Astrological Aspects Explained: Conjunction, Sextile, Square, Trine, Opposition

An aspect is the angular distance between two planets, measured in degrees along the ecliptic. If two planets are 90° apart, they are square; 120° apart, trine. That is the whole mechanic — everything else is interpretation of what those angles mean.

Aspects are what turn a chart from a list of placements into a system. A Mars in Aries tells you how someone acts; a Mars square Saturn tells you what happens when they try.

The five major aspects

These five are the Ptolemaic aspects, named for Claudius Ptolemy, and they carry the most weight in every tradition that uses aspects at all.

The conjunction is the odd one out: it is neither soft nor hard. Its quality depends entirely on which planets are involved. Venus conjunct Jupiter and Mars conjunct Saturn are the same aspect and nothing alike.

Orbs — and why there is no agreed standard

An aspect is rarely exact. The orb is how far from exact you will still count it.

Common working orbs:

• Conjunction, opposition — 8–10°
• Square, trine — 6–8°
• Sextile — 4–6°
• Minor aspects — 1–3°
• Aspects to the Sun and Moon are usually given a wider orb than aspects between other planets

Practitioners disagree, and there is no test that settles it. Some work tight (5° for everything), some work wide (12° to the luminaries). A wider orb does not find more truth; it makes an aspect harder to falsify, because almost any two planets are within some orb of some angle. If a reading depends on an aspect at 9°, it depends on the reader's orb convention as much as on the chart.

The tighter the orb, the stronger the aspect. That much is close to universal.

Applying and separating

A distinction that most introductions skip and that changes the reading.

• Applying — the faster planet is still moving toward exactness. The aspect is building; its themes are ahead of you.
• Separating — exactness has passed and the planets are moving apart. The themes are behind you, and often better understood than felt.

In a natal chart, an applying aspect is generally read as more active than a separating one at the same orb.

Soft and hard — and the misreading

Sextiles and trines are called soft; squares and oppositions hard. The near-universal beginner error is to read that as good and bad.

What the distinction actually describes is whether the energy requires effort.

Trines work on their own. That is their strength and their weakness — a talent that never met resistance often stays undeveloped, because nothing forced the issue. People frequently cannot name their own trines; the ability is so available it does not feel like an ability.

Squares demand something. They produce friction, and friction produces action. A large share of what people actually accomplish traces to their squares. They are uncomfortable, and uncomfortable is not the same as harmful.

Oppositions require another person, or another part of the self. They are the aspect most often worked out through relationships, because the polarity is easier to see when someone else is holding one end of it.

A chart of nothing but trines is not a fortunate chart. It is frequently a passive one.

The minor aspects

Used with tighter orbs, and weighted less:

• Semi-sextile, 30° — mild friction between adjacent, unrelated signs
• Semi-square, 45° — irritation; a square's little sibling
• Quintile, 72° — associated with a particular skill or creative facility
• Sesquiquadrate, 135° — a delayed or displaced version of the semi-square
• Quincunx (inconjunct), 150° — the significant one. Two planets that cannot see each other and cannot compromise; typically read as requiring continual adjustment rather than resolution. See the quincunx in detail

Aspect patterns

Three or more aspects can lock into a recognised figure, and the figure means more than its parts:

• T-square — two planets in opposition, both square a third. A drive engine with a pressure point.
• Grand trine — three planets in mutual trine, usually in one element. Great facility, low urgency.
• Grand cross — two oppositions squaring each other. Maximum tension, maximum stamina.
• Yod — two planets sextile, both quincunx a third.

How to read an aspect in practice

1. Identify the two planets and what each governs.
2. Note the angle and the orb. Tighter is stronger.
3. Note applying or separating.
4. Note the houses involved — the aspect describes a dynamic, the houses say which areas of life it plays out in.
5. Note the signs, which colour how each planet expresses itself.
6. Check whether it is part of a pattern, which usually outweighs reading it alone.

Limitations and contested points

Orb conventions are the largest source of disagreement in aspect work, and no result settles them. Whether the minor aspects deserve weight at all is disputed — traditional astrology uses the five Ptolemaic aspects and little else, while modern practice varies widely.

Aspects to the Ascendant and Midheaven also require an accurate birth time; aspects between planets mostly do not, since planets move slowly enough that most survive an unknown hour.

And the standing caveat: this is a symbolic framework with no demonstrated predictive power. It offers a vocabulary for describing how the parts of a chart interact, which is useful whether or not the interaction is real.

Aspects also drive transits — a transiting planet matters chiefly through the aspects it makes to your natal chart — and synastry, where the same five angles are measured between two charts instead of within one.

Deep Oracle does not publish a Western chart calculator, so aspect positions need to be cast elsewhere. We do publish the placements library covering all 110 planetary placements, and the Western astrology blog.

(This is an interpretive framework — not advice.)

Related reading

• Grand Trine Pattern Explained: Gift or Trap?
• The 12 Astrological Houses Explained: The Twelve Areas of Life
• Your Big Three: Sun, Moon, and Rising Signs Explained
• Elements and Modalities: The Underlying Grid of the 12 Signs
• Chiron in Astrology: The Wounded Healer