← Encyclopedia of Astrology · lesson 92/235
Aspects
What an aspect is
An aspect is an angle between two points in a chart, measured around the zodiac. If the Sun is at 10° Aries and the Moon at 10° Leo, they are 120° apart and make a trine. The word means a "look": two planets in aspect are said to behold one another, and so to act on each other. Planets with no aspect between them work more independently.
If the planets are the actors, the signs their manner and the houses the stage, the aspects are their conversations — where energies blend easily, where they collide, where they push one another to grow. Stephen Arroyo describes them as the dynamic interactions between the energies of a life.
The major aspects
Ptolemy recognised four aspects between signs — the opposition, trine, quartile (square) and sextile — and explained them by the ratios of music: the half, the third and the quarter of the circle. To these every tradition adds the conjunction, two planets together, which deVore notes is often classed as a position rather than an aspect. These five are the major, or Ptolemaic, aspects:
| Aspect | Angle | Division of the circle | Usually read as |
|---|---|---|---|
| Conjunction | 0° | 1 | fusion; depends on the planets |
| Sextile | 60° | 6 | opportunity, cooperation |
| Square | 90° | 4 | friction, effort, decisive action |
| Trine | 120° | 3 | ease, flow, natural talent |
| Opposition | 180° | 2 | polarity, awareness through the other |
Ptolemy called signs that make none of these "disjunct" or averse — those one or five signs apart, which do not "see" each other.
The minor aspects
Later astrologers, beginning with Kepler in the seventeenth century, added aspects built on finer divisions of the circle. The commonest are the semi-sextile (30°), semi-square (45°), quintile (72°), sesquiquadrate (135°), biquintile (144°) and quincunx (150°). They are read as subtler, and with much tighter orbs; the quincunx, which Ptolemy's scheme left out, has become important in modern practice and is the basis of the Yod.
Separate from all of these are the parallel and contraparallel, measured not around the zodiac but by declination, north and south of the celestial equator.
Hard and soft
Aspects are often sorted into two families. The hard (or dynamic) aspects — square and opposition, with the semi-square, sesquiquadrate and quincunx — bring pressure, friction and the push to act. The soft (or harmonious) aspects — trine and sextile, and the quintile series — bring ease and flow. The conjunction belongs to neither: it takes its tone from the planets involved. Authors disagree about the semi-sextile, which some count as mildly easy and others as a strain.
Neither family is simply good or bad. Ease can become complacency and friction can become achievement; many astrologers find that the hard aspects drive a life forward while the soft ones show what comes naturally.
How close is close enough
Planets are rarely at an exact angle, so each aspect is allowed an orb: a margin either side of exact within which it still counts. A tighter aspect is generally read as louder — see aspect strength. Whether the planets are closing on the exact angle or drawing apart is the difference between applying and separating, and the moment of exactness matters most in forecasting. Most modern astrologers measure aspects by degree, so two planets can aspect across a sign boundary — an out-of-sign aspect; the Hellenistic astrologers more often reckoned aspects by whole signs.
When three or more planets are linked by aspects into a shape — a T-square, a Grand Trine, a Kite — the figure is read as a whole: see aspect patterns.
How aspects are shown here
The charts here calculate the five major aspects and six minors: the semi-sextile, semi-square, quintile, sesquiquadrate, biquintile and quincunx, with parallels and contraparallels in their own table. The Aspects table lists each pair with the aspect, its orb, whether it is applying, and its strength; aspects to the asteroids can be included with a tick box. On the wheel each aspect is drawn as a coloured line between the two bodies, and a key can name the colours.
In forecasting readings, the ease and tension chart counts trines, sextiles, semi-sextiles and the quintile series as ease, squares, oppositions, quincunxes, semi-squares and sesquiquadrates as tension, and reads a conjunction by the planet making it.