Chances are, you’ve probably heard complaints about the planet Mercury entering retrograde, but what exactly does this mean and why do so many people care? Whether or not you’re convinced that there’s any merit to astrology, some concepts from both astronomy and astrology will help you understand what all the fuss is about.
What on Earth Does Retrograde Mean?
“Retrograde” is shorthand for “apparent retrograde motion” and describes how planets appear to stop and then move in the opposite direction of their normal paths across the nighttime skies. Contrary to how this looks when observed from Earth, these planets don’t travel in reverse. Christopher Crockett of EarthSky explains that this visual illusion occurs when Earth passes or is passed by another celestial body, tricking us into thinking that the other planet is moving backward. This phenomenon also confused ancient astronomers, since they followed Claudius Ptolemy’s geocentric model in which the sun and other planets orbited around Earth.
And Yet It Moves
The geocentric model remained mostly unchallenged until Polish scientist Nicolaus Copernicus argued for a heliocentric view in 1543. His ideas were later endorsed and expanded upon by both German astronomer Johannes Kepler and Italian scholar Galileo Galilei through his own carefully documented telescope observations. Unfortunately, Galileo’s ardent defense of heliocentrism prompted the Catholic Church’s Roman Inquisition to accuse him of heresy during the early 1600s.
Yet in modern times, the “heresy” of Copernicus, Kepler, and Galileo is now a scientific fact and better explains the retrograde phenomenon. In fact, every planet in our solar system can appear to reverse course when viewed from Earth. The time each one takes to travel around the sun affects both its retrograde duration and frequency. Distant planets like Saturn and Neptune retrograde only once a year and can spend months in this state, while Mercury retrogrades three to four times per year for about 21 days at a stretch.
What’s the Deal With Mercury Retrogrades?
If every planet can retrograde, why does Mercury get most of the attention? The answer lies both in science and in ancient religions practiced around the Mediterranean. Some key facts about this planet prove to be illuminating:
- Mercury’s circumference at its equator is only 9,525.1 miles, making it the smallest planet in our solar system.
- It travels in an elliptical orbit, with its distance from the sun varying from 29 million to 43 million miles.
- It has the shortest orbital period in our solar system, clocking in at 87 days, 23 hours, 16 minutes, and 48 seconds.
This speedy little ball of iron and silicates is aptly named after the swift-footed messenger of the Roman deity pantheon. The ancient Romans associated him with the Greek god Hermes, but the Babylonians called the planet Nabu after their own divine messenger.
Meanwhile, Time editor Wilder Davies clarified in a March 2018 article that retrograde has a negative meaning in astrology. Since Mercury, Hermes, and Nabu were all associated with communication and both the Greek and Roman versions were thought to govern commerce, this planet’s retrograde is regarded as heralding possible misunderstandings, disagreements, and logistical problems. Everything from botched contracts and failed business ventures to lost mail and relationship troubles is blamed on this pint-sized planet’s backward motion in the night skies.
An Ancient Art in Modern Times
Astrology is often dismissed as pseudoscience, but modern audiences remain fascinated by it. Some aspects can be found in various mystic traditions, present-day New Age spiritual movements, and even popular culture. The wide reach of social media and the ease of researching planetary movements have also caused many astrological concepts to become common knowledge. Whether jokingly in memes or within the true worries of everyday people, the influence of Mercury and its troublesome retrogrades are still felt today.