Kethu represents karmic collections both spirituality and supernatural influences according to In Hindu astrology. Kethu is associated with the Meena Avatar (Fish Incarnation) of Vishnu. Ketu causes material loss in order to force more spiritual outlook in the person. Ketu is indicator of intelligence, non-attachment, fantasy, penetrating insight and psychic abilities. Ketu is believed to bring prosperity to the family. He grants good health and wealth to his devotees. Ketu is the lord of three nakshatras that are Ashvini, Magha and Mula.

According to the mythology, an asura’s head was cut off by God Vishnu. This result the asura’s head and body joined with a snake to form ‘Ketu’ and ‘Ragu’. Ketu represents the body without a head, and Ragu, represents the head without a body. According to the accounts in Hindu mythology, Ketu belongs to Jaimini Gotra and Rahu belongs to Paiteenasa gotra. It is to be understood that both ketu and Ragu are completely different entities with distinct characteristics. Ketu is generally referred to as a “shadow” planet. It is believed that Ketu to have a marvellous impact on human lives. Ketu is often depicted with a gem on his head signifying a mystery light.

The Temple dedicated to the Kethu is Kethu Sthalam is in the village of Keezhaperumpallam. This Sthalam is just 2 kilometres away from Poompuhar and comes within the range of Nagapattinam district. The presiding deity is Ketu. But still, the main idol is “Naganatha Swamy” or Shiva. Other name for this sthalam is Naganatha Swamy Temple.