Synastry · September 4, 2026 · 9 min read
How Synastry Really Works (720 Pairs, Explained)
Compatibility is not "air gets along with fire." Real synastry compares ten planetary contacts between two charts. Here is the machinery, made readable.
01
Beyond sun-sign checkboxes
Sun-sign compatibility compresses twelve personalities into four elements and calls it a match. Real synastry compares the two charts point by point: Venus to Mars for chemistry, Moon to Moon for emotional rhythm, Mercury to Mercury for how you argue. Two Leos can be incompatible; a Leo and a Pisces can be seamless. The degrees decide, not the labels.
02
The five contacts that matter most
Venus–Mars: attraction and how desire moves between you. Moon–Sun: whether your instincts and identity reinforce each other. Moon–Moon: the private rhythm of cohabitation. Mercury–Mercury: how conflict gets spoken. Saturn contacts: where the relationship builds structure — or strain. Every one of these is an angular distance, and every one is computable.
03
Why 720 pairs
Twelve signs paired with twelve gives 144 sun-pairings; extend to the full contact matrix between two charts and the pair space Alfalaki computes is 720 distinct synastry profiles, each with its own reading. That is the difference between a quiz and an instrument.
