Rāhu is the north node of the Moon — not a physical planet but a mathematical point, the ascending intersection of the Moon’s orbital path with the ecliptic. In classical Jyotiṣa, Rāhu is treated as a fully functional graha with profound influences on worldly life, karma, and the quality of consciousness. Parāśara describes Rāhu as having a body like a serpent (nāga), dark blue or smoky complexion, a fundamentally tamasic nature similar to Saturn, and belonging to the outcast (caṇḍāla) varṇa — placing it outside the conventional social order and associating it with all that lies at the margins, the boundaries, and the threshold zones of established reality.
The kārakatva of Rāhu includes: foreign countries and foreign elements, outcasts and marginalized persons, unconventional and taboo activities, sudden and unexpected events, confusion, illusion (māyā), epidemic disease, poison, smoke and fog, electricity (modern associations), technology (modern), gambling and speculation, paternal grandfather, and the principle of desire that pulls the native toward unfamiliar or transgressive experiences. In the natal chart, Rāhu’s house and sign position indicates where the native is drawn compulsively toward new experience, where past-life karma creates intensity around unfamiliar territory, and where the conventional rules seem either inapplicable or particularly constraining.
One of the foundational principles of classical Rāhu interpretation is its tendency to amplify and intensify whatever it contacts. Planets conjunct Rāhu in a natal chart tend to express with unusual intensity, unconventionality, or an obsessive quality that goes beyond ordinary planetary expression. This amplification can produce extraordinary talent and unusual achievement in the area concerned — many of the most remarkable achievers in any field have Rāhu prominently placed — but the amplification can also produce distortion, addiction, or the inability to modulate the intensity of expression toward sustainable levels.
Rāhu’s behavior in the different rāśis reflects the nature of whatever sign it occupies — unlike the traditional planets, which have fixed own-signs and dignities, Rāhu’s behavior is more chameleonic, taking on the qualities of the sign’s lord while adding its own intensifying, boundary-dissolving energy. In Venusian signs (Vṛṣabha, Tulā), Rāhu produces intensified desire for beauty and pleasure. In Saturnine signs (Makara, Kumbha), it intensifies ambition and the drive for social achievement. In the sign of the Sun (Siṃha), it can produce charismatic but unstable authority. Classical texts note that Rāhu in the upachaya houses (3, 6, 10, 11) often produces notable worldly achievement, particularly in political and commercial domains.
The Rāhu-Ketu axis always occupies opposite signs and represents the karmic axis of the horoscope — the direction of past-life accumulation (Ketu) and future-life development (Rāhu). This framework, systematized in the Uttarakālamṛta and elaborated in modern Jyotiṣa through commentators like B.V. Raman, holds that Rāhu’s house and sign indicate the direction of greatest karmic growth and the area where the native must develop new competencies that were absent or underdeveloped in previous lives. The Rāhu Mahādaśā spans 18 years in the Viṃśottarī scheme — a period that typically brings intensity, rapid change, unusual opportunities, and the native’s most significant engagement with foreign or unconventional elements of life.
In Praśna Jyotiṣa, Rāhu’s position in the chart is carefully examined for questions involving foreign matters, unconventional situations, sudden changes, poison or infection, deception or concealment, and any question where the circumstances are genuinely unusual or where the querent feels overwhelmed by factors outside their control. Rāhu’s conjunction with the Lagna lord or the Moon in a Praśna chart is considered a complex indicator — it can bring unexpected developments that alter the expected course of events, and the classical commentators counsel extra care in interpretation when Rāhu is prominently placed in a Praśna lagna.