What does “Mercury Retrograde” mean scientifically? understand the phenomenon

For people who believe in astrology, Mercury retrograde can mean many things, but mostly negative consequences for everyday life.

This phenomenon, however, exists and can be explained scientifically. According to NASA, the United States space agency, retrograde motion is an apparent change in the motion of the planet in the sky.

That means it’s not real, because the planet doesn’t physically start receding in its orbit. “It seems so due to the relative positions of the planet and Earth and the way they move around the Sun”, says the organization.

Generally, planets move from west to east across the stars at night. This is known as progressive movement.

Periodically though, that motion changes and they move east to west across the stars, which is called retrograde motion.

The explanation for retrograde motion in a heliocentric model—a solar system centered on the Sun—is that retrograde occurs approximately when a faster-moving planet catches up with and overtakes a slower-moving planet.

That is, retrograde motion is an optical illusion caused by the movement of all planets at different speeds from each other.

According to Carolyn Ernst, a planetary scientist at the Applied Physics Laboratory at Johns Hopkins University and vice chair of NASA’s Mercury Exploration Evaluation Group, it’s like driving on a highway with multiple lanes in the same direction.

When overtaking a car in another lane that is going slower, it may appear as if it is moving backwards compared to you despite going in the same direction, and vice versa. This is what happens when Mercury revolves around Earth.

Mercury’s apparent backward motion occurs over a few weeks, roughly every four months. Currently, Mercury retrograde started on the 23rd of August and will last until the 14th of September. The phenomenon happens again from December 13th to January 1st.