What Does "Retrograde" Mean?

The most common retrograde meaning is “moving backward.” It comes from the Latin retrogradus (retro meaning “backward,” gradus meaning “stepping”).

As an adjective, retrograde can describe anything that is moving away from its original forward motion.

• Even though our progress is in retrograde, I think we’ll turn a profit this quarter.
• John’s father constantly embarrasses him with his retrograde, out-of-touch comments.
• Venus and Uranus are the only planets that spin retrograde on their axes.
• In her next book, Martha explores the retrograde effect of living in the past.
• The Supreme Court’s retrograde decision set American politics back for decades.

In astronomy, retrograde refers to the optical illusion of a planet moving backward in the sky. When a planet is in prograde, it moves from west to east in the sky — until Earth passes a slower planet in orbit. 

Because each planet orbits the sun at a different speed, our viewpoint from Earth can make it look like certain planets are moving backward (east to west), when really, Earth has just passed them.

Retrograde periods typically last between a few weeks to a few months, depending on the planet.

Venus and Mercury, which have shorter orbits than Earth, go into retrograde when they pass Earth.

At 88 days, Mercury has the shortest orbit in the solar system — which is why Mercury retrograde is the most common of the planetary retrograde periods.

In astrology, which focuses on the relationships between planetary positions and human behavior, the period of Mercury retrograde usually indicates that a disruption or “backward” movement of your plans will occur. Astrologists warn not to move forward with new projects or risky ventures during these periods.

If someone is acting odd, your phone is glitchy, or bizarre news has ruined your day, it’s not uncommon to say “Mercury must be in retrograde.”

• Mercury is in retrograde, so don’t make any big changes to your life right now.
• Look at all these crazy drivers. Mercury must be in retrograde.
• I’m sorry — I can’t go out during Mercury retrograde. Too risky.

If you’d like to know when Mercury retrograde will occur (either to prepare your telescope or to emotionally prepare), it’s easy to predict based on astronomical patterns. It happens three or four times every calendar year.

A common meme to describe Mercury retrograde is “Mercury in the microwave.”

Social-media users use the phrase to complain about the chaos they experience during Mercury retrograde (which kind of sounds like microwave).