More than two Sun signs
A magazine column compares two Sun signs, which gives you 78 possible pairings for everyone on Earth. Your Sun sign is real information in astrology, but it’s one point out of many. Synastry takes the position of every planet in your chart at the moment you were born and compares it with every planet in the other person’s chart.
So instead of “Leo and Pisces”, you get a list of specifics: your Moon is close to their Venus, their Saturn sits at a right angle to your Mars, your Sun and their Moon are in a gentle 120 degree angle. Two Leo and Pisces couples can have almost nothing in common once you look at this level.
The pieces it uses
Planets stand for parts of a person. The Moon is what you need to feel okay, Venus is how you love and what you enjoy, Mars is how you go after things, Saturn is where you take things seriously. In astrology the Sun and Moon count as planets, and so does the Ascendant, also called your Rising sign, for this purpose.
Signs describe the style a planet works in. Mars in Taurus goes after things slowly. Mars in Aries doesn’t.
Houses divide the sky around your birthplace into twelve areas of life. They depend on your birth time, and they show which parts of a chart are loudest.
Aspects are the angles between planets, and they do most of the work in synastry. Our guide to harmonious, challenging and dynamic aspects goes through them.
How MatchMachine does it
The app compares 11 points in each chart: the Sun, the Moon, the eight other planets from Mercury to Pluto, and the Ascendant if your birth time is known. It finds the aspects between your chart and theirs, gives planets in stronger houses a little more room, and also counts planets sitting in each other’s home signs, which astrologers call mutual reception. The slow outer planets aren’t compared with each other, since everyone born within a few years of you shares those positions.
That produces a score from 0 to 100 and a label, from Exploring up to Cosmic Match. Numbers alone don’t tell you much, so we wrote a description for each of the 66 possible planet pairs at each of the 5 major aspects, 330 in all. The reasons are grouped into five areas: emotional, communication, romance, passion and long-term.
What it can’t do
Synastry can’t tell you whether someone is kind, honest or ready for a relationship. It won’t say how things turn out. Two people with a lovely-looking comparison can still be wrong for each other, and people with a rough-looking one can build a good life together.
Think of it as a good conversation starter about how two people differ. It’s for reflection and for fun. When you want to go further, how to read a synastry chart is a good next step.