It is said that once Moon God Chandra, who was very handsome and proud of his looks, tried to make fun of Lord Ganesha by making sarcastic remarks. Chandra commented upon the looks of Lord Ganesha saying Ganesha has got big belly and elephant head.
So, Lord Ganesha cursed Chandra saying that no one will worship the moon and whoever looks at the moon will face false allegations and suffer bad name even when innocent. Hearing this punishment, Chandra got shattered and devastated; his rudeness and arrogance vanished in a jiffy. Chandra, along with other Gods, started worshipping Lord Ganesha to apologise and appease him again. At last, Lord Ganesha was pleased and decided to relieve Chandra from the curse but with a clause. He said human beings can look at the moon on any day except that day of ‘Bhadrapada Chaturthi’. He said anyone who sees the moon on Bhadrapada Chaturthi will have to face false allegations. Since that day, ‘Bhadrapada Chaturthi’ is celebrated as Ganesh Chaturthi.