There is a close link between Lord Hanuman and astrology. Worshipping Lord Hanuman, all defects of planets are prevented.
Lord Shani is the son of God Sun. To satisfy his ego, Lord Shani had forced Lord Hanuman to fight with him. Lord Hnauman had therefore tied Lord Shani in his tail and had taken an entire circle of the solar system. Lord Shani’s entire body had started bleedingand he requested Lord Hanuman to let him go. Lord Hanuman agreed but on a condition that Lord Shani will not trouble any of his devotees. Later, Lord Shani cured his body by applying oil.