Retrograde

Meaning

Seen from the Earth, each planet from Mercury outwards sometimes slows down, stands still and moves backwards through the zodiac for a few weeks or months, then turns and goes forward again. Nothing turns round in space: the backward stretch is how a planet looks from a moving Earth, as a slower car seems to drift backwards when you overtake it. The Sun and the Moon are never retrograde.

Astrology reads a retrograde planet as turned inward. Its themes are revisited, reviewed or lived more privately rather than pushed outward, and what it touches tends to come round more than once. Mercury’s retrogrades are the best known: by the popular reading, a time to reread, mend and check rather than to launch, though nothing in them foretells a failure.

In a birth chart, a planet that was retrograde at birth is marked ℞. Most charts have one or more; it describes how that planet’s qualities are lived, not whether they are lacking.

In practice

Each retrograde starts and ends with a station, and between them the planet crosses the same stretch of the zodiac three times: forwards, backwards, then forwards again. A slow planet can therefore make the same transit exact two or three times within one transit window.

A reading looks at three things: a planet retrograde at birth, a planet turning retrograde or direct in the sky over a point of the chart, and the stretch of the zodiac a retrograde covers, where its themes are gone over again.

Origin and history

Retrograde motion was the great puzzle of ancient astronomy: a model of the sky had to explain why the planets loop back. In the Almagest, about 150, Claudius Ptolemy did it with epicycles, each planet turning on a small circle whose centre travels along a larger one around the Earth. In 1543 Nicolaus Copernicus showed in De revolutionibus orbium coelestium that the loops follow from the Earth’s own motion around the Sun, which accounted for them far more simply.

Astrologers have long counted a retrograde planet as weakened: William Lilly’s Christian Astrology, 1647, lists retrogradation among a planet’s accidental debilities. Many astrologers today read it instead as a quality turned inward, slower to show and more reflective.

How Ulune calculates it

The Swiss Ephemeris gives every body’s speed along the zodiac, in degrees a day, at the chart’s moment. When that speed is below zero the body is moving backwards, and Ulune marks it ℞: the same test in a birth chart, in the transits and in the calendar. The calendar’s retrograde stretches run from one station to the next, each found to within half a second.