Waning Crescent

The Waning Crescent is the final phase of the lunar cycle, when only a thin sliver of the lit face remains, shrinking night by night toward the new moon. It appears low in the eastern sky before dawn, rising shortly before the Sun. After it the Moon passes again between Earth and Sun and the cycle begins anew at the new moon. Traditionally the waning crescent is read as a time of rest, surrender, and quiet before renewal, the closing of the round. These are the astronomical facts of the phase together with the meanings traditions attach to it; the thinning crescent is simply the last visible edge of the sunlit hemisphere of the Moon as it approaches the line between Earth and Sun, where its lit face will once more be turned away from us.

The waning crescent is sometimes called the balsamic Moon in modern astrological usage, a term borrowed from the Latin balsamum for a healing resin, framing the phase as a period of distillation and release rather than of decay. In Wiccan and related modern pagan schemes the waning crescent is commonly mapped onto the Crone aspect of a threefold goddess figure, standing opposite the Maiden of the waxing crescent, a symbolic pairing popularised in the twentieth century rather than inherited from older lunar religion. Because the crescent at this stage rises only shortly before the Sun and is quickly lost in its glare, it is also the hardest of all eight phases to observe directly, visible for at most a few minutes low on the eastern horizon before dawn overtakes it.

Sources AstronomyAndrew Fraknoi, David Morrison, and Sidney C. Wolff (OpenStax) with Wicca: A Guide for the Solitary PractitionerScott Cunningham

The waning crescent covers elongation from two hundred and seventy degrees back to three hundred and sixty, which is zero again, between last quarter and the next conjunction. Less than half the disc is lit and the lit limb faces the Sun, so the crescent is seen in the eastern sky before dawn.

The phases are produced by the changing angle between the Sun, the Earth and the Moon, and the quantity that defines them is elongation, the Moon's angular distance from the Sun as seen from the Earth. The complete round from one new moon to the next is the synodic month, about 29.53 days, and it is longer than the sidereal month of about 27.32 days in which the Moon returns to the same place among the stars, because the Earth has moved along its orbit in the meantime and the Moon must travel further to catch up.

The last visible crescent before conjunction is the mirror of the first visible crescent after it, and it is the harder of the two to catch because it is a morning object seen against a brightening sky. Both are limited by the same combination of elongation, altitude and atmospheric clarity.

In the thin crescent phases the dark part of the disc is often faintly visible, lit by sunlight reflected from the Earth. The effect is called earthshine, and it is bright enough to be seen with the naked eye under good conditions, which is why the whole disc can be made out within the arms of a crescent. It is the reason the old moon is described as being held in the new moon's arms in more than one tradition.