Why do we worship the moon on Karva Chauth

The month of Kartik falls during the autumn season. According to Tantra Shastra, it is customary to perform "Sammohan Karma" during this season. In Tantra Shastra, the Krishna Paksha (dark fortnight) is more important than the Shukla Paksha (bright fortnight). Karva Chauth falls on the fourth day of the Krishna Paksha (dark fortnight). On this day, the Shiva family is worshipped. Sati and Parvati are exemplars of devoted wives. Using the moon as an instrument, women worship the Shiva family, praying that just as Parvati remained Shiva's consort for many lives, she too may remain a companion to her husband. Just as Sati and Parvati's good fortune is immortal, she too may remain blessed for many lives. May she also have children as intelligent as Ganesha, as strong as Kartikeya, and who will protect the interests of the gods.

The moon is considered the lord of medicines and a symbol of the mind. The moon worship also implies a prayer for longevity and mutual love.