How do you describe the lunar cycle?

The Moon CycleThe term "moon cycle" (or "lunar cycle") refers to the moon's continuous orbit around the earth. As the moon orbits the earth, its appearance (the "phase") changes and thus gives us an indication of the moon's progress in the cycle (the "age").

The sun always illuminates exactly one-half of the moon, but we see it at different angles as it rotates around the earth. With the naked eye, we can see only the part of the moon that the sun is illuminating. For instance, a crescent moon is what we call the moon when we see only a small portion of its illuminated surface.

We give the parts of the moon cycle different names, according to how the moon appears to us. In order of appearance:

1. New (also called the Dark Moon) - not visible
2. Waxing Crescent
3. First Quarter - commonly called a "half moon"
4. Waxing Gibbous
5. Full - we can see the entire illuminated portion of the moon
6. Waning Gibbous
7. Third Quarter - another "half moon", but the illuminated part is opposite of the First Quarter
8. Waning Crescent
9. New - back to the beginning

This complete lunar cycle (New Moon to New Moon) is also called a "lunation". During this time the moon will completely circle the earth. That's the scientific definition, but you can take any phase; for instance a so-called "full moon cycle" would be from Full Moon to Full Moon.