The Observatory Desk · Explained twice
Mercury retrograde, explained twice.
Mercury retrograde is the stretch of about three weeks, three times in most years, when the planet Mercury appears to stop and drift backwards against the stars. In astrology it is a famous season: Mercury is the planet of messages and travel, and its backward phase is traditionally read as a time of confusion and delays. In astronomy it is a trick of perspective: Mercury, racing round the Sun on the inside track, overtakes Earth, and from our moving viewpoint its direction seems to reverse. It never actually turns round. This page tells it both ways, gives the 2026 and 2027 dates from NASA's ephemeris, and lets you watch the loop happen.
Where Mercury is nowAs of October 2026, the next Mercury retrograde runs from 24 October to 13 November 2026, all of it in the sign of Scorpio. The dates for 2026 and 2027 are in the table below.
Plate · The Short Answer, Twice
Two ways to say backwards.
Astronomy · measured
Mercury only appears to go backwards. It laps the Sun every 88 days; Earth takes a year. About every 116 days Mercury catches up with Earth and passes between us and the Sun. For roughly three weeks around that moment it is close to us and crossing our line of sight in the direction that carries it westward against the stars, so its usual eastward drift seems to stop, reverse, stop again and resume. Its orbit never changes direction.
Astrology · read
Mercury's backward phase is read as a season of mix-ups. In Western astrology Mercury rules communication of every kind, and with it contracts, travel and the post. Its retrograde periods are traditionally linked with confusion, delays and disruptions in those areas, so astrological guides often frame them as a time for revisiting rather than starting. The Astrarium describes that reading as a tradition — not a forecast, and not advice.
Plate · The Live Model
Watch the loop.
Left: the Sun, Mercury and Earth seen from far above the solar system, with the line from Earth to Mercury — the direction we look to see it. Right: where that line points among the stars, which is all an observer on Earth can see. Press play, or drag the slider through the weeks, and watch the line on the left swing back while the dot on the right walks backwards.
The live model needs JavaScript, which is switched off here. The same motion is drawn as a still diagram under "Why it happens" below, and every date on this page is in the table.
From aboveSun · Mercury · Earth
From EarthMercury against the stars · east is left
Positions are calculated in your browser from NASA JPL's published orbital elements (details under How this is calculated). The background stars are decorative; the sign boundaries and every planet position are real.
Plate · The Dates
Mercury retrograde in 2026 and 2027.
The moment Mercury stands still and turns backwards is called its station retrograde; the moment it turns forwards again is its station direct. Times are in UTC, from NASA JPL's Horizons ephemeris, and positions are in the tropical zodiac that Western astrology uses.
| Period | Turns backwards | Turns forwards | Length | Passes between Earth and Sun | Shadow (astrological term)* |
|---|---|---|---|---|---|
| 2026 | |||||
| 26 Feb – 20 Mar 2026 | 26 Feb · 06:4822°34′ Pisces | 20 Mar · 19:328°29′ Pisces | 22½ days | 7 Mar | 11 Feb – 9 Apr |
| 29 Jun – 23 Jul 2026 | 29 Jun · 17:3626°15′ Cancer | 23 Jul · 22:5816°19′ Cancer | 24 days | 13 Jul | 13 Jun – 7 Aug |
| 24 Oct – 13 Nov 2026 | 24 Oct · 07:1220°59′ Scorpio | 13 Nov · 15:545°02′ Scorpio | 20½ days | 4 Nov | 4 Oct – 30 Nov |
| 2027 | |||||
| 9 Feb – 3 Mar 2027 | 9 Feb · 17:365°59′ Pisces | 3 Mar · 12:3220°55′ Aquarius | 22 days | 18 Feb | 25 Jan – 23 Mar |
| 10 Jun – 4 Jul 2027 | 10 Jun · 18:146°22′ Cancer | 4 Jul · 19:3827°28′ Gemini | 24 days | 23 Jun | 26 May – 19 Jul |
| 7 Oct – 28 Oct 2027 | 7 Oct · 14:364°56′ Scorpio | 28 Oct · 14:1019°19′ Libra | 21 days | 19 Oct | 17 Sep – 13 Nov |
Why some calendars give a different day. A station is a single moment, so its calendar date depends on where you are. Mercury turns forwards at 22:58 UTC on 23 July 2026, which is already 24 July in most of Asia and Australia; calendars set to US Eastern time put every 2026 and 2027 date on the same day as this table. A station is also a slow, gentle turn rather than a sharp one, so tables that work from different ephemerides can differ by a few minutes.
