Altitude

Definition

Altitude is the angular height of a celestial body above (or below) the horizon, measured in degrees. Zero degrees sits exactly on the horizon; ninety degrees is directly overhead at the zenith. Altitude is distinct from declination (distance north or south of the celestial equator) and from ecliptic latitude (distance north or south of the ecliptic). A planet closest to the Midheaven degree by ecliptic longitude is not necessarily the highest-altitude planet — the planet with highest altitude is typically the one most closely squaring the Ascendant by primary motion, roughly ten zoidia from the rising point.

In Tradition

In the Hellenistic-through-traditional Western lineage altitude is one of the technical accidental-dignity indicators: a planet high in altitude is read as exposed, prominent, and acting from a position of visibility, in contrast to a planet of low or negative altitude (below the horizon) which is hidden or working secretly. The doctrine is preserved in modern revival traditional practice as part of the standard chart-condition assessment.

In Practice

When you assess a planet's accidental condition you check its altitude in addition to its house placement, sign-dignity, and motion. A planet near the upper meridian with high altitude is angularly prominent in the strongest sense — Crane's worked example (the Bernadette of Lourdes chart) shows Venus close to the Midheaven by longitude with altitude 27°31 north, while Mars, closer to a square with the Ascendant, has the higher altitude of 33°03 north and is therefore read as the most elevated planet despite Venus's nominal MC proximity. The distinction matters for primary directions, parans, and any technique that takes the actual diurnal geometry of the body rather than its ecliptic longitude alone.

Historical Origin

Altitude as a technical measure is part of Hellenistic spherical astronomy; the Greek term hypsos (ὕψος, 'height') is used for both the astronomical altitude and the related astrological dignity of exaltation. The doctrine is preserved through Ptolemy's *Almagest* and *Tetrabiblos*, the Arabic transmission, and the medieval Latin observational tradition (Bonatti's instruments include the quadrant for measuring altitudes). Crane's *Astrological Roots: The Hellenistic Legacy* preserves the doctrine for modern revival practice.

Etymology

Origin: Latin. Meaning: From altus ('high'); altitudo, 'height.' Used in astronomy for vertical angle above the horizon..

Further Reading

• Joseph Crane, Astrological Roots: The Hellenistic Legacy
• Claudius Ptolemy, Tetrabiblos
• Claudius Ptolemy, Almagest