The Moon is in a Waning Gibbous phase tonight, meaning approximately 80% of its visible surface is illuminated. This phase occurs after the full moon and before the third quarter, as the illuminated portion gradually decreases. This is a great time for stargazing, as the bright moonlight will still allow for some clear viewing of lunar features.
What You’ll See Tonight
Without any equipment, observers can spot prominent dark areas known as mares – ancient volcanic plains – such as the Mare Imbrium and Mare Tranquillitatis. The Kepler Crater is also visible with the naked eye.
For those with binoculars, the Gassendi and Alphonsus Craters, along with the Mare Nectaris, will become apparent. A telescope will reveal even more detail, including the Apollo 15 landing site, the Schiller Crater, and the rugged Descartes Highlands. These features offer a glimpse into the Moon’s geological history.
Lunar Cycle Explained
The Moon orbits Earth and goes through all its phases in about 29.5 days, which is known as the lunar cycle. The phases we see are caused by how much of the Moon is lit by the Sun from our perspective on Earth. While the same side of the Moon always faces us, the amount of sunlight reflecting off it changes as it moves around our planet.
Here’s a breakdown of the eight main phases:
- New Moon: The Moon is between Earth and the Sun, making its visible side dark.
- Waxing Crescent: A sliver of light appears on the right side (in the Northern Hemisphere).
- First Quarter: Half of the Moon is lit on the right side.
- Waxing Gibbous: More than half is lit, but not fully.
- Full Moon: The entire face of the Moon is illuminated.
- Waning Gibbous: Light begins to fade on the right side (in the Northern Hemisphere).
- Third Quarter (Last Quarter): Half of the Moon is lit, but now on the left side.
- Waning Crescent: A thin sliver remains on the left before becoming dark again.
Looking Ahead
The next full moon will be on February 1st, and the previous one occurred on January 3rd. Tracking these cycles helps understand the Moon’s influence on tides, cultural traditions, and even animal behavior.
The lunar cycle is a continuous reminder of the dynamic relationship between Earth and its natural satellite, shaping both our environment and our understanding of the cosmos.
