The planets are very powerful in nature and we all are under their influence. If these planets are weak or imbalanced they can make life miserable. In order to strengthen weak planets havan is performed. These Khadir sticks are offered during fire ceremony (Havan), to pacify the ill effects of Mangal or to strengthen the good effect of the planet.
Mangala is the god of Mars, the red planet. Mars is also called Angaraka ('one who is red in colour') or Bhauma ('son of Bhumi') in Sanskrit. He is the god of war and is celibate. He is considered the son of Prithvi or Bhumi, the Earth Goddess. He is the owner of the Aries and Scorpio signs, and a teacher of the occult sciences (Ruchaka Mahapurusha Yoga).He is painted red or flame colour, four-armed, carrying a trident, club, lotus and a spear. His Vahana (mount) is a ram. He presides over Mangal-var' or Tuesday
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He is of Tamas Guna in nature and represents Energetic action, confidence and ego.
There is a famous pilgrim place Mangalnath (in Ujjain,Madhya Pradesh, India). People who suffer from troubles related to Mangal Graha in their horoscope visit there on Tuesday. By worshiping & satisfying Mangal Graha, devotees get blessings & mercy of Mangal Devta. There are only two temples of Mangal devata in India, of which one is in Amalner(Maharashtra) and another in Vaitheeswaran Kovil, Tamilnadu.