Waning Gibbous Moon Shines Brightly Tonight: What to Know About December’s Lunar Phase
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As of Tuesday, December 9, the moon is currently in its waning gibbous phase, with 73% illumination, offering ample opportunity for stargazers to observe its surface features.
The moon is steadily progressing toward the new moon phase, following the recent third quarter. According to NASA’s Daily Moon Observation, the illuminated portion will continue to diminish each night until the moon is no longer visible. But tonight, observers are in for a treat.
Observing Tonight’s Moon
Even without specialized equipment, several prominent lunar landmarks are visible. Observers can look for the Mare Tranquillitatis, Tycho Crater, and Oceanus Procellarum with the naked eye.
For those with binoculars, the Gassendi Crater, Clavius Crater, and the Alps Mountains come into view. Serious lunar enthusiasts equipped with a telescope can explore even further, locating the Apollo 15 and 16 landing spots, as well as the Reiner Gamma formation.
Understanding Lunar Phases
The moon’s changing appearance throughout the month is due to its orbit around Earth and the shifting angles of sunlight. The complete lunar cycle, lasting approximately 29.5 days, is defined by eight distinct phases. NASA explains that we always view the same side of the moon, but the amount of illumination changes as it orbits. These phases include:
- New Moon: The moon is positioned between Earth and the sun, rendering the side facing Earth dark and invisible.
- Waxing Crescent: A small sliver of light appears on the right side (in the Northern Hemisphere).
- First Quarter: Half of the moon is illuminated on the right side, resembling a half-moon.
- Waxing Gibbous: More than half of the moon is lit, but it’s not yet full.
- Full Moon: The entire face of the moon is illuminated.
- Waning Gibbous: The moon begins to lose light on the right side (in the Northern Hemisphere).
- Third Quarter (or Last Quarter): Half of the moon is lit on the left side.
- Waning Crescent: A thin sliver of light remains on the left side before disappearing.
When to Expect the Next Full Moon
Mark your calendars: the next full moon is scheduled to occur on January 3. This celestial event continues to captivate observers and serves as a reminder of the dynamic relationship between Earth and its natural satellite.
