Two planets never express themselves in isolation within an astrological chart: it is the angle they form between them, called an aspect, that determines whether their energies reinforce one another, create tension, or dialogue with fluidity. Here is how to read these aspects, distinguish them, and a concrete example using Julie's chart.
What is an aspect in astrology?
An aspect is the geometric angle that two planets form with each other on the zodiac circle, measured in degrees. If the Sun is at 10° Aries and Mercury at 8° Gemini, the gap between the two is approximately 58°, which approaches a precise aspect: the sextile.
Each angular gap corresponds to a type of dialogue between the two planets involved. Some angles create a fluid circulation of energy, while others generate a tension that pushes toward action or adjustment. An astrological chart is therefore read as much through the position of each planet in a sign as it is through the network of aspects they weave between them.
Major aspects
Five so-called major aspects structure the essence of chart analysis. They are the most frequently studied because their influence is the most marked.
The conjunction (0°)
Two planets in conjunction occupy a nearly identical position in the zodiac. Their energies fuse: they function as a single force, difficult to dissociate in behavior. The conjunction is a neutral aspect in itself; its effect depends entirely on the nature of the planets combined.
The opposition (180°)
Two planets in opposition face each other from either side of the chart. They represent a polarity to be balanced, a tension between two needs or two ways of acting that seem contradictory but, once integrated, complement each other.
The square (90°)
The square creates friction between two planets. It is the aspect of friction and obstacles, but also that of the driving force: it pushes one to act, to surpass oneself, and to resolve an internal contradiction rather than passively enduring it.
The trine (120°)
The trine connects two planets of the same element most of the time. It translates into an easy flow of energy, a natural talent, a facility that requires no particular effort to express.
The sextile (60°)
Similar to the trine in its tone, the sextile is more discreet: it indicates an opportunity, an aptitude that needs to be engaged and developed to bear fruit, unlike the trine which expresses itself spontaneously.
| Aspect | Angle | Usual Orb | Nature |
| Conjunction | 0° | 8° to 10° | Neutral — depends on the planets combined |
| Sextile | 60° | 4° to 6° | Harmonic — opportunity to be seized |
| Square | 90° | 6° to 8° | Tense — friction, engine for action |
| Trine | 120° | 6° to 8° | Harmonic — natural ease |
| Opposition | 180° | 8° to 10° | Tense — polarity to be balanced |
Each line connects a reference planet (top) to a second planet positioned at the corresponding angle. Green: harmonic aspects. Terracotta: tense aspects. Gold: conjunction, neutral aspect to be interpreted according to the planets involved.
Minor aspects
Alongside the five major aspects, so-called minor aspects refine the analysis without ever taking precedence over them. Their orb is narrower, generally 1° to 3°, which limits their influence to nuances rather than central dynamics of the chart.
- Semi-sextile (30°): a discreet adjustment between two neighboring areas of life.
- Semi-square (45°): a dull friction, less visible than a square but just as irritating in the long run.
- Sesquiquadrate (135°): a tension that arises in bursts, often linked to external events.
- Quincunx or inconjunct (150°): two planets that struggle to understand each other because they have almost nothing in common, requiring a conscious effort of adjustment.
Minor aspects refine the reading of the chart without altering its structure. Terracotta: discreet tensions. Gray-brown: adjustments to be made consciously.
Harmonic and tense aspects: two complementary logics
| Aspect Type | What it provides |
| Trine, sextile | A natural flow of energy: ease, spontaneous talent, but sometimes also a comfort that does not encourage one to surpass oneself |
| Square, opposition | Friction that requires an effort of integration: uncomfortable at the moment, but often the true engine of transformation |
A chart rich in harmonic aspects is not necessarily more favorable than a chart marked by tensions: it is often the squares and oppositions that push one to develop strength of character, while an excess of harmonic aspects can result in a form of passivity. The balance between the two logics is what gives the chart its own unique dynamic.
The orb: a margin of tolerance
An aspect is rarely exact to the degree. The orb designates the margin of tolerance around the theoretical angle within which the aspect remains active. An exact square is at 90°, but a gap of 90° to 96° is still considered a square, with an intensity that decreases as one moves away from the exact angle.
The tighter the orb, the more powerful and perceptible the aspect is in the personality. Orbs vary slightly according to schools and the planets involved: the Sun and Moon, as luminaries, generally tolerate wider orbs than slower planets like Saturn or Pluto.
Concrete example: the aspects in Julie's chart
Let's revisit the chart of Julie, born on May 14 in Lyon (8:12 AM), already used to illustrate her dominant planets: Mercury, Pluto, and the Moon. It is precisely the network of aspects that largely explains why these three planets stand out as structuring elements.
The major aspects of Julie's chart
| Aspect | Orb | Reading |
| Moon trine Mercury | 3°45' | A natural circulation between emotion and thought: Julie intuitively understands what she feels and knows how to put it into words accurately, an asset for listening and analysis |
| Moon sextile Pluto | 4°13' | An intense emotional life that Julie experiences fully rather than enduring: she expresses her feelings frankly, even at the risk of causing some friction |
| Sun trine Saturn | 2°04' | A capacity for work and a sense of responsibility that structure the solar identity, even if Julie tends to be strict with herself |
It is the Moon-Mercury trine, with a tight orb, that directly connects two of Julie's three dominant planets: it explains why sensitivity and analysis function in tandem for her rather than in opposition. The Moon-Pluto sextile adds the third dominant to this network, linking emotion to a deeper intensity. Finally, the Sun-Saturn trine balances the whole: beneath mental and intense dominants, Julie maintains a solid foundation and a real capacity for work.
Frequently asked questions
Is a tense aspect necessarily negative?
No. A square or opposition creates friction, but it is precisely this friction that pushes one to act and to build oneself. Many personal successes rely on well-integrated tense aspects rather than on purely harmonic ones.
Why do some aspects not appear in my chart?
Not all planets necessarily form a major aspect with each other: if the angular gap does not fall within the orb of any recognized aspect, it is referred to as a non-existent or "out-of-orb" aspect, which is quite normal and frequent in a chart.
Is a precise birth time needed to calculate aspects?
Aspects between planets can be calculated without a precise birth time, unlike angularity or houses. However, an exact time remains useful for situating certain aspects in relation to the chart's angles (Ascendant, Midheaven).
Fancy finding out your full birth chart?
Your personalized astrological chart, calculated from your date, time, and place of birth, and explained in a book designed for you.
Discovering my Astrabook