Aspect geometry and orb conventions
How exact angular separations become named aspects only after a declared angle list and maximum-orb policy are applied.
Calculation contract · released 2026-08-18
Definition
An aspect is a classification of the shortest angular separation between two chart points relative to a selected exact angle and allowable orb.
Calculation procedure
Compute both longitudes in the same frame, obtain shortest separation, compare with each exact angle, and include an aspect only when absolute deviation is within its stated maximum orb.
Required inputs
- Two unrounded longitudes in one frame
- Exact aspect-angle set
- Per-aspect maximum orbs
Maha convention
Maha natal output uses conjunction 8°, sextile 4°, square 6°, trine 6°, and opposition 8°, sorted by smallest orb.
Uncertainty and edge cases
Orb limits are interpretive conventions, not astronomical constants; another pack can classify the same geometry differently.
What this does not establish
An aspect’s presence does not establish its traditional meaning or predictive value.
Authoritative references
These sources establish the calculation vocabulary, data product, or transformation convention. They do not establish astrological interpretation.
- Horizons System Manual
NASA/JPL Solar System Dynamics · 4.98d (2025-11-21)
Solar-system object identifiers, observing centers, time inputs, reference frames, corrections, output quantities, and stated ephemeris limitations.
Boundary: Horizons output is authoritative only with the complete query contract preserved; transformed or rounded values require their own provenance record.