What is
Mercury retrograde?
Mercury retrograde is the three weeks, about three times a year, when Mercury appears to move backward against the stars. The next one runs from February 9, 2027 at 17:36 UTC to March 3, 2027 at 12:32 UTC.
The short answer
Mercury retrograde is a period of about three weeks when Mercury, seen from Earth, appears to drift backward against the background stars. It happens three times most years, occasionally four. Mercury never actually reverses: the effect comes from Earth and Mercury moving at different speeds on different orbits. The next retrograde runs from February 9, 2027 at 17:36 UTC to March 3, 2027 at 12:32 UTC, 22 days in Pisces and Aquarius. Is Mercury retrograde today?
Why a planet looks like it moves backward
Mercury orbits the Sun in 88 days, Earth in 365. Both move in the same direction, but Mercury moves faster and on a smaller circle. Roughly every 116 days Mercury laps Earth on the inside. For a few weeks around that moment, Mercury's position against the fixed stars, as plotted night after night from Earth, slows, stops, and runs backward before turning forward again. The same thing happens when a faster car passes you on a motorway: for a moment, against the distant landscape, it seems to slide backward.
The moment Mercury passes between Earth and the Sun is called the inferior conjunction. In the astrological tradition the exact alignment is called cazimi. It always falls in the middle of the retrograde. The next cazimi is February 18, 2027 at 16:39 UTC.
The five moments of a cycle
Each Mercury retrograde cycle has five moments that can be timed to the minute:
- Pre-shadow begins: Mercury, still moving forward, reaches the degree where it will later turn direct. For the coming cycle: January 25, 2027 at 18:58 UTC.
- Station retrograde: the minute Mercury's apparent motion along the ecliptic stops and turns backward. February 9, 2027 at 17:36 UTC.
- Cazimi: the inferior conjunction with the Sun, in the middle of the retrograde. February 18, 2027 at 16:39 UTC.
- Station direct: the minute Mercury's apparent motion turns forward again. March 3, 2027 at 12:32 UTC.
- Post-shadow ends: Mercury passes the degree where it had stationed retrograde. March 23, 2027 at 14:58 UTC.
Only the stretch between the two stations is the retrograde proper. The shadow periods on either side are explained in the shadow period guide.
How often and how long
Mercury's synodic period, the time between two inferior conjunctions, averages 116 days, so there are usually three retrogrades a year and every few years four. Each lasts 19 to 24 days from station to station. The length varies because Mercury's orbit is markedly elliptical: near perihelion it moves faster and the retrograde is shorter. Across a year the three retrogrades fall in signs of the same element, and over the years they drift slowly backward through the zodiac. The cycle after the next one runs from June 10, 2027 at 18:15 UTC to July 4, 2027 at 19:39 UTC. Every cycle from 1900 to 2050 is listed on the birthday checker; the years 2026 to 2030 have their own pages.
Can you see it?
Yes, though not easily. Before the retrograde Mercury is an evening object low in the west after sunset; after the cazimi it reappears as a morning object low in the east before dawn. Around the stations it hangs near the same spot for several evenings or mornings, which is the easiest time to notice it. At the cazimi itself it is lost in the Sun's glare, except during the rare transits when it crosses the solar disc.
Astronomy, not a forecast
Everything on this page is geometry: positions computed from the JPL DE421 planetary ephemeris, the same model used for spacecraft navigation, rounded to the minute in UTC. Cazimi does not read birth charts or predict events. What people choose to do during the retrograde is a tradition, described in the practical guide; when it happens is a fact, and that is what this site tracks. How the moments are timed.
Questions
Does Mercury really move backward?
No. Retrograde is apparent motion caused by Earth overtaking Mercury on the inside track; Mercury's own orbit never reverses. The next apparent reversal begins February 9, 2027 at 17:36 UTC.
How long does Mercury retrograde last?
Between 19 and 24 days from station to station; the cycle starting February 9, 2027 at 17:36 UTC lasts 22 days, until March 3, 2027 at 12:32 UTC.
How many times a year is Mercury retrograde?
Three times most years, four in some, because the Sun-Mercury synodic period averages 116 days; after the cycle ending March 3, 2027 at 12:32 UTC, the next begins June 10, 2027 at 18:15 UTC.