What is Mercury Mahadasha? Mercury Mahadasha is a very strong Dasha as Mercury is the prime ruling source of the universe. Antardasha of all planets in Mercury Mahadasha and general effects of Mercury Mahadasha. Learn about Mercury Mahadasha all planets Antardasha and the good and bad effects of the Sun, Moon, Mars, Mercury, Venus, Jupiter, Saturn, Rahu, and Ketu. Let\'s learn more about Mercury Mahadasha.