Ketu in Vedic Astrology — Lunar Node, Mythology & Mantra

Significations (karakatva)

Ketu, the second shadow planet, signifies detachment, spirituality, moksha (liberation), past-life karma, intuition, sudden events, injuries, occult knowledge and the paternal grandfather. It is said to act like Mars, and is generally treated as a malefic, but it is also called the moksha-karaka, the significator of liberation, and its placement in the twelfth house is traditionally seen as favourable for spiritual life. Ketu cuts away attachment to the matters of the house it occupies. Professions linked with Ketu include research, medicine, astrology, spiritual teaching and computer programming. Ketu mahadasha is the first dasha of anyone born with the Moon in Ashwini, Magha or Mula.

Astronomy: the lunar nodes and eclipses

Ketu is the south (descending) lunar node, the point where the Moon's orbit crosses the ecliptic going southwards. It is always exactly opposite Rahu and, like Rahu, moves backwards through the zodiac, taking about 18.6 years to complete a circuit and about 18 months per sign. Lunar eclipses occur when the full moon is near either node and solar eclipses when the new moon is near a node. In early Indian texts the word ketu also referred to comets and meteors, which were seen as sudden, flag-like apparitions; the identification of Ketu with the south node became standard in classical Siddhantic astronomy.

Mythology

Ketu is the headless body of the asura Svarbhanu, beheaded by Vishnu's discus after he drank the nectar of immortality during the churning of the ocean. Because the body had tasted amrita it survived as Ketu, while the head became Rahu. Ketu is depicted with a serpent's head or a smoky form, often riding a vulture, and carrying a flag (ketu means 'banner'). Some traditions describe Ketu as the leader of comets. Keezhaperumpallam in Tamil Nadu is a well-known Ketu temple, and worship of Ganesha is traditionally recommended for propitiating Ketu.