The Synastry Chart

A single birth chart is one person's sky. Synastry is what happens when you set two of those charts on top of each other and look at how they talk. It does not blend the two people into one new chart. It keeps both whole and studies the angles that form between your planets and theirs, the distances in the sky that astrology calls aspects. Where your Moon lands against their Sun, where your Venus meets their Mars, those contacts are the raw material of a relationship reading. Synastry is simply the discipline of reading them.

What an aspect is

Every planet sits at a degree around the circle of the zodiac. An aspect is the angle between two of them. A conjunction is the same spot, an opposition is across the circle, a trine and a square are the easy and the tense angles in between. In one chart, aspects describe a person. In synastry, the aspects run between two charts, so your planet and their planet make the angle. A close, exact angle speaks loudly. A wide one barely registers. The whole method is reading which planets reach across to each other and at what angle.

The bodies that carry a relationship

Not every contact weighs the same. The Moon carries feeling and comfort, so Moon contacts describe the emotional fit, whether you soothe each other or set each other off. Venus and Mars carry attraction and desire, so their contacts describe the charge, the pull, the spark. The Sun and the rising sign describe whether you simply see each other clearly. A strong synastry is rarely all ease. Often it is the mix of smooth contacts and friction that makes two people stick.

Why it starts with two real charts

You cannot run synastry from two sun signs. The angles depend on where every planet actually stood, and that means a full natal chart for each person, each needing a date, a time and a birthplace. Get the two charts right and the overlay is just geometry. Guess at them and the reading is guessing too. The honest version of synastry always begins by casting each person's real sky.