What exactly happens during Mercury's retrograde, and why do we tend to blame it for everything?

From malfunctioning computers to missed flights and workplace drama, astrology enthusiasts might say that chaos is inevitable when Mercury goes retrograde. In fact, we began 2024 with Mercury in retrograde: the final retrograde of 2023 wrapped up on January 1st. But it's not the only retrograde period this year—check the chart below for the remaining Mercury retrograde dates of 2024.

However, an astronomer suggests there's no need to panic and stay indoors when this celestial event occurs. According to Dr. Mark Hammergren, a former astronomer at Chicago's Adler Planetarium, there's no known physical cause for events like power outages or changes in people's behavior. So why, if Mercury's backward motion doesn't disrupt our lives, do so many people believe that it does?

The Origins of the 'Mercury in Retrograde' Phenomenon

Mercury retrograde—its official term—was first discussed in astrological circles in the mid-18th century. It was recorded in British agricultural almanacs of the era, where farmers used it to align their planting schedules with celestial patterns.

During the Victorian spiritualism boom, astrology saw a surge in popularity, with many believing that the stars influenced earthly events in a variety of often troublesome ways. In the late 19th century, publications like The Astrologer’s Magazine and The Science of the Stars linked Mercury retrograde with heavy rainfall. Articles from that period also referred to the event as an “ill omen,” though its connection to widespread disaster was less emphasized than it is today.

While other spiritualist practices like séances and crystal gazing began to decline, astrology flourished. By the 1970s, horoscopes were a regular feature in newspapers, and Mercury retrograde became a familiar topic. As the Roman god Mercury was believed to govern travel, commerce, wealth, and communication, the planet Mercury became associated with these domains in astrological practice as well.

The influence attributed to Mercury retrograde has grown so exaggerated that it is now blamed for everything from digestive issues to malfunctioning washing machines.

What exactly is Mercury in Retrograde?

Despite the growing anxiety around Mercury retrograde, there's still no credible evidence suggesting it's something to fear. Even the weakest theories, like the notion that Mercury’s gravitational pull impacts our bodies' water in the same way the moon affects ocean tides, are quickly debunked by science. 'A car 20 feet away from you exerts a stronger gravitational pull than Mercury does,' said Dr. Hammergren.

To grasp how little Mercury retrograde affects life on Earth, it's useful to understand the physical process behind the phenomenon. When the planet closest to the sun is in retrograde, it seems to move 'backwards' (from east to west, instead of west to east) across the sky. This apparent reversal in Mercury's orbit is merely an illusion for those observing it from Earth. Imagine Mercury and Earth orbiting the sun like cars on a racetrack. A year on Mercury lasts only 88 Earth days, compared to Earth's 365 days, so Mercury completes four orbits in the time it takes Earth to complete one.

When the planets are aligned on the same side of the sun, Mercury appears to move eastward to observers on Earth. However, as Mercury passes Earth and continues its orbit, its straight path seems to change direction. Dr. Hammergren explains that this is simply a perspective trick: 'It’s like passing a car on the highway, maybe going a bit faster than they are. They’re not actually moving backwards, it just seems like they are compared to your motion.'

Earth's orbit is unique in the solar system, meaning that all planets appear to move backwards at different times. Planets farther from the sun than Earth display more noticeable retrograde movements because they are visible at night. Yet, astrology has turned Mercury's retrograde motion into the one that sparks dread every few months.

Dr. Hammergren attributes the superstition surrounding Mercury, and astrology in general, to confirmation bias: '[Believers] will say, ‘Aha! There’s a disruption in my workplace because Mercury’s retrograde.’' He encourages people to look back over the past year to see if the periods when Mercury was retrograde were particularly catastrophic. They’ll likely find that communication breakdowns and technical issues are common throughout the year. But as Dr. Hammergren pointed out, when things go wrong and Mercury isn’t retrograde, 'we don’t get that hashtag. It’s called Monday.'