Aspect

A specific angular relationship between two planets in a chart (such as 0°, 60°, 90°, 120°, or 180°), interpreted as a meaningful interaction between the two bodies.

An aspect is the geometric relationship between two points in a chart, measured as the angular distance between them along the ecliptic. The five "major" or "Ptolemaic" aspects are the conjunction (0°, two planets in the same place), the sextile (60°), the square (90°), the trine (120°), and the opposition (180°). Each is interpreted as a specific kind of energetic interaction between the two bodies involved.

Aspects are the connective tissue of a chart. A chart with isolated planets reads as a list of placements; a chart full of aspects reads as a network of interactions. The aspects describe how the planets in your chart talk to each other, support each other, or pressure each other. A Mars trine Venus is interpreted very differently from a Mars square Venus, even when the planets are in the same signs.

Conjunctions and oppositions are the strongest aspects, treated as the most active and demanding. Trines and sextiles are softer, often interpreted as supportive or natural-flowing. Squares are tense and motivating, traditionally framed as challenges that produce growth. The exact emotional flavor of each depends on the planets involved and the context of the rest of the chart.

Aspects also have an orb — the allowable margin of error around the exact angle. Two planets do not need to be exactly 90 degrees apart for the square to count; an orb of 6–8 degrees is typical for the major aspects involving the inner planets, and tighter orbs are used for transits to natal positions. ZODIA uses planet-specific orbs in its transit detection: tighter for the Moon, wider for Jupiter and Saturn.