What Do Astronomers Mean When They Say Mercury Is In Retrograde?

What Do Astronomers Mean When They Say Mercury Is In Retrograde?
Astronomers have known about the planet’s apparent retrograde motion for centuries. Is there any truth to the astrological phenomenon?
By Sofia QuagliaJul 6, 2023 2:00 PM

Every three to four months, Mercury appears to travel backward across the sky and the internet becomes ablaze with worries about the mayhem that a Mercury retrograde has in store for us. Brands have even jumped on the bandwagon, offering Mercury retrograde merch, deals and sales.

To astrologists, this planet’s vocation is communication and tech; according to Roman mythology, Mercury was the god of messages. Therefore, a Mercury in retrograde is often associated with a range of misfortunes and miscommunications for those of us on Earth.

Yet we cannot blame the planet Mercury or its position in the sky for any mundane mishaps and communication issues we might be experiencing. If planets and stars affected life on Earth, things would be very different.




“I feel like life is chaotic as it is,” says Paul Byrne, an Earth and planetary sciences expert at Washington University in St. Louis. “I'd hate to think that the planets were having any kind of effectiveness, and I think we can pretty confidently say that they don't.”

Plus, most astrology is based on the classical planets, those we have known about for centuries and can see with the naked eye. But many more discoveries are added to our understanding of the universe every year.

What Is Mercury Retrograde?
Mercury retrograde is called “apparent Mercury retrograde” by astronomers because it’s an optical illusion. All planets travel around the sun in a counter-clockwise orbit; and in most cases, when we look up at the sky at night, they all appear to be traveling in that same direction.

But because not all planets travel at the same speed around the sun — and because they embark on differently sized orbits — sometimes Earth “laps” other planets. And sometimes, other planets lap us.

When we overtake a planet that is farther from the sun than us, like Mars, it can look like the planet is moving backward against a backdrop of stars. It’s the same phenomenon that occurs when you overtake a slower car while driving: It may appear as if the other car is not moving, or moving backward, but both vehicles are still traveling in the same direction.

On the flip side, when planets that are closer than us to the sun — Venus and Mercury — overtake us and begin to curl back around the sun, they also appear to be moving backward from our perspective.