Synastry — Relationship Chart

What is Synastry?

Synastry is the branch of astrology that studies relationships by comparing two natal charts. The word comes from the Greek syn (together) and astron (star) — literally "stars together." Unlike simple Sun sign compatibility, synastry analyzes how every planet in one person's chart relates to every planet in the other's, revealing a complex web of attraction, challenge, long-term potential, and karmic connection between two souls.

This technique has existed for over two millennia. Ancient Greeks and Romans used it before arranging marriages, and today synastry remains the most sought-after tool in relationship astrology — used by professional astrologers and couples worldwide.

How Synastry Works

Astrologers overlay two natal charts and study the interaspects — the angles that one person's planets form with the other's. Each aspect tells its own story:

• Conjunction (0°) — A merging of energies. The most intense connection between two planets. One person's Sun on the other's Moon indicates deep emotional recognition.
• Trine (120°) — Harmonious flow. Natural understanding without effort. One person's Venus trine the other's Mars creates easy romantic chemistry.
• Sextile (60°) — Friendly support and shared opportunities for growth.
• Square (90°) — Friction and challenge. A harder aspect, but often the source of passion and dynamics that prevent a relationship from growing stale.
• Opposition (180°) — Polarity and the attraction of opposites. Can bring balance but also frustration.

Key Points in Synastry

Professional astrologers pay special attention to the following connections between charts:

• Sun-Moon contacts — The foundation of any relationship. If one person's Sun touches the other's Moon, it indicates deep compatibility between identity and emotion.
• Venus-Mars contacts — Romantic and sexual attraction. Aspects between these two planets determine chemistry and passion.
• Saturn aspects — Seriousness and longevity. One person's Saturn on the other's Sun or Venus suggests a karmic, long-term bond — but requires maturity.
• Pluto aspects — Transformative intensity. Pluto brings deep change, possessiveness, but also the potential for complete regeneration.
• North Node — Karmic destiny. One person's planets on the other's nodes indicate connections with a spiritual purpose.
• Ascendant contacts — Physical attraction and first impressions. Shows how your partner perceives you at first sight.

Beyond Aspects — Houses

In addition to aspects, synastry analyzes which houses a partner's planets fall into. If someone's Sun lands in your 7th house (the house of partnership), that person activates your capacity for relationships. If it falls in the 10th house, that person influences your career and public image. Houses reveal where in your life a partner makes the greatest impact.

Frequently Asked Questions

Do difficult aspects mean a bad relationship? No. Some of the longest-lasting couples have challenging aspects. Squares and oppositions create dynamism and passion. Relationships without any hard aspects can be pleasant but may lack depth.

Is an exact birth time necessary? For a complete analysis — yes, because birth time determines the houses and Ascendant. Without an exact time, the interaspects between planets are still valid, but you lose house and angle information.

Example Synastry Interpretation