✦ Astrology Glossary
Semi-Square
A minor aspect of 45° that creates mild tension and friction between two planets.
A semi-square is a minor aspect formed when two planets are 45° apart (with an orb of 1–2°). It represents a subtle but persistent irritation or friction that can motivate growth. Unlike the major square (90°), the semi-square is less intense but more nagging — like a small stone in your shoe rather than a boulder in your path.
How it works
In a natal chart, the semi-square is calculated by dividing the 360° circle by 8 (360/8 = 45°). It belongs to the octile series of aspects (45°, 90°, 135°). When two planets are in a semi-square, they are in signs that are 1.5 signs apart — for example, 15° Aries and 0° Gemini. The aspect is considered "hard" because it involves signs of different modalities (cardinal, fixed, mutable) and often different elements, creating a sense of discord.
In practice
In a reading, a semi-square shows up as a recurring but low-level challenge. For instance, a semi-square between Mercury and Saturn might manifest as a tendency to second-guess your own ideas or feel blocked when trying to communicate. The friction is mild enough that you might not notice it at first, but over time it builds pressure. The key is to see it as a prompt to adjust rather than a crisis. Unlike a square, which demands change, a semi-square invites fine-tuning.
For a deeper look at your chart's aspects, build your natal chart and explore the aspect list.
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Applying Aspect
An aspect where the faster planet is moving toward an exact angle with a slower planet, building energy.
Aspect
An angle between two planets in a birth chart that reveals how their energies interact.
Chart Wheel
A circular diagram representing the positions of planets, signs, and houses at a specific time and place.
Conjunction
A conjunction occurs when two planets are close together in the same zodiac sign, blending their energies into a single powerful focus.
Hard Aspect
A hard aspect is an astrological angle that creates tension, challenge, or friction between two planets.
Major Aspects
Major aspects are the five key angular relationships between planets in a birth chart that reveal core personality dynamics.