Compare two charts. See how you fit.
Synastry shows the aspect dialogue between any two people's natal charts — what fits, what challenges, where the relationship lives.
What is Synastry?
Synastry is the chart-comparison technique astrologers use to read a relationship. Two natal charts are placed in dialogue, and the aspects formed between their planets reveal where two people resonate, where they challenge each other, and where they meet without trying.
In archetypal terms — the lens Carl Jung gave us — synastry is two psyches in conversation. Your Sun meets their Moon. Your Mars meets their Venus. Each crossing carries a recognizable pattern: an attraction, a friction, a steadying influence. Reading those patterns is reading the relationship as it actually is.
Aurathea is a mirror, not a predictor. Synastry here is not a compatibility score that says yes or no. It is a careful reading of how two charts speak to each other, offered so you can see what is already there and choose your own path.
How Aurathea reads synastry
Three layers, each available at a different tier. You can begin with the base layer for free.
Aspect dialogue (Free)
Up to 10 aspects between the two charts — conjunctions, oppositions, trines, squares, sextiles. The base reading shows where the two psyches meet directly.
House overlay (Studio)
Each person's planets falling into the other's houses — the lived-life context in which the aspects play out. Whose Mars lands in whose 7th? That is where the relationship lives.
Element + modality blend (Astrologer)
The composite picture: which elements (fire, earth, air, water) and modalities (cardinal, fixed, mutable) the two charts share or complement. Includes composite-chart synthesis and the full compatibility reading.
Birth data precision matters here
Synastry aspects between fast-moving planets — Moon, Mercury, Mars — depend on accurate birth times. The Moon moves about a degree every two hours, so a 30-minute uncertainty already shifts the reading.
If you don't have an exact birth time, the comparison still works at the slower-planet layer — Sun, Venus, the outer planets. We will tell you which aspects we are confident in and which we are not.
Aurathea's free synastry compares any two charts you enter — no saved-chart slot needed. See the base aspect layer (up to 10 aspects per pair) the moment you sign up. Studio adds the house overlay; Astrologer adds element + modality blends and the full compatibility score.