Mercury is a little-known and still mysterious world.
But one thing is for sure. Mercury is the closest planet to the sun and cannot actually retrograde and does not affect us here on Earth. The concept of Mercury retrograde is a common reference in astrology, where communication and travel are temporarily impaired, and can certainly be an interesting thought. This event occurs when Mercury appears to begin moving in opposite directions across the sky.
But this is a subtle deception. Mercury retrograde is visual motionsuch as when you pass a speeding car on the highway, it appears that the car is moving backwards. This is not a special or significant event.
“There’s nothing unusual about this,” Tansu Daylan, a physicist at Washington University in St. Louis and leader of NASA’s telescope observations, told Mashable.
NASA scientists view the first Voyager images. What he saw made him shudder.
This happens so often—three or four times a year—that some people easily associate an incident (a misunderstanding or travel dilemma) with the incident. “People are actively looking for connections,” Dailan said.
What is the reason for Mercury retrograde?
From our perspective, the planets, including Mercury, move from west to east relative to the stars in the night sky. In fact, Greek and Roman astronomers called planets “wandering stars.”
Mix and match speed of light
Hypothetically, if you could look down at the Sun from above, you would see the planets rotating counterclockwise. This creates an eastward movement from our habitat on Earth. but Dailan emphasized that this situation changes when the two planets orbit the sun. The inner planet (Mercury) then moves faster than the outer planet (such as Earth), resulting in “apparent retrograde motion”— obvious Because Mercury orbits our star at more than 100,000 mph, it doesn’t suddenly start moving backward.
The NASA chart below shows apparent retrograde motion using Mars and Earth. When planets align or one planet “passes” another, the planet’s appearance in the sky may change, but the actual orