[2][3][4] Personified as a deity, Rahu and Ketu are considered to be the two halves of the immortal asura (demon) Svarbhanu, who was beheaded by the god Vishnu.

This coincides with the precessional orbit of moon or the ~18-year rotational cycle of the lunar ascending and descending nodes on the earth's ecliptic plane.

Astronomically, Rahu and Ketu denote the points of intersection of the paths of Surya which is the Sun and Chandra which is the Moon as they move on the celestial sphere, and do not correspond to a physical planet.

Ketu is a karaka or indicator of intelligence, wisdom, non-attachment, fantasy, penetrating insight, derangement, and psychic abilities.

Ketu is believed to bring prosperity to the devotee's family, and removes the effects of snakebite and illness arising out of poisons.

Ketu is considered responsible for moksha, sannyasa, self-realization, gnana, a wavering nature, restlessness, the endocrine system and slender physique.