“Mercury retrograde is coming back, my darlings.”

Sadicka, an astrologer and spiritual life coach, is telling her 5,000 Instagram followers to watch out for technology issues, trouble communicating with people and even car accidents, ahead of the planet Mercury going into retrograde from 4 August.

A few times a year, Instagram and TikTok are flooded with cautionary posts like this one – as well as more tongue-in-cheek content (think: “POV: you blame all of your problems on Mercury being in retrograde instead of actually dealing with them”).

Mercury is the closest planet to the Sun and Mercury retrograde is an optical illusion which occurs three or four times a year, making the planet appear to move in the opposite direction than it usually does.

It is a similar effect to when one car overtakes another and, to those in the faster car, the slower vehicle appears to be moving backwards. All planets appear this way from Earth at various points, as they orbit the Sun at different speeds.

People have observed Mercury going into retrograde for thousands of years, and many believers in astrology (the influence of stars and planets on interpersonal events) link it to an increase in personal problems.

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Lina Sahhab, a 42-year-old who works for a non-profit, tells the BBC that she once believed superstitions surrounding Mercury were just that.

“Then I started noticing that the obstacles in my life really happen when there is a Mercury retrograde,” she says.

“My laptop would suddenly stop working, or I would buy something that has to do with technology that would not function properly.”

The lack of evidence for astrology doesn’t harm its popularity, especially on social media.

In an era where we can both predict the weather and find answers to most of our questions on Google, astrology enthusiasts often look to horoscopes for guidance on things most humans still feel they have little control over – like romance, friendship or even technology.

Perhaps it is no coincidence that, according to Google Trends, searches for “birth chart” and “astrology” both hit five-year peaks in 2020, during the Covid-19 pandemic, a time of immense uncertainty.

While astrology is now considered a pseudoscience, in the ancient civilisations in which it was first conceived, people needed ways to help them predict things like the timing of rainfall, temperature, wind and sunlight – and doing so was a survival skill.

Astrology can be traced back to between 3000BC and 2001BC to a region of West Asia then known as Mesopotamia. From there, it spread to India, and it eventually started to look more like it does now during the Hellenistic period (323BC to 31BC) in Ancient Greece.

According to Dr Nicholas Campion, professor of cosmology and culture at University of Wales Trinity Saint David, the Mercury retrograde phenomenon was discovered during the final century BC – but it wasn’t always interpreted as it is today.

Dr Campion says that in medieval times, if someone was trying to answer a question by plotting an astrological chart, Mercury being in retrograde was taken as a sign the answer was negative, or that something was “unlikely to happen”.

“It is only in the 20th century, in the astrology of the English-speaking world, that it came to mean ‘delays’ in particular,” says the astrology expert, adding that this interpretation took over in the 1980s.

Dr Campion says modern astrologists who subscribe to the influence of Mercury retrograde believe it means plans are going to be put on hold, or it is a bad time to start a new job or begin something new.

“It is very much a feature of a particular strand of western astrology,” he says. “Western astrology now spreads all over the world through social media and apps, so it is becoming global.”

Dr Campion says Mercury retrograde didn’t always have the same prominence that is does today: “It was always a very minor phenomenon in astrology.”

“Whilst astronomy and astrology may have been more closely rooted in the past, the general scientific consensus at present is that astronomical phenomena like retrogrades don’t have any predictable effect on people’s lives,” says Dhara Patel, of the National Space Centre in Leicester.

If science suggests Mercury retrograde may not have any bearing on our lives, why do so many people still turn to the stars for answers?

Some studies have linked belief in horoscopes and zodiac signs to “confirmation bias”, the tendency to believe or remember information that aligns with our pre-existing beliefs, and interpret it selectively to support them.

Zeinab Ajami, a clinical psychologist undertaking humanitarian mental health work in Ukraine, tells the BBC that “people tend to believe things that make them feel relieved or comfortable, and that do not require the brain to constantly analyse and reassess”.

She says astrology may provide a “fast and easy explanation” for difficult events, without the need for people to look at the “multiple layers to their problems”.

But many find star signs a gateway to inspiration, entertainment or some spiritual solace.

Mireille Hammal, a Beirut-based specialist in Reiki (a complementary therapy and form of energy healing), says clients who believe in the influence of the Mercury retrograde “usually avoid purchasing electronics during that period, or postpone signing contracts, moving to a new home or taking the step of getting married or engaged”.

Ms Hammal acknowledges that “a lot of people consider astrology to be just nonsense” but believes that it can be helpful to people as long as they avoid “reaching the point of obsession”.

Dr Campion, who runs an MA in Cultural Astronomy and Astrology, believes Mercury retrograde found popularity due to its simplicity – but says this can undermine how professional astrology is perceived.

“[Mercury retrograde] almost does not need any interpretation,” he says. “It’s not complicated or complex, and it applies to everybody.

“This idea that this is either a good or bad time for making plans really undermines the idea that astrology can be complex and nuanced,” he continues. “Because the fact is lots of things happen very well when Mercury is in retrograde.”

Mercury retrograde graphic created by Rafael Chacon