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Astrology of relationships: Chemistry vs Compatibility

Chemistry compatibility matrix Mark Manson

I've done quite a few posts about the Astrology of relationships, form covering the most under-rated and over-rated aspects, to discussing myths and compatibility criteria. Today, I want to talk about how to assess a relationship's compatibility and chemistry.


Chemistry is an unexplainable attraction and spark, which has its roots in the appreciation of differences we share with our partner. Chemistry remains largely mysterious, but research has shown In Astrology, this means Mars, Venus, and hard aspects.

Aspects for chemistry in Astrology

In order for a relationship to have chemistry, the dizzying lust and attraction that makes us sick (in love?), we need to find contacts, and if possible hard, with Mars, Moon, Sun, Venus. So typically, a Mars-Venus contact, even hard, will do. Or a Mars-Mars contact. Or a Moon-Mars contact. Or a Sun-Venus contact. The square Sun-Venus in particular has a strong sexual appeal, whereas a Sun-Venus trine would be more so a compatibility sign and a genuine friendship and appreciation of each other. Sun trine Venus is more compatible, while Sun square Venus is lustier.

Overall, difficult aspects between inner planets will bring a lot of heat, some conflict, and a lot of attraction. So a Mars square Mars in synastry will get you super hot but also bothered, a Venus square Sun will bring much more heat than a trine, a Venus square Mercury could bring passionate debates and arguments that leave you infatuated despite the conflict.

Pluto and chemistry

Now usually, Pluto is always quoted as a chemistry component of a relationship, but I don't find it to be a straightforward thing to say. Pluto indicates devotion and passion yes, it also represents power plays, attachment, betrayal and trauma. So I'm not usually so keen to find a Pluto-heavy synastry. I find Pluto relationships to be exhausting, so I would focus on inner planets when it comes to chemistry.

Chemistry and compatibility

Now obviously, as much as these aspects create chemistry, they can also indicate major incompatibility. In order to determine whether or not the relationship is doomed to burn down, you'll need to evaluate a few things:

- Are there also elements of strong compatibility in the synastry?

- Are the two partners people who have a "heated" birth chart themselves, showing an appeal for passionate relationships and (healthy) conflict? Are they both inclined to appreciate passion and heat over comfortable nests?

- Do the synastry and both birth charts indicate a desire and capacity to commit to a long work of adapting to each other? High chemistry involves necessarily more potential for conflict, which means we also need two individuals committed to working through differences and individuals who also have a solid compatibility.


Fluid aspects for compatibility

There are several ways of assessing compatibility, in my opinion. The most popular one is to appreciate flowy aspects between charts. This is your typical Moon trine Moon, Moon trine Sun, Sun trine Venus, an abundance of supportive aspects between luminaries (sextile, trine, conjunctions between soft planets). I'm not going to repeat what most of you have already read.

Saturn for compatibility

I will say, in terms of compatibility by aspects, I think the most important things are supportive aspects between Saturn and inner planets, and supportive aspects between Jupiter and inner planets. Supportive aspects of Neptune are also desirable. Why? A relationship with high chemistry and a highly positive Saturn will have a strong backbone to work with, they will both display commitment and devotion to working through differences. Same goes for Jupiter, it will create a feeling that the relationship inspires growth, vision, and a mutual expansion.

Typically, you'd want to find a double Saturn-Sun, or double Saturn-Venus, or even a double Saturn-Moon. Saturn to Jupiter are also stellar aspects to find in synastry.

Neptune has another function, easy aspects of Neptune tend to create a capacity to forgive and forget, accept and transcend, which can be incredibly useful in relationships.

I'm purposely leaving Pluto and Uranus out of the equation. They can bring passion, fun, devotion, friendship, but I don't find them to be necessary in terms of compatibility or chemistry.

Similarities in between birth charts for compatibility

Another basic but often forgotten way of assessing compatibility is to care for the energy instead of the aspects. So for example, if you're a Libra Moon and your partner has a 7th house Moon, you do have some common grounds as you both value relationships and compromise a lot, even if your Moons are not forming an aspect to each other.

Similarly, if you are a Leo Sun and your partner has a Sagittarius rising, even if these two don't touch by aspect, they still very much so resonate with each other.

If you have a Cancer Mars and your partner has Mars in the 4th house, yet again, you would share some similarities. Equally, if you have Mars conjunct Moon, you would also have some common patterns with your partner who has Mars in Cancer (This is because Moon is the ruler of Cancer. If you do not understand this point, I highly recommend you sign up for the Astro School!)

The same goes if let's say, you have Mercury in Virgo and your partner has Venus in Scorpio, there is basic compatibility at play, even if Mercury and Venus are not in orb to be in aspect to each other.

Shared patterns for compatibility

Another way to assess if your partner and you have compatibility is to track similar patterns. Now the problem with this method is that we almost always pick partners who have similar patterns than us, the key is to pick a partner who mirrors our positive patterns.

Patterns are determined by aspects. If you have Neptune square Mercury in your chart, that is a pattern you have in terms of communication. This is not necessarily an easy one, and picking a partner who also has Neptune in hard aspect to Mercury is going to create a mirror, however, it will be a difficult and painful one.

If you have Moon trine Jupiter, you are someone who has for pattern to be emotionally abundant and uplifting. You have a big heart. If your partner also has a Moon-Jupiter pattern, even if you do not have aspects between your Moon, you will feel a strong sense of compatibility with them. If you would like to learn how to assess compatibility yourself, check out my Astrology Compatibility class!

See also:

Relationship & synastry:


3 commentaires

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24 févr. 2021

"Compatibility by basic compatibility"

Yes!! Someone finally said that! Astrologers nowadays are so stuck with complicated synastry aspects that they forget about the basic. My sister and brother in law barely have aspects in their synastry chart lol but they're one of the harmonious couple I've ever seen. Their Suns are compatible (Leo and Gemini), their Moons are compatible (Aquarius and Libra), their Mercury are quite compatible I guess (Virgo and Gemini), their Mars are compatible (Taurus and Picses).

Several of my love life experiences and friendships are also like that, don't have many aspects, but hit it off like crazy.

Funnily though, I have a childhood friend that was born a day after me, and an acquaintance in high…

Julia Topaz
Julia Topaz
11 mars 2021
En réponse à

I agree! I have a friend who has the most peaceful and compatible relationship, they do not share many aspects between charts however almost everything is compatible by sign/nature. Underrated for sure!


20 déc. 2020

I wonder if the Saturn quintile North Node aspect has any weight in synastry. Would love to see a post about anything quintile, natal or synastry =)

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