Moon ExactlyMoon Exactly
The Eight Moon Phases
One orbit, eight familiar appearances. Each name describes a range in a continuous cycle rather than a shape that changes at midnight.
New Moon
about 0–2%
Waxing Crescent
about 1–49%
First Quarter
about 50%
Waxing Gibbous
about 51–99%
Full Moon
about 99–100%
Waning Gibbous
about 51–99%
Last Quarter
about 50%
Waning Crescent
about 1–49%
A continuous astronomical cycle
The eight names divide a continuously changing phase angle into useful regions. New, quarter, and Full Moons are precise events; crescent and gibbous labels describe intervals between them.
Astronomy remains the foundation
Illumination depends on the angle between the Sun, Moon, and Earth. The lit half of the Moon always faces the Sun; our viewing angle determines how much of that half we see.