Light Planet

arabic: an-naql (transfer of light, in which the lighter planet is the carrier) · latin: annacl

Definition

In traditional horary doctrine, the 'light' or 'lighter' planet is the faster-moving of two planets in a configuration — by Ptolemaic speed-order (Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn), the planet earlier in the order is the lighter — and is the body that mediates light between the heavier planet it has just separated from and the heavier planet it is about to apply to. The technical-term carries doctrinal weight in the translation-of-light and collection-of-light configurations: the lighter planet acts as the carrier or mediator, not as a primary significator in its own right within that aspect-pattern.

In Tradition

In the Arabic-Persian horary tradition formalised by Sahl ibn Bishr and inherited by the Latin West, the lighter planet's role is mediator. Sahl's translation-of-light (an-naql) is the configuration in which a lighter planet separates from a heavier one and then applies to another, bearing the first planet's nature to the second. In modern Lilly-tradition horary the lighter-planet-in-aspect is read as the party who initiates contact or makes the first move.

In Practice

Practitioners identify the lighter planet in a horary chart by checking the Ptolemaic order of speed against the two significators of a question. Where one significator is markedly faster than the other and is configured by aspect or conjunction, its motion patterns are read as carrying news, conveying the offer, or initiating the contact. In Sahl's worked translation-of-light example (Virgo rising, Moon 10° Gemini, Mercury 8° Leo, Jupiter 13° Pisces), the Moon as the lighter planet carries Mercury's nature to Jupiter. Modern Lilly-tradition horary extends the underlying mediator-doctrine to political and social party-significators: when the parties are represented by planets of different speeds, the lighter party is read as the one who reaches out or compromises first. The technical-term is procedural — it describes a positional role within a configuration, not an essential or accidental dignity.

Historical Origin

The lighter-planet doctrine is canonical Arabic-Persian horary, set out in Sahl's *Introduction* §§5.5-5.6 (translation-of-light and collection-of-light) and transmitted through John of Spain's medieval Latin translation. The Arabic technical terms are an-naql (transfer) and al-jamʿ (collection), with Latin equivalents annacl and algemmee. The doctrine enters William Lilly's *Christian Astrology* (1647) within the broader translation-of-light treatment and continues through modern horary practice (Frawley, Louis).

Further Reading