The last Mercury Retrograde Period of 2016 begins on Dec 19 and continues until Jan 7. Mercury is Retrograde in Sagittarius, and simultaneously in a yoga with Jupiter in Virgo. The result will be a conflict between Facts and Beliefs, along with the usual Mercury Rx problems. Analysis for Each Rising Sign Chart. Also: Uranus is exactly opposite Jupiter, and the Winter Solstice is on Dec 21.