Rahu

During the Samudra Manthan, as the assembled Devas and Asuras finally produced amrita, the demon Svarbhanu disguised himself among the gods to drink from it. Surya and Chandra recognized the impostor and alerted Vishnu, who severed the demon's head with his discus before the nectar could pass fully down his throat — but by then, immortality had already taken hold in the head. That head became Rahu: alive, eternally unsatisfied, and traditionally said to pursue Sun and Moon across the sky in retaliation, an image classical texts use to explain solar and lunar eclipses.

Rahu and Ketu are not physical bodies but the two points where the Moon's orbital path crosses the ecliptic — the lunar nodes. That a mathematical point rather than a planet is treated as having significant astrological weight is itself the point classical Jyotish makes about Rahu: influence and reality are not the same thing, and Rahu's domain is precisely the gap between them — illusion, Maya, that nonetheless shapes real outcomes.

As karaka of foreign elements, unconventional ambition, and obsession, Rahu is traditionally read as governing whatever a chart pursues past the point of ordinary satisfaction — a reading modern commentators frequently extend to technology, migration, and any field defined by crossing established boundaries. Its house and sign placement are read as showing where the native feels a persistent, hard-to-name incompleteness, and its roughly 18.6-year cycle is tracked in predictive work for periods of sudden, often disorienting change.

The Rahu–Ketu axis is read as a single karmic line running through a chart: Rahu marking unfamiliar territory the native is being pulled toward, Ketu marking familiar ground being released. Classical predictive astrology treats neither node as complete without the other — growth is described as the movement from Ketu's comfort toward Rahu's challenge, not the pursuit of Rahu alone.

In medical astrology Rahu is associated with conditions that resist straightforward diagnosis — its shadow, unlike Saturn's, does not announce itself clearly. Remedies traditionally include wearing hessonite and observing mantra practice during eclipse periods, both aimed at the same underlying goal: channeling Rahu's restless, acquisitive energy toward a genuine and worthwhile object rather than an endless, undirected pursuit.