A Calculated Point, Not a Body

Black Moon Lilith is not a physical object but an astrological name for the lunar apogee, the point at which the Moon's orbit lies farthest from the Earth, defined geometrically as the empty second focus of that elliptical orbit, since the Earth itself occupies the first focus. It is a calculated point rather than a body that can be seen. Because the Moon's elliptical orbit is itself slowly rotating, the apogee point does not stay fixed relative to the zodiac but precesses forward through the signs, completing a full circuit in roughly eight years and ten months, the fastest-moving of the major calculated points used in Western astrology.

Ephemerides differ on exactly how to compute it, some giving the smoothed mean position of this precession and others an oscillating true or interpolated position that tracks the Moon's actual, more irregular orbital wobble, so a chart's Lilith placement can shift somewhat depending on which method a given astrologer's software applies. This is distinct from the numbered minor planet 1181 Lilith, an ordinary asteroid discovered in 1927 that happens to share the name but has no orbital connection to the apogee point at all, a coincidence that has caused persistent confusion in popular astrological writing on the subject.