Navagraha:

A prehistoric artist's conceptualization of the NinePlanets. (Sun,Moon,Angaraha,Budha, Guru,Sukra,Sani,Rahu,Kethu) The days of the week are named after them starting from Surya(Sun) for Sunday, Chandra(Moon) for Monday, Angaraha(Mars) for Tuesday, Budha(Mercury) for Wednesday, Guru(Jupiter) for Thrusday, Sukra(Venus) for Friday and Sani(Saturn) for Saturday. In Hindu Mythology the planets are considered as having a great inescapable influence on every individual's life. For example Sani, when it reaches certain position in space in relation to other planets, persons falling within its malevolent influence are supposed to suffer all kinds of difficulties for seven and a half years.  Raghu and Ketu are called shadow planets. One and half hours in a day is attributed to be influenced by Raghu which is called Raghu kalam.  During this period Indians never perform any auspicious event.

Each planet has a favorite color, grain, flower and metal. Devotees offer these during poojas to appease a malevolent planet which they call Graha Shanti.