Synastry Aspects: How to Interpret Conjunctions, Squares, Trines, Oppositions and Sextiles

When reading a synastry chart, aspects are some of the first things we look at. An aspect is the angle formed between two planets. In synastry, it helps us understand how one person’s planet interacts with the other person’s.

And depending on the aspect, that interaction can feel completely different. Some aspects create a lot of ease, while others bring more tension, stimulation or contrast. Some can create a very natural sense of understanding, while others highlight the areas where both people may need to meet each other halfway.

But there’s one important thing to keep in mind: an aspect is never inherently good or bad. A square can be challenging in certain areas, while also creating a great deal of movement or attraction. A trine can make a dynamic feel incredibly smooth without necessarily making the relationship strong or deep.

What matters is always which planets are involved, how strong the aspect is, which houses are involved and what the rest of the synastry chart is showing.  (If you're new to synastry, I recommend starting with my complete guide on how to interpret a synastry chart as a whole.)

 

What Are the Main Aspects in Synastry?

There are five major aspects we look at most often: the conjunction, opposition, square, trine and sextile.

Each one describes a different way for two planets to interact.

The Conjunction +

A conjunction occurs when two planets are very close to one another. It generally creates a very strong connection between the two planetary energies involved. The planets blend together, reinforce one another or come into very direct contact.

But a conjunction isn’t automatically harmonious. For example, a Moon-Venus conjunction can create a lot of warmth, affection and emotional security. A Mars-Saturn conjunction, on the other hand, can feel much more demanding, with a sense of restriction, frustration or pressure.

What they have in common is the intensity of the contact: the two planets are strongly connected, and their interaction is rarely insignificant within the relationship.

The Opposition +

An opposition occurs when two planets sit opposite each other in the zodiac.

In astrology, it often creates a dynamic of polarity: the two people may be very aware of their differences while also feeling strongly drawn to one another.

There can be something very complementary about an opposition. The other person brings a different way of functioning into the relationship, sometimes precisely in an area where we lack perspective or balance. But those differences can also create tension. Each person may feel as though the other operates in the opposite way, or takes an energy too far in a direction they experience differently.

So an opposition isn’t necessarily conflictual. More than anything, it describes an axis that needs to be balanced between two different ways of functioning that are constantly responding to one another.

The Square +

A square is an aspect of tension. It occurs when two planets are roughly 90 degrees apart and often highlights an area where the two energies struggle to move in the same direction.

It can create frustration, misunderstandings or the feeling that the other person keeps pressing exactly where there is resistance. But a square can also be a very dynamic aspect. It creates movement, pushes people to react, sometimes forces them out of their usual patterns and can generate a great deal of attraction depending on the planets involved.

A square therefore isn’t necessarily something to avoid. It mainly points to an area of the relationship that requires more adjustment and where things rarely feel neutral.

The Trine +

The trine is often associated with a strong sense of ease. When two planets form a trine, their energies tend to flow naturally. In synastry, this can create a sense of natural understanding, as though certain things simply don’t need much explanation.

You may feel comfortable with the way the other person expresses the planet involved, and this part of the relationship can feel relatively easy to navigate.

That said, this ease shouldn’t be overinterpreted. A trine can feel supportive and pleasant without necessarily creating a great deal of intensity or transformation. It mainly shows an area where the two people tend to work well together without having to force it.

The Sextile +

The sextile is also a relatively harmonious aspect, but it works a little differently from the trine.

It generally shows a potential for cooperation and complementarity between two planets.

The connection is there, but it may need to be activated a little more. While a trine can feel almost automatic, a sextile is more like an opportunity that both people can choose to make use of.

It can make communication easier, create curiosity about the other person or highlight areas where two people can naturally encourage each other and grow together.

A sextile is therefore often very pleasant in a relationship, but it still needs to be interpreted within the context of the chart as a whole.

 

How to Interpret a Synastry Aspect

To interpret a synastry aspect, you always need to look at three things at the same time: the planets involved, the type of aspect and how exact it is.

The Two Planets Involved +

The planets tell us which part of the relationship is being activated. A connection between the Moon and Mercury will mainly tell us about the way emotions and communication interact. A connection between Venus and Mars will have more to do with attraction, desire, seduction and the way each person moves toward the other.

So before even looking at the type of aspect, we first need to understand what the two planets coming into contact actually represent.

The Type of Aspect +

The type of aspect tells us how these two energies are going to interact. A conjunction creates a very direct connection between the two planets. A square introduces more tension or friction. An opposition creates a dynamic of polarity. A trine allows the two energies to flow more easily, while a sextile tends to show cooperation or complementarity.

In other words, the planets tell us what we’re talking about, while the aspect tells us how it plays out between them.

How Exact the Aspect Is +

Finally, we look at how close the aspect is to its exact angle. The more exact an aspect is, the more noticeable it generally tends to be within the relationship. Two planets forming an almost exact square will therefore usually attract more attention than the same square with a much wider distance from the exact angle.

This is what we call the orb, and we’ll come back to it just below.

Let’s take a simple example: a Venus-Mars connection already tells us that we’re dealing with attraction, desire and the way two people move toward one another.

But a Venus-Mars conjunction won’t feel the same as a Venus-Mars square or a Venus-Mars trine.

The planets are the same. What changes is the way their energies meet.

 

 

So, what does your synastry say about you two?

 

What Is an Orb in Synastry?

In astrology, two planets don’t need to be positioned at exactly 90°, 120° or 180° to form an aspect. We allow a small margin around the exact angle: this is called the orb. For example, a square corresponds to an angle of 90°. If two planets are 88° or 92° apart, they can still be considered square.

The orb therefore tells us how exact an aspect is. The closer an aspect is to its exact angle, the more noticeable it generally tends to be within the relationship. An aspect with a 1° orb will therefore often draw more attention than the same aspect with a much wider orb.

But there isn’t one single rule that should be applied mechanically. The orb we allow can vary depending on the planets involved, the type of aspect and the points being considered. Contacts involving the Sun, Moon or certain angles may, for example, be interpreted using a different margin than aspects involving other planets.

The main thing to remember is simple: the orb helps us understand how exact an aspect is, and therefore how much weight we may want to give it when interpreting the synastry chart.

 

Sun Aspects in Synastry

In synastry, the Sun speaks to identity, the way each person expresses themselves and the extent to which they feel seen and recognized by the other. Its aspects therefore show how one person may support, stimulate, attract or sometimes challenge the other person’s way of being.

Here are some of the main Sun aspects to explore:

  • Sun conjunct Moon: can create a strong sense of complementarity between one person’s identity and the other person’s emotional world.

  • Sun opposite Moon: often highlights two different ways of functioning, with a strong awareness of one another and a real dynamic of polarity.

  • Sun square Moon: can create a mismatch between what one person wants to express and what the other person needs emotionally.

  • Sun sextile Moon: generally supports a fairly natural flow between self-expression and emotional needs.

  • Sun conjunct Venus: often brings a great deal of appreciation, affection and a natural attraction to the other person’s way of being.

  • Sun square Venus: can show genuine attraction, but also differences in the way each person loves, attracts or expresses affection.

  • Sun conjunct Mars: often creates a lot of energy, stimulation and sometimes strong attraction, but can also make the relationship more competitive.

  • Sun conjunct Saturn: can bring seriousness, structure and a sense of responsibility to the relationship, although it may sometimes feel heavy or restrictive.

  • Sun square Saturn: can bring up tension around self-expression, boundaries, expectations or the feeling of being held back by the other person.

  • Sun trine Saturn: generally supports stability, reliability and the ability to build something over time.

  • Sun conjunct Pluto: can create a very intense connection in which one person deeply affects the other’s identity and capacity for transformation.

  • Sun opposite Pluto: often brings strong dynamics around power, attraction, resistance or transformation into the relationship.

  • Sun square Pluto: can create a great deal of intensity, with themes around control, self-assertion or simply finding it difficult to remain unaffected by the other person.

  • Sun trine Pluto: can create a deep but more fluid influence, with the potential to encourage the other person to grow or step more fully into their own personal power.

  • Sun conjunct Neptune: can create fascination, idealization, inspiration or a feeling of connection that is difficult to explain rationally.

  • Sun trine Neptune: often brings intuitive understanding, sensitivity and a sense of softness or inspiration to the connection.

  • Sun conjunct Lilith: can create a very strong attraction to something instinctive, free or difficult to contain in the other person.

  • Sun square Lilith: can bring up tension between one person’s identity and the more instinctive, independent or unsettling qualities Lilith awakens in the other.

  • Sun conjunct Chiron: can touch very sensitive areas of identity, with the potential to bring certain wounds to the surface and make them more conscious.

 

Moon Aspects in Synastry

In synastry, the Moon speaks to our emotional needs, our instinctive reactions and the way we seek to feel understood, reassured and emotionally safe in a relationship. Its aspects therefore show how the other person touches this very intimate part of us.

Here are some of the main Moon aspects to explore:

  • Moon conjunct Venus: can create a great deal of warmth and affection, along with a natural feeling of being emotionally appreciated and cared for.

  • Moon square Venus: can show a mismatch between one person’s emotional needs and the way the other expresses affection or tries to create harmony.

  • Moon trine Venus: generally supports a very natural emotional flow, with a strong sense of tenderness, understanding and emotional comfort.

  • Moon sextile Venus: often makes affection easier to express and encourages both people to be caring toward one another, with a softer and more cooperative dynamic.

  • Moon conjunct Mars: often creates a great deal of emotional reactivity and intensity, with a strong ability to energize one another but also to trigger quick reactions.

  • Moon opposite Mars: can heighten attraction and intensity while also creating tension between one person’s emotional needs and the other’s way of acting or reacting.

  • Moon square Mars: can make reactions more heated, with frustration or conflict arising quickly when one person’s emotions meet the other’s impulsiveness.

  • Moon trine Mars: generally creates a good flow between emotion and action, with a natural ability to support, motivate and respond to one another.

  • Moon sextile Mars: can create a lively and stimulating dynamic, with a good balance between sensitivity and taking action.

  • Moon opposite Moon: highlights two very different ways of feeling and reacting, which can create real complementarity but also require emotional adjustment.

  • Moon square Moon: can show emotional needs that don’t naturally align, with instinctive reactions that may sometimes be difficult for the other person to understand.

  • Moon conjunct Lilith: can create an intensely instinctive emotional connection, with heightened sensitivity to the rawer or freer parts the other person brings out.

  • Moon trine Lilith: can make it easier to express more instinctive emotions or feelings that are usually kept hidden, with a sense of greater emotional freedom.

  • Moon conjunct Ascendant: can create an immediate feeling of familiarity and closeness, as though one person instinctively understands the way the other presents themselves to the world.

  • Moon trine Ascendant: generally supports a natural understanding between emotional sensitivity and the spontaneous expression of personality.

  • Moon conjunct Midheaven: can create a strong connection between one person’s emotional world and the other person’s life direction, public image or ambitions.

  • Moon conjunct IC: can strongly reinforce feelings of familiarity, intimacy and emotional safety, with a sense that the other person touches something very deep and personal.

 

Venus Aspects in Synastry

In synastry, Venus speaks to the way we love, what attracts us, what we appreciate about the other person and how we give and receive affection. Its aspects are therefore particularly revealing when we want to understand attraction, tenderness, the pleasure of being together and certain emotional expectations within the relationship.

Here are some of the main Venus aspects to explore:

  • Venus conjunct Mars: can create strong attraction, with a very direct meeting between desire, seduction and the way each person loves.

  • Venus sextile Mars: often supports a natural complementarity between affection and desire, with attraction that flows fairly easily.

  • Venus trine Mars: can bring a lot of ease to physical and romantic attraction, with a natural sense of being drawn to one another.

  • Venus opposite Mars: often creates strong polarity and attraction, but can also reveal differences in the way each person experiences desire or pursues the other.

  • Venus square Mars: can generate strong sexual tension and stimulation, but also more frustration or mismatch between desire and affection.

  • Venus conjunct Saturn: can bring a great deal of seriousness to the emotional bond, with a desire to build something together, although feelings may sometimes feel restrained or heavy.

  • Venus trine Saturn: generally supports stability, reliability and a natural ability to build something lasting on an emotional level.

  • Venus square Saturn: can bring frustration, distance or the feeling that affection isn’t always being given or received in the way one person needs.

  • Venus conjunct Jupiter: often brings generosity, enthusiasm and a lot of pleasure in being together, with a tendency to amplify everything you appreciate about one another.

  • Venus sextile Jupiter: generally supports a warm, optimistic and encouraging emotional dynamic.

  • Venus conjunct Uranus: can create very fast, exciting and sometimes unexpected attraction, with a strong need for novelty or freedom within the connection.

  • Venus opposite Uranus: can make attraction feel very strong but harder to stabilize, with periods of closeness followed by distance.

  • Venus conjunct Neptune: can create a great deal of romance, fascination and idealization, sometimes with a tendency to project a lot onto the other person.

  • Venus trine Neptune: often supports tenderness, sensitivity, romance and an intuitive understanding of the other person’s emotional expectations.

  • Venus sextile Neptune: can bring delicacy, inspiration and sensitivity to the way two people love one another.

  • Venus conjunct Pluto: can create extremely intense attraction, with a feeling that the connection touches something deep and sometimes difficult to control.

  • Venus square Pluto: can strongly intensify desire and attachment, but may also bring up jealousy, control or power dynamics.

  • Venus conjunct Chiron: can touch very sensitive areas connected to love, self-worth or feeling loved, with a strong ability to bring certain wounds to the surface.

  • Venus trine Chiron: can create a gentler way of touching and holding the other person’s emotional vulnerabilities within the relationship.

  • Venus square Chiron: can more directly bring up wounds connected to love, rejection, self-worth or the way each person gives affection.

  • Venus conjunct Lilith: can create very instinctive, magnetic attraction that is difficult to rationalize, with something freer or more raw in the desire between two people.

  • Venus opposite Lilith: can heighten fascination and polarity, with tension between one person’s way of loving and the more instinctive side the other person awakens.

  • Venus square Lilith: can create a great deal of attraction, but also tension around desire, freedom, boundaries or what each person feels comfortable owning within the relationship.

  • Venus trine Lilith: can make it easier to express a more instinctive sensuality and to embrace attraction more freely.

  • Venus conjunct Sun: often creates strong appreciation for the other person’s personality, with a lot of affection and the feeling of naturally loving who they are.

  • Venus square Sun: can create attraction while also highlighting differences between identity, emotional expectations and the way love is expressed.

  • Venus sextile Venus: often shows compatible tastes, values or ways of loving, even if they aren’t completely identical.

  • Venus trine Venus: generally supports a great deal of ease around tastes, affection and the way two people create pleasure together.

  • Venus square Venus: can show different ways of loving, flirting or giving affection, requiring more adjustment between the two people.

  • Venus conjunct Mercury: often makes it easier to express affection through words and can create a lot of enjoyment in conversation.

  • Venus trine Mercury: supports pleasant communication and a natural ability to express what you appreciate about one another.

 

Mars Aspects in Synastry

In synastry, Mars speaks to desire, physical attraction, drive, action and the way each person asserts their needs. Its aspects can therefore tell us just as much about the chemistry between two people as about the way they stimulate one another, clash or deal with frustration.

Here are some of the main Mars aspects to explore:

  • Mars conjunct Venus: can create very direct attraction, with a strong meeting between desire and seduction.

  • Mars square Venus: often generates a lot of sexual tension, but can also create frustration when desire and the way love is expressed don’t move at the same pace.

  • Mars opposite Venus: can strongly heighten attraction and polarity while also revealing differences in the way desire is pursued or received.

  • Mars trine Venus: generally supports fluid attraction and a natural complementarity between desire and affection.

  • Mars conjunct Moon: can create a great deal of emotional reactivity and stimulation, with quick responses between the two people.

  • Mars square Moon: can make emotional exchanges more heated, especially when one person’s actions or impulsiveness clash with the other person’s emotional needs.

  • Mars opposite Moon: can create strong tension between emotional reactions and action, bringing a lot of intensity but also requiring adjustment.

  • Mars trine Moon: often creates an easy flow between emotion and action, with a natural ability to support and motivate one another.

  • Mars sextile Moon: can bring a lively and constructive dynamic, with a natural balance between sensitivity and initiative.

  • Mars conjunct Mercury: generally makes communication lively, direct and stimulating, with a great deal of mental energy between the two people.

  • Mars square Mercury: can lead to more impulsive conversations, quick words or a tendency for certain disagreements to become confrontational.

  • Mars conjunct Jupiter: can create a great deal of enthusiasm and energy, along with a strong desire to act, explore or take things on together.

  • Mars square Jupiter: can push things too fast or too far and amplify certain reactions, creating a very stimulating but sometimes excessive dynamic.

  • Mars conjunct Saturn: can create strong tension between action and restraint, sometimes with the feeling that one person is pushing while the other is applying the brakes.

  • Mars trine Saturn: generally supports the ability to channel energy effectively and turn impulses into more structured action.

  • Mars square Saturn: can generate a great deal of frustration, especially when one person feels limited, blocked or constantly held back by the other.

  • Mars conjunct Uranus: can make the relationship highly stimulating, unpredictable and electric, with a strong urge to act differently or break out of routine.

  • Mars square Uranus: can heighten impulsiveness, sudden reactions or tension around freedom and control.

  • Mars conjunct Lilith: can create strong instinctive and sexual intensity, with something very direct in the desire and the way the two people provoke one another.

  • Mars square Lilith: can bring up a lot of tension, desire and resistance around boundaries, power or freedom of action.

  • Mars trine Lilith: can make it easier to express desire and a more instinctive kind of energy, with less restraint between the two people.

  • Mars conjunct Ascendant: often creates a strong immediate impression, with a great deal of energy, attraction or stimulation from the very beginning.

  • Mars opposite Ascendant: places Mars close to the Descendant and can therefore strongly activate the relationship dynamic, creating plenty of attraction but also potential confrontation.

 

How to Use This Synastry Aspect Index

The easiest way is to start with the planet or planetary combination you’re interested in, then open the dedicated page for that specific aspect.

The same pair of planets can tell a very different story depending on whether they form a conjunction, square, trine or opposition. That’s why each aspect deserves to be interpreted separately.

And if you want to understand your synastry chart as a whole, rather than one individual aspect, you can also read my complete guide to interpreting romantic synastry.

 

What If You Want to Understand All Your Aspects Together?

Reading one aspect on its own can already shed light on part of a relationship. But what becomes really interesting is seeing how all those aspects work together.

That’s exactly what NOUS, Mode d’emploi does: we don’t stop at a Venus-Mars square or a Moon-Venus conjunction. We look at your entire synastry chart to understand what brings you closer, what creates attraction, where tension can arise and which patterns keep showing up in your relationship.

The idea isn’t to give you a compatibility score, but to help you understand how the two of you actually work together.

 

So, what does your synastry say about you two?