Planet Mercury in Vedic Astrology - clickastro.com Mercury has a Mahadasha period of 17 years. Mercury is in an exalted state in Virgo at 15 degrees and is the only planet to be exalted in its own house. It is debilitated in Pisces at 15 degrees. Mercury finds directional strength in the 1st house of astrology. Mercury's day is Wednesday, and it is associated with the green color.