AstraLinkVenus conjunct Mars
The headline chemistry aspect.
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Synastry aspects: the contacts that make two charts click
Synastry compares two birth charts, and the aspects between your planets and someone else's are where the chemistry lives. This hub explains what synastry aspects are, which planets and angles matter most for love, and links to in-depth reads on the specific contacts people search for.
Quick answer
Synastry aspects are the angles formed between one person's planets and another's when their birth charts are overlaid. They show how two people's energies interact: conjunctions fuse, trines and sextiles flow, squares and oppositions create tension. The contacts that matter most for love involve the Sun, Moon, Venus, Mars, Saturn and the Ascendant.
What is a synastry aspect?
When two people's birth charts are laid over each other, their planets form angles — aspects — to one another. Those cross-chart aspects are the heart of synastry: they describe how your Venus meets their Mars, how your Moon meets their Saturn, and so on. Each contact is a thread of connection with its own flavour.
The five major aspects carry most of the meaning:
- Conjunction (0°) — fusion. The two planets act as one; intense and defining.
- Trine (120°) — easy flow. The energies support each other with little effort.
- Sextile (60°) — gentle opportunity. Supportive, if you reach for it.
- Square (90°) — friction. Attraction with tension; growth through challenge.
- Opposition (180°) — magnetism and mirror. You complete and confront each other.
Which planets matter most in love
Not every contact is equal. For romantic compatibility, the planets to watch are:
- Sun — identity and vitality; contacts show recognition and pride in each other.
- Moon — emotional needs; Moon contacts are the glue of comfort and safety, often the strongest sign of a lasting bond.
- Venus — love and attraction; the pleasure and affection between you.
- Mars — desire and drive; the Venus–Mars contacts especially are the chemistry aspects.
- Saturn — commitment and time; Saturn contacts add weight and durability, or restriction if harsh.
- The Ascendant — the instant "I see you"; planets on the Ascendant create immediate recognition.
- The lunar nodes — the sense of fated, destined connection.
A relationship that lasts usually has a mix: chemistry (Venus–Mars), comfort (Moon), and staying power (Saturn or the nodes). Chemistry alone is a spark, not a fire.
Read the specific contacts
Each aspect below is one thread. The real picture is the sum of all of them, which is what AstraLink's Cosmic Dating and compatibility reading scores — Venus, Mars, Moon, Saturn and the house overlays together — so you see whether there is chemistry and a relationship.
How two charts are compared
The five connections that carry the most weight in a compatibility reading, scored and explained.
Venus → Mars — Attraction & desireMoon ↔ Moon — Emotional safetySun ↔ Moon — Being understoodSaturn contacts — Commitment & staying power7th-house overlay — The partner you recognize
Popular synastry aspects
In-depth reads on the contacts people search for most.
Sun conjunct Moon
Identity meets emotion; a classic bond.
Moon conjunct Moon
Two hearts that need the same things.
Moon conjunct Venus
Tenderness and easy affection.
Venus square Mars
Attraction with friction.
Venus conjunct Saturn
Love that commits — or restricts.
Sun conjunct Venus
Warmth, admiration, ease.
Mars conjunct Mars
Shared drive — teamwork or rivalry.
North Node conjunct Venus
The fated-love contact.
Synastry aspect questions
What are the most important synastry aspects?
For love, the most important contacts involve the Sun, Moon, Venus, Mars, Saturn and the Ascendant. Moon contacts show emotional comfort and are among the strongest signs of a lasting bond; Venus and Venus–Mars contacts show affection and chemistry; Saturn contacts and the lunar nodes show commitment and a sense of destiny. A durable relationship usually blends chemistry, comfort and staying power rather than relying on one.
Which synastry aspects show strong attraction?
The classic attraction aspects are Venus–Mars contacts (especially the conjunction), Sun–Venus, Mars on the Ascendant, and Pluto–Venus for intensity. These describe physical and romantic pull. Attraction aspects are exciting but incomplete: they say nothing about emotional safety or shared values, so they are best read alongside Moon, Mercury and Saturn contacts that show whether the spark has anything steady to stand on.
Are hard synastry aspects (squares, oppositions) bad?
No. Squares and oppositions create tension, but tension is often what makes a connection feel alive and magnetic. Many long relationships are full of hard aspects that keep two people engaged and growing. The difference between productive and painful friction usually comes down to the softer contacts around it and to two people's willingness to work with the charge rather than against each other.
How do I read my synastry aspects?
Overlay both birth charts and list the aspects between your planets and your partner's, noting the planets involved, the aspect and how tight the orb is. Weight the personal planets (Sun, Moon, Venus, Mars) and the angles most heavily. Then read the whole pattern rather than cherry-picking one contact. The compatibility calculator and Cosmic Dating do this automatically, scoring the full set from two birth dates.
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AstraLink content is written by our editorial team, reviewed for astrological accuracy, and refreshed as the sky moves. Interpretations are for reflection and entertainment; they are not medical, legal or financial advice.