Mercury is in retrograde until Jan. 2. But what exactly does that mean? When a planet is in retrograde it appears move in the opposite direction of other planets. Since Mercury completes its orbit in about 88 days, we typically experience three to four Mercury retrogrades each year. According to astrologers, Mercury rules the mind and communication as well as travel, commerce and technology. That's why Mercury can be blamed for travel delays, technology problems and people from your past coming back into the picture, they say. Tap the link in our bio read more.