Astrology Glossary · Motion and timing
Moon phase
Where the Moon is in its 29.5-day cycle: new, waxing, full, waning. AIstra mentions the current phase because the Moon's symbolic weight depends on it.
The Moon's phase is its position in the 29.5-day cycle from new to full and back again, defined by the angular distance between Moon and Sun. New Moon is conjunction (0°). First quarter is square (90°). Full Moon is opposition (180°). Last quarter is square again (270°).
Symbolically the cycle is the simplest pattern in astrology. Begin (new), build (waxing), peak (full), reflect (waning), close (balsamic), begin again. People who do not otherwise read horoscopes will still notice the full moon's effect on mood and sleep.
AIstra mentions the current phase often because the Moon's symbolic weight depends on it. A Mars aspect at New Moon reads differently from a Mars aspect at Full Moon — the same friction, but framed by a different point in the cycle. The Moon Calendar page tracks the whole month at once.