Ketu

Ketu is one of the nine celestial bodies (Navagraha) in Hindu astrology, representing the descending lunar node. Unlike physical planets, Ketu is a shadow planet (chhaya graha) with no tangible form, yet it exerts profound karmic influence. Its origin is traced to the Puranic myth of the churning of the ocean (Samudra Manthana), as described in the Mahabharata (Adi Parva) and the Bhagavata Purana (Canto 8). According to these texts, the asura Svarbhanu disguised himself among the devas to drink the nectar of immortality. The sun and moon alerted Vishnu, who severed Svarbhanu's head with his discus.

The head became Rahu (the ascending node), while the body became Ketu (the descending node). This myth explains Ketu's iconography as a headless torso or a serpentine tail. In the Rigveda (1.32), Ketu is mentioned as a comet or banner of smoke (dhūmaketu), symbolizing sudden calamities or transformations. Iconographically, Ketu is depicted with a dark complexion, riding a vulture or a dark chariot, holding a flag or mace, and sometimes shown with a serpent's tail. Symbolically, Ketu represents detachment, spiritual liberation (moksha), and the culmination of karmic patterns.

In Hindu cosmology, Ketu governs the south-west direction and is associated with the element of ether. Regional worship traditions include Ketu Puja performed during eclipses or to mitigate malefic effects, especially in South India where temples like the Navagraha temples in Tamil Nadu house Ketu shrines. The Skanda Purana and the Jyotisha Shastra detail Ketu's influence on human destiny, linking it to sudden upheavals, mystical insights, and the dissolution of ego. Ketu is also identified with comets (dhūmaketu) and is considered a granter of moksha when propitiated correctly. Its role in Hindu cosmology is to sever attachments and propel souls toward liberation, acting as a karmic accountant that balances past deeds.

The Sanskrit word 'Ketu' (केतु) derives from the root '√cit' meaning 'to perceive' or 'to appear,' and originally signified a 'banner,' 'sign,' or 'comet'—something that is 'known from a distance' (kīyate iti ketuḥ). In the Rigveda (1.32.6), ketu appears as 'dhūmaketu' (smoke-bannered), referring to a comet or meteor.

The term later became the proper name for the descending lunar node. Regional variants include 'Kethu' in Tamil and 'Ketu' in Telugu.

The Mahabharata (Adi Parva 19) and Puranas (e.g., Bhagavata Purana 8.9.25-28) narrate that Ketu is the headless torso of the asura Svarbhanu, beheaded by Vishnu, thus linking the name to the concept of a 'severed body.' Dowson's 1879 Classical Dictionary notes alternate names: A-kacha ('hairless'), Aslesha-bhava ('cut off'), and Murcha ('bald'). The word also appears in astronomical texts like the Surya Siddhanta (1.13) to denote the descending node.

Ketu first appears in the Rigveda (1.32.6) as 'dhūmaketu' (smoke-bannered), describing a comet or meteor associated with Indra's slaying of Vritra. The term is used in a general sense for 'banner' or 'sign' in early Vedic literature.

The personification of Ketu as a deity emerges in the Puranic era, particularly in the Mahabharata (Adi Parva 19) and the Bhagavata Purana (Canto 8, Chapter 9), where the myth of Svarbhanu's beheading is detailed. In these texts, Ketu is the body of the asura who drank the nectar of immortality, cut off by Vishnu's discus.

The Skanda Purana (Kashi Khanda 37) and the Jyotisha Shastra (e.g., Brihat Parashara Hora Shastra) elevate Ketu to a Navagraha, a shadow planet with karmic influence. The Surya Siddhanta (1.13) treats Ketu astronomically as the descending node.

Over time, Ketu's role shifted from a comet to a malefic planet in astrology, with sectarian emphasis in Shaiva and Shakta traditions as a granter of moksha. The Agni Purana (Chapter 51) describes Ketu's iconography and worship, solidifying his place in Hindu cosmology.

Ketu is typically depicted as a dark-complexioned, headless torso, often with a serpent's tail, symbolizing his origin as the severed body of Svarbhanu. He has two arms, one holding a mace (gadā) and the other in varadamudrā (boon-granting gesture).

His vahana (vehicle) is a vulture or a dark chariot drawn by pigeons. In South Indian bronze iconography, Ketu is shown with a serene expression despite his headless form, emphasizing his role as a spiritual liberator.

North Indian miniature paintings often portray him as a dark figure riding a vulture, with a flag or banner (ketu) in hand. The Dhyana-shloka from the Agni Purana (Chapter 51) describes Ketu as having a dark complexion, wearing ornaments, and holding a mace.

Regional variations include the depiction of Ketu as a serpent's tail in Tamil Nadu's Navagraha temples, such as the Suryanar Kovil. The Shilpa-shastra texts (e.g., Manasara) prescribe that Ketu should be shown with a serpent's lower body, emphasizing his chthonic and karmic nature.

In Advaita Vedanta, Ketu represents the illusory nature of the individual self (jiva) and the severance of attachment to the body, leading to moksha. The headless form symbolizes the transcendence of ego and worldly senses. In Vishishtadvaita, Ketu is a subordinate deity serving Vishnu, embodying the karmic consequences that lead souls toward surrender (prapatti).

Dvaita philosophy views Ketu as a distinct entity with a role in cosmic justice, punishing the wicked and rewarding the virtuous. In Shakta and Tantric traditions, Ketu is associated with the goddess Chinnamasta (the severed-headed goddess), representing self-sacrifice and spiritual awakening. The Brihat Parashara Hora Shastra (Chapter 3) describes Ketu as a karaka (indicator) of moksha, sannyasa, and psychic abilities.

In Jyotisha, Ketu is considered both malefic and benefic: it causes material loss but fosters detachment and spiritual growth. The Skanda Purana (Kashi Khanda) emphasizes Ketu's role in severing karmic bonds, aligning with the concept of prarabdha karma. Commentators like Parashara and Varahamihira discuss Ketu's influence on human destiny, linking it to sudden transformations and liberation.

Ketu appears in Bharatanatyam and Odissi dance repertoires through the Navagraha nritya, where dancers depict the nine planets with specific mudras and expressions. In Carnatic music, compositions like the 'Navagraha Kritis' by Muthuswami Dikshitar include a kriti for Ketu (e.g., 'Mahasuram Ketum' in Raga Shankarabharanam).

Hindustani classical music also features dhrupads and khyals dedicated to Ketu. In painting, Ketu is depicted in Tanjore and Pahari miniatures as a dark, headless figure riding a vulture.

Folk traditions in South India include Ketu Puja during eclipses and the 'Ketu Dosh' rituals to mitigate malefic effects. In Bali, Ketu is incorporated into the Hindu calendar system (Pawukon) and is invoked in temple ceremonies.

In Cambodia and Thailand, Ketu appears in astrological texts and is associated with the lunar node. The Navagraha temples in Tamil Nadu, such as the one in Kumbakonam, house a separate shrine for Ketu, where devotees offer prayers for spiritual liberation and relief from karmic afflictions.