The figure of Lilith represents one aspect of the Great Goddess. In ancient Babylon, she was worshipped as Lilitu, Ischtar or Lamaschtu. Jewish mythology already puts her into darker realms - an evil Demon of the night, a fitting mate for Satan, lying in wait for men, and killing children.
The Astronomical Lilith
The Moon travels along an elliptical path around the Earth. An ellipse has two focal points, and the other focal point, not occupied by the Earth has been called the Dark Moon, the Black Moon or Lilith. This is a slightly simplified definition, since, actually, the Moon and the Earth both move around their common centre of gravity, and the path of the Moon is not a neat ellipse, but a rather wobbly affair. One must distinguish between the mean orbit of the Moon, which is a slowly elongating ellipse, and the actual orbit, which vaccilates around the mean path, due to interference of various kinds. Just as there a "mean" and a "true" Lunar Node, so there is a "mean" and a "true" ellipse and a "mean" and a "true" Lilith. I write "true" in inverted commas, because the Moon's Node is only "true" about twice per month, when the Moon is actually on it, for the rest of the time, it is as "untrue" as the mean Node. In fact, when working with a point so close to the Earth, one should also take the great parallax into consideration, i.e. consider, from which point on the Earth one is actually looking at a point in the heavens. Astrology observes the planets geocentrically, as if from the Earth's centre, and not topocentrically, from the actual place of the observer.
The Dark Moon has also been defined as the apogee of the Moon's orbit, or that point in the orbit farthest from the Earth. Both these points, the apogee and the second focal point, lie on the long axis of the orbital ellipse, the line of apsides. Seen from the Earth, they lie in the same direction, and therefore occupy the same place in the zodiac. The second focal point lies at a distance only about 36´000 km from the Earth, the apogee at about 400´000 km. Apart from this, both definitions can be regarded as being equivalent. Because the orbit of the Moon continually shifts forward in space, the Dark Moon moves along the zodiac at about 40° per year. A complete revolution takes 8 years and 10 months.
Lilith in the Chart
The glyph used for Lilith is a black Moon, as opposed to that used for the real Moon. Lilith is included in the chart drawing Type 2.AC, some other drawing types, such as 2.AT show Lilith in the table of planetary positions.
"During my years of astrological practice, I have come to use the Dark Moon in all my chart analyses, as a complement to interpretating the Moon. It would never occur to me to neglect this influence. The Dark Moon describes our relationship to the absolute, to sacrifice as such, and shows how we let go. In transit, the Dark Moon indicates some form of castration or frustration, frequently in the areas of desire, a powerlessness of the psyche, or a general inhibition. On the other hand, it shows where we question ourselves, our lives, our jobs, and our beliefs. I feel this is important, since it gives us the opportunity to "let go" of something. The Dark Moon shows where we can let the Whole flow into our selves, without putting an "I" in the way, without putting up a wall in the form of ego. At the same time, it doesn't indicate passivity - on the contrary - it symbolizes the firm will to be open and trusting, to let the Greater World flow through one, relying entirely on the great laws of the universe, on that which we name God. To prepare us for this opening, the Dark Moon creates a necessary void."
(Joëlle de Gravelaine in "Lilith und das Loslassen", Astrologie Heute Nr. 23)