If you have friends who reference astrology but don’t follow it much yourself, you may have heard people complaining about, or dreading, something called Mercury retrograde. But what is it?
Mercury Retrograde Dates for 2021
- January 30 – February 19
- May 29 – June 21
- September 27 – October 17
Mercury Retrograde Dates in 2020
Below were last year’s dates:
- February 16 – March 9
- June 18 – July 12
- October 13 – November 13
What does Mercury Retrograde mean?
The term retrograde comes from the Latin word retrogradus, which literally means “backward step.”
As the name suggests, retrograde is when a planet appears to go backward in its orbit, as viewed from Earth. Astronomers refer to this as “apparent retrograde motion,” because it is an optical illusion.
The opposite of retrograde is direct or prograde motion. Prograde motion is the term astronomers prefer, while astrologers are more prone to use the term “direct” motion.
Every planet in our Solar System travels in the same direction in its journey around the Sun, and none of them ever pause and turn back in the opposite direction. Yet, all of them appear to do just that from time to time.
Because of the Earth’s daily rotation, the objects in the night sky appear to “move” from east to west through the night sky. While the location of the stars relative to the Earth is fixed, at least from our vantage point, the other planets in our Solar System all orbit the Sun at varying speeds.
The outer planets — Mars, Jupiter, Saturn, Uranus, and Neptune — all take longer to orbit the Sun than the Earth does, because their orbits are larger. Because of this, the Earth often laps these planets in its journey around the Sun.
When the Earth overtakes an outer planet, that planet appears to travel backward, as compared to the stars, for a time.
Picture two cars on the highway going in the same direction in different lanes. If one car is driving faster than the other, the slower car will appear to go backward from the perspective of a person in the faster car, even though the slower car is still going pretty fast in the same direction.
For the inner planets, Mercury and Venus, the mechanism that causes them to turn retrograde is the same, but in reverse. Mercury and Venus appear to go retrograde when they lap us.
Because Mercury completes its orbit around the Sun in only 88 days, the Swift Planet becomes retrograde three or four times in a calendar year, for about three weeks at a time. Outer planets have less frequent, but longer-lasting, periods of retrograde motion.
Why Dread It?
So what does all of that have to do with people wanting to hide in their rooms for weeks at a time?
Astrologers believe that the Moon, stars, planets, and Sun affect happenings here on Earth and that each planet in our Solar System rules a different aspect of life.
Like the Greek messenger god it was named for, Mercury is said to govern transportation and communication.
Those who dread Mercury’s retrograde motion say that, when the planet travels backward, its power to positively influence these domains is stifled, leading to chaos.
Believers in the malevolent power of Mercury retrograde blame the phenomenon for everything from arguments to lost mail or luggage to automobile accidents and warn people to hold back on conducting important business during this time.