Aspectual Orbs

latin: orbis · greek: μοῖρα (moira) — degree

Definition

The zone in degrees around an exact angular separation within which an aspect between two chart-factors is considered operative. Aspects do not click on and off at exact perfection; rather, the influence builds as the faster planet applies toward exactness and fades as it separates. The orb sets the threshold for how close to the exact angle the configuration must be to count as an aspect, and the closer to exact, the stronger the configuration is read.

In Tradition

Across the Hellenistic-medieval-modern lineage the orb-of-aspect doctrine is a shared technical framework with characteristic per-planet or per-aspect values. Holden traces the canonical Hellenistic numbers to Porphyry's *Introduction* Ch 55 (possibly via Zahel): Sun 15°, Moon 12°, Saturn and Jupiter 9°, Mars 8°, Venus and Mercury 7°. The same Lilly-era tradition assigns Jupiter and Saturn 9° before and after any aspect. Martin's modern Western orb-table follows the alternative per-aspect logic: major aspects 8°, sextile 4°, minor aspects 2°.

In Practice

Practitioners assess each pairing of chart-factors and ask whether the angular separation falls within an appropriate orb of one of the recognised aspects. Two main orb-schemes are in use: the traditional per-planet scheme (each planet carries its own orb, applied symmetrically to either side of the aspect) and the modern per-aspect scheme (each aspect carries its own orb, with the major aspects given wider tolerances than the minor). The applying / separating distinction modifies the reading: applying aspects (faster planet moving toward exactness) are weighted more heavily than separating aspects of the same orb, and Martin notes 'it is perfectly acceptable to stretch the orbs a bit when an aspect is applying.' The Sun and Moon are commonly given wider orbs in both schemes. Tight orbs (≤1°) are weighted as the most active configurations in the chart, with widening orbs signalling decreasing intensity.

Historical Origin

Holden notes that orbs were not part of the original Greek horoscopic system because aspects were reckoned by sign; the doctrine emerged only when later astrologers began to track angular separation in degrees. Porphyry Ch 55 (or its Zahel source) is the earliest canonical orb-list; Lilly's *Christian Astrology* (1647) preserves the Renaissance per-planet form; Martin's *Mapping the Psyche Vol 2* documents the standard modern Western per-aspect form.

Etymology

Origin: Latin / Greek. Meaning: Orb from Latin orbis ('disk, circle'), used in classical astrology for the planet's apparent disk and by extension for the zone of effective influence; cognate with Greek μοῖρα (moira, 'degree' or 'allotment') which carries the underlying degree-reckoning sense..

Definition

In Tradition

In Practice

Historical Origin

Etymology

Further Reading