers. Across cultures and throughout history, the moon’s phases have provided a natural calendar, marking the passage of time and guiding everything from agricultural practices to religious rituals. As noted by EarthSky, “The phases of the moon provide a reference for calendars and cultural practices and indicate the moon’s position in the night sky.” In many societies, the first sighting of a crescent moon signals the start of a new month or a significant festival. Even today, the lunar calendar is used alongside the solar calendar in various parts of the world.
But why does the moon change shape at all? It’s a question that’s fascinated people for millennia. The answer lies in the interplay between the moon’s orbit around Earth and the sunlight that strikes its surface. As the moon moves through its orbit, the angle between the sun, moon, and Earth changes, altering how much of the illuminated half we can see. This simple geometry gives rise to the cycle of phases that repeats every 29.5 days, offering a reliable celestial clock that has guided humanity for ages.
For those wondering when the next big lunar event will occur, mark your calendars. The next Full Moon—known as the Wolf Moon—will rise on January 3, 2026. This event not only marks the first Full Moon of the new year but also signals the beginning of another lunar cycle. According to NASA and EarthSky, the Wolf Moon follows December’s so-called Cold Moon, and while some years December features a dramatic supermoon, 2025 will not. Still, the moon’s steady progression through its phases continues to captivate and inspire.
It’s easy to overlook the Waning Gibbous phase, sandwiched as it is between the drama of the Full Moon and the anticipation of the New Moon. Yet, it offers its own subtle beauty and opportunities for discovery. Each night, as the moon’s light fades a little more, the details of its surface become sharper and the shadows longer, revealing features that are sometimes washed out when the moon is full.
“Each year has a unique cycle of the Moon’s phases, which adds to the beauty of the night sky through its own distinct rhythm,” EarthSky reflects. Whether you’re gazing up with awe, tracking lunar phases for cultural reasons, or simply enjoying the quiet company of the moon on a winter night, the lunar cycle is a gentle reminder of the universe’s enduring patterns.
As December’s moonlight wanes, take a moment to look up and appreciate the moon’s journey. Its phases connect us not only to the cosmos but also to centuries of human wonder, tradition, and scientific curiosity.
