Sun-Moon Aspects (Synastry)
Definition
A Sun-Moon synastry aspect is a kind of inter-aspect formed by the two great lights across two charts: one person's Sun aspecting the other person's Moon. You check both directions and tally them together. Tighter orbs — usually 6° for the Sun and Moon — are allowed here, because these two carry central weight in both classical and modern reading. When the contact is a conjunction or a close trine, the two natal Suns, or the two natal Moons, often fall in compatible elements as well.
In Tradition
Across modern Western relationship astrology, Sun-Moon cross-aspects are read as among the strongest signs of lasting resonance, set alongside Venus-Mars contacts and contacts to the angles. The Greene–Forrest line frames the pair as solar identity meeting lunar emotional ground: a flowing contact reads as one person's sense of self being naturally held by the other's emotional rhythms. The conjunction reads as identity and feeling fused, flowing aspects as complementary, hard aspects as a friction that can still build something.
In Practice
To work Sun-Moon contacts, you flag every one at the tightest orbs and read each against the birth lights it comes from. You check the host chart's Sun-Moon phase, sign, and house, since a Sun-Moon synastry contact tends to amplify a lunation pattern that was already in that chart. Reciprocal contacts — each person's Sun aspecting the other's Moon — are weighed as a double whammy and read as especially steadying. Sect comes into it too: a Sun in a day chart receiving a partner's Moon behaves differently from a Sun in a night chart in the same setup — sect being simply whether the person was born by day or by night.
Historical Origin
Comparing the lights across two charts is the oldest documented synastry indicator: Ptolemy's Tetrabiblos IV.5 already directs the astrologer to compare two charts' lights and angles to judge friendship and enmity. The methodical reading of Sun-Moon aspects as a relationship's foundation was drawn together in 20th-century Western texts including Liz Greene's Relating (1977) and Robert Hand's Horoscope Symbols (1981).
Etymology
Origin: English. Meaning: Descriptive compound: the two luminaries in cross-chart comparison.
Further Reading
- Liz Greene, Relating: An Astrological Guide to Living with Others on a Small Planet
- Robert Hand, Horoscope Symbols
- Sue Tompkins, Aspects in Astrology