Synastry asks how two charts touch. A composite chart asks what kind of third thing those two charts make when you midpoint every pair of planets and build a new nativity.
They are not two brandings of the same diagram. A Venus–Saturn square in synastry is “your Venus meets their Saturn.” A composite Saturn on the composite Sun is “the relationship itself talks like a Saturn-Sun person.” Different grammar. Different question.
Davison is a third method — a time-and-place midpoint, not a planetary midpoint. See Davison. How to sit with any of these without a verdict: how to read a relationship reading.
Synastry: You and I
Overlay two natal charts. Draw aspects from my planets to yours. Optionally drop my planets into your houses (house overlays).
Strengths:
- Keeps two subjects. Consent, history, and two nervous systems stay visible.
- Good for “what happens when we are in a room” — Moon contacts, Venus–Mars, Saturn contacts.
- Survives a missing birth time better than composites (houses wobble; planet-to-planet aspects often survive). See synastry without birth time.
Failure mode: a red-line square treated as a breakup appointment.
Composite: The We
For each planet, take the shorter-arc midpoint between the two natal positions. Put those midpoints on a wheel. The composite Ascendant needs two birth times and a chosen location method (often the meeting place or the current city — schools argue).
The composite Sun is a thesis of the relationship’s visible job. Composite Moon is the shared emotional weather. Composite Saturn is the cost of keeping the we intact.
Strengths:
- Names the project (a band, a marriage, a company) as if it had a chart.
- Useful when the question is “what is this thing we built?” not “do I like you.”
Failure modes:
- Treating the composite as more real than the two people.
- Building a composite on noon placeholders and then reading houses as fate.
- Mixing a synastry aspect into a composite sentence in the same breath.
Which to Pull First
| Question | Start with |
|---|---|
| How do we affect each other? | Synastry |
| What is the relationship’s job / public face? | Composite |
| We just met and one time is unknown | Synastry, planets only |
| We are deciding whether to keep a shared project | Both, labeled |
| I want a yes/no on “meant to be” | Neither. See questions to ask |
If the two methods disagree — easy synastry, heavy composite Saturn — you may have a warm pair inside a demanding project. That is a readable tension. It is not a vote you must resolve by deleting a method.
The Whisper’s compatibility layer compares charts; it does not replace a hand-drawn composite consult. Ask which engine a reading used.
Frequently Asked Questions
Is a composite more “accurate” than synastry? Different object. Accuracy is the wrong word. Fit-to-question is the right one.
Do I need both birth times? For composite houses, yes. For synastry planet-to-planet aspects, often no.
What about Davison? A real-time midpoint chart, not a planetary-midpoint chart. Do not use the words interchangeably.
Can a composite predict a breakup? It can describe a tone. People still leave, stay, and renegotiate for non-astrological reasons.
Where next? Method: synastry guide. The other midpoint: Davison. Reading hygiene: how to read a relationship reading.
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