Square aspect: the 90° angle in a birth chart

A square is an aspect between two points of a chart that stand 90° apart along the ecliptic. Together with the conjunction, sextile, trine and opposition it belongs to the five aspects known as Ptolemaic, which is why it counts as a major aspect. Modern astrologers call it a hard or tense aspect: the two planets pull in different directions, and the person experiences that as friction that asks for action.

Geometry: why 90°

The ecliptic divides into four equal quarters, and each quarter spans three signs of the zodiac. In a classic square the planets therefore sit in signs with two other signs between them: Aries and Cancer, Taurus and Leo, Gemini and Virgo.

One useful property follows from this. Signs in square belong to the same modality (cardinal, fixed or mutable) but to different elements. Aries and Cancer are both cardinal, yet one is fire and the other water. Same tempo, different nature: that is why a square reads as a clash between two ways of acting rather than a clash of goals.

The square sits between the sextile (60°) and trine (120°) on one side and the opposition (180°) on the other. On the wheel it looks like a right angle, and most chart software draws it in red, like the opposition.

The orb of a square

An exact 90° is rare, so astrologers allow a margin called the orb. There is no single standard. Most schools give the square an orb of about 6-7° between personal planets, up to 9° with the Sun or Moon. The tighter the orb, the stronger the aspect: a square within 1° shows in the character more clearly than one within 7°.

The AstroWay calculator does not use one orb for everything; it sets the orb by the pair of planets. That is why the aspect table of every chart shows each square with its actual orb.

Waxing and waning squares

In every pair one planet is faster than the other. When the faster planet has moved 90° ahead of the slower one in zodiac order, the square is called waxing. When it has already passed the opposition and is closing in on the slower planet from the other side, the square is waning.

The Moon shows this most simply. The first quarter Moon is a waxing square of the Moon to the Sun, the last quarter is a waning one. Astrologers who work with phases read the waxing square as a crisis in action: something has started and now has to push through. The waning square is closer to a crisis in belief: the old approach no longer works and the new one has not appeared yet.

Out-of-sign squares

Sometimes two planets are nearly 90° apart while their signs do not form a square. A planet at 29° Aries and another at 1° Leo are 92° apart, a square by orb. But Aries and Leo are both fire signs, and by sign they form a trine.

This is called a dissociate or out-of-sign square. Most astrologers count it but read it more softly: the friction between the planets is there, the contrast of elements is not. The AstroWay aspect table lists it as an ordinary square, so it is worth checking the signs yourself.

What a square does in a chart

The square is often called a bad aspect. That is a simplification. Tension between two planets pushes a person to find a solution, and in many charts the squares describe exactly the area where the person works hardest and achieves something.

To read a particular square, look at three layers:

• Planets. Which two functions collide. Mercury stands for thinking and speech, Mars for action and will, Saturn for limits and structure. Mars square Saturn reads nothing like Venus square Jupiter.
• Signs. How each planet acts. Both signs share a modality, so in cardinal signs the tension shows through initiative, in fixed signs through stubbornness, in mutable signs through scattered effort.
• Houses. Where in life it plays out. A square between planets in the 10th and 1st houses ties the public role to personal behaviour.

It also matters whether the square is applying (the orb is shrinking) or separating (the orb is already growing). An applying aspect is traditionally considered stronger.

Squares in transits

A square is not limited to two planets of the birth chart. When a planet in today's sky reaches 90° from a natal planet, astrologers speak of a transiting square. The orb here is much tighter than in the natal chart, usually 1-2°, because a transit is an event in time and it is read when the angle is close to exact.

Transits of the slow planets, from Jupiter outward, get the most attention. The Moon and Mercury cross a square within hours or days, and it is hard to notice. A slow planet can form the same aspect two or three times in a year because of retrograde motion, and the whole stretch is then treated as one drawn-out period.

The waxing and waning distinction applies here too. Saturn takes about 29 and a half years to go round the zodiac, so it forms a waxing square to its own natal position at around age seven, a waning square at around 21-22 and another waxing square at roughly 36-37. Astrologers who work with cycles read these points as a test of whatever was set in motion at the start of the cycle.

A transiting square describes a theme that demands attention during that period, not a specific event. Which theme depends on the natal planet the transit touches and the house that planet occupies.

Example: the square in Donald Trump's chart

In Donald Trump's chart Mercury is at 8°51′ Cancer and Neptune at 5°50′ Libra. The angle between them is about 87°, the orb 3°01′, and the aspect is separating. Cancer and Libra are both cardinal signs, so this is a classic square within one modality: a water sign against an air sign.

How tradition reads the pair: Mercury rules words and the way of thinking, Neptune image, imagination and blurred boundaries. A square between them describes speech that leans toward images and broad strokes rather than a dry list of facts. This describes a type of thinking, not a verdict on the person.

It is the only square within AstroWay's orbs. The rest of the tension comes from oppositions: the Sun opposes the Moon, and the Moon opposes Uranus.

Squares in configurations

Several squares can combine into figures. Two squares meeting at one planet, plus an opposition between their other ends, form a T-square. Four planets joined by four squares and two oppositions form a grand cross. These figures are covered separately, because their meaning is more than the sum of the aspects.

In celebrity charts

The tightest examples among the published charts.

• Hillary Clinton: Mercury square Saturn, orb 0°00′
• Gavin Newsom: Sun square Moon, orb 0°01′
• Marion Cotillard: Saturn square Uranus, orb 0°04′

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