About the moon's phases
In both Western astrology and modern astronomy there are 8 traditional phases of the moon. While these divisions are somewhat arbitrary, they are based on a system of four primary phases: New Moon, First Quarter Moon, Full Moon and Last Quarter Moon.
The remaining four phases are transitional phases (either "crescent" or "gibbous" phases). These transitional phases can be thought of as "in between" phases, separating the four primary phases. These transitional phases are the: Waxing Crescent Moon, Waxing Gibbous Moon, Waning Gibbous Moon and Waning Crescent Moon.
The total sequence of moon phases in order is:
- New moon
- Waxing crescent moon (Also called the Evening Crescent)
- First quarter moon
- Waxing gibbous moon
- Full moon
- Waning gibbous moon
- Waning crescent moon
After the 7th and final phase, the New moon arrives again, and the cycle begins anew.
There's no such thing as a "half moon"
You've probably heard the term "half moon" many times. The truth is, this isn't actually one of the names for the moon's phases. The First Quarter and Last Quarter moons are sometimes descriptively called "Half Moons", but the correct term is "Quarter Moon" because they represent the points at 25% and 75% of the full lunar cycle.
Tides and the phases of the moon
The Earth's water is drawn towards the moon at all times. But during some phases of the moon, the effect is more pronounced.
During a Full Moon and a New Moon the Earth's tides are highest (often called a "Spring Tide", although the effect happens at any time of year). During each of the moon's Quarter phases, or "Neap Tides" the pull of the moon is the subtlest and Earth's tides are at their lowest.