Sage Astika is son of Manasa(devi)sister of the snake king vasuki,And her husband is Jaratkaru.According to puranik story Manasa went to kailash to be with her guru Shiva and the unborn child listen to Shiva along with her.She gave birth to a boy whome she named Astika and shiva gave many gems as a gift to brahamins.He also taught the boy the veda Sage Astika jan eminent learned youth, Scholar and a holy man ,also a close friend of Janamejaya, minister and a philosopher comes to know of Janamajaya's act and stops him.Astika muni whose name mean Believer; theist; God-revering person.Brahma, the Creator, had ordained that Sage Astika, the savior of the snakes, was to be born in theYayavar race of Brahmins to a powerful sage named Jaratkaru.The great sage Chyavan, the son of sage Bhrigu, tutored Astika Muni.He grew up to be an illustrious ascetic, well versed in the scriptures, fair in his dealings and respected by his peers.
The sons of Kadru watched Astika grow from strength to strength and were a relieved lot, at least those who had decided to forsake evil. The Mahabharata tells the story of Manasa's marriage Sage Jagatkru practised severe austerities and had decided to abstain from marriage. Once he came across a group of men hanging from a tree upside down. These men were his ancestors, who were doomed to misery as their children had not performed their last rites. So they advised Jagatkru to marry and have a son who could free them of those miseries by performing the ceremonies.
Vasuki offered his sister Manasa's hand to Jagatkru. On marriage, Manasa mothered a son called Astika.Sage Astika was the son born of Jaratkaru the muni and his wife with the same name, Jaratkaru(manasa)the snake ( daughter of Vasuki the king snake). According to Mahabharat Once Parikshita went hunting in the forest. .Parikshita entered into a sage Shringi's hut as he was thirsty. He found the sage in deep meditation. He bowed to him several times but as their was no response he took a dead snake and threw it around the sage's neck. Later when the sage's son heard of this incident and cursed the king to die of a snake bite on the 7th day.On hearing this, the king forswore the throne for his son Janamejaya and spent his last 7 days listening to the discourses of Sage Sukadeva on BhagavataAs prophesied, the snake king Takshaka bit Parikshita, who left his mortal remains behind and attained salvation.Other thesis say that Kali had entered the gold and thus creating man's desire for gold. Parikshit had gone hunting into the forest. He stops at one point and gets into the lake for a bath. He removes his crown and keeps it on the bank of river. Takshaka, a naga king sees the golden crown and desires to get it. He steals the crown, but he was got by Parikshita guards. Parikshita jails him. On his release Takshaka avenges Parikshit.astik maharaj's temple is situated in bebar(25 km from mainpuri). devotees used to come from far places to astik maharaj's temple.