*Shadow is an astrological term, not an astronomical one: the weeks before and after a retrograde when Mercury crosses the same stretch of the zodiac it is about to retrace, or has just retraced. The shadow dates above are our own calculation from the same JPL data: from the day Mercury first reaches the degree where it will later turn forwards, to the day it gets back to the degree where it turned backwards.
Checked twice. The station times come from NASA JPL's Horizons system (Mercury's apparent ecliptic longitude seen from Earth's centre, sampled every two minutes). The days match the 2026–2027 lists published by The Old Farmer's Almanac and the Farmers' Almanac, and the dates Mercury passes between Earth and the Sun are from Fred Espenak's 2026 and 2027 sky event almanacs. The model above, which uses much simpler formulas, puts all twelve stations within a quarter of an hour (12 minutes at most) of the Horizons times.
Plate · The Geometry
Why it happens.
Every planet drifts slowly eastward through the zodiac most of the time, because it is going round the Sun in the same direction as Earth. What we see, though, is not the planet's motion alone; it is the planet's motion as seen from a platform that is itself moving, and sometimes the two combine to make the planet look as though it is going backwards.
For Mercury the key moment is inferior conjunction, when it passes between Earth and the Sun. Mercury is the fastest planet, so it is Mercury that catches up with Earth, not the other way round. Around that moment Mercury is at its closest to us, and its sideways movement across our line of sight carries it westward against the background stars, against its usual direction. That is why each retrograde period in the table brackets one of these passes.
- Approach. Mercury is swinging round its orbit towards Earth. Seen from Earth it moves eastward through the zodiac and appears in the evening sky after sunset; as its motion relative to us turns more towards us and less across our line of sight, that eastward drift slows.
- Station retrograde. For a moment Mercury's sideways motion relative to us drops to zero, and it stands still against the stars.
- Overtaking. Mercury passes between Earth and the Sun, moving faster than us on the inside track. Its sideways motion now carries it westward: it is retrograde. It is lost in the Sun's glare here, so the backward walk is mostly invisible to the eye.
- Station direct. As Mercury pulls ahead and swings away, the backward drift slows to a stop.
- After. Mercury moves eastward again and climbs into the morning sky before sunrise. By the last date it is back where it stood still at point 3, the end of what astrologers call the shadow.
Mercury's path also tilts a little above and below the Sun's path, because its orbit is inclined by about 7° to Earth's. Add that to the backward walk and the track on the sky becomes the loop or zigzag you see in the model. Every planet does this. Mars, Jupiter and the other outer planets go retrograde around the time Earth overtakes them; Venus, like Mercury, does it around the time it passes between Earth and the Sun. Ancient astronomers explained these loops with circles riding on circles, or epicycles; the Sun-centred picture explains them as perspective.
You can check the current state of every planet on Today's Sky, which marks any planet that is retrograde on the date you choose.
Plate · The Tradition
What astrologers mean.
In Western astrology each planet governs a set of themes. Mercury, named after the swiftest of the Roman gods, governs communication — speaking, writing, reading and listening — and the things that carry messages and people: contracts and negotiations, travel, cars, shipping and the post. When the planet appears to go backwards, the tradition holds that its themes are turned round too. The Old Farmer's Almanac sums up the common view: retrograde periods are traditionally linked to confusion, delays, and disruptions in communication, travel, and decision-making
.
In practice, astrological guides describe a retrograde in re- words: reviewing, revisiting, reanalysing. The Old Farmer's Almanac, for one, frames it as a time to revisit old projects rather than start new ones. Many also watch the shadow weeks either side, when Mercury is crossing the same degrees it is about to retrace or has just retraced. Astrological calendars also note the sign each retrograde falls in — Scorpio for the one beginning on 24 October 2026 — and read the period through that sign's themes; the Planets and Scorpio pages describe how the tradition reads each.
Where the idea comes from. According to a history of the belief in Mental Floss, Mercury retrograde was noted in British agricultural almanacs in the mid-18th century; Victorian astrology publications linked it with heavy rain; and by the 1970s, when horoscopes were a newspaper fixture, it was a regular feature.
What science says. The motion is real and measurable; the meanings are not something astronomy can measure. Asked about Mercury retrograde by NBC News in 2017, a curator of astrophysics at the American Museum of Natural History said there was no scientific evidence that any planet affects life on Earth. The Astrarium presents the astrological reading as what it is: a long-standing symbolic tradition and a lens for reflection, never a prediction and never advice about travel, money, health, relationships or any decision.
Plate · Straight Answers
Quick answers.
Is Mercury actually moving backwards?
No. Mercury always travels round the Sun in the same direction. It only appears to move backwards against the stars, for about three weeks around the time it overtakes Earth and passes between us and the Sun. The backward motion is an effect of watching from a planet that is itself moving.
How often does Mercury go retrograde?
About every 116 days, which is how long Mercury takes to catch up with Earth again, so three times in most years. Because 116 days does not divide evenly into a year, a fourth retrograde sometimes begins in the same calendar year: 2022 had four, and the next year with four is 2029.
How long does Mercury retrograde last?
Between about 20 and 24 days, usually described as three weeks. The three periods in 2026 last 22½, 24 and 20½ days. Astrologers who also count the shadow weeks either side treat the whole episode as lasting about two months.
When is the next Mercury retrograde?
Mercury turns backwards on 24 October 2026 at 07:12 UTC, at 20°59′ Scorpio, and turns forwards again on 13 November 2026 at 15:54 UTC, at 5°02′ Scorpio. The retrogrades after that begin on 9 February, 10 June and 7 October 2027.
What does Mercury retrograde mean in astrology?
In Western astrology Mercury governs communication, contracts, travel and the post, and its retrograde periods are traditionally linked with confusion, delays and disruption in those areas, so astrological guides frame them as a time to review and revisit rather than begin. The Astrarium presents this as a symbolic tradition, not a forecast.
Why do websites give slightly different dates?
Mostly time zones. Each station is a single moment, so it can fall on different calendar days in different places: Mercury turns forwards at 22:58 UTC on 23 July 2026, which is already 24 July in most of Asia and Australia. Some calendars also add the shadow weeks, and tables built from different ephemerides can differ by a few minutes.
Can you see Mercury retrograde in the sky?
Mostly not. Mercury goes retrograde around the time it passes between Earth and the Sun, so it sits close to the Sun in the sky and is lost in its glare. You can watch the approach: in 2026 Mercury is at its greatest distance east of the Sun, in the evening sky, on 12 October, twelve days before its retrograde begins, and it passes between Earth and the Sun on 4 November.
Is Mercury closer to Earth when it is retrograde?
Yes. The middle of each retrograde is the moment Mercury passes between Earth and the Sun, when it is at its nearest to us in its 116-day cycle. On 4 November 2026 it is about 101 million kilometres away; on the far side of the Sun it is roughly twice as far.
Do other planets go retrograde?
Yes, all of them. Mars, Jupiter, Saturn and the planets beyond go retrograde around the time Earth overtakes them on its faster inside track; Venus, like Mercury, does so around the time it overtakes Earth. Today's Sky shows which planets are retrograde on any date.
Plate · The Method
How this is calculated.
The live model runs entirely in your browser; nothing is looked up or sent anywhere. It uses the same small sky engine as Today's Sky and the Orrery:
- Orbits. Mercury's and Earth's positions come from the orbital elements in NASA JPL's "Approximate Positions of the Planets" (E. M. Standish, Table 1, valid 1800–2050), solved with Kepler's equation. JPL gives Mercury's heliocentric longitude from these elements as accurate to about 15 arcseconds over that range.
- The view from Earth. Mercury's direction is taken from Earth's position, corrected for the time its light takes to reach us and for the slow drift of the equinox since the year 2000, which gives its tropical zodiac position. A day counts as retrograde when that position is decreasing.
- The view from above is drawn in the fixed year-2000 frame of the orbital elements, which differs from the zodiac of 2026 by less than half a degree.
- The dates in the table are not the model's: they come from JPL Horizons, NASA's precision ephemeris, and agree with the published almanacs named above. The shadow dates are our calculation from the Horizons data.
Sources for the rest of the page: Mercury's 88-day orbit is from NASA Science; the 116-day cycle, the 20 to 24-day length of each retrograde, its link to inferior conjunction and the epicycle history are summarised in Wikipedia's "Apparent retrograde motion"; the explanation that Mercury and Venus go retrograde because they overtake Earth is also given by Astronomy magazine, and NASA's StarChild sets out the general rule that the backward motion is only apparent, seen when a faster planet passes a slower one; the astrological meanings and the definition of the shadow are from The Old Farmer's Almanac (Celeste Longacre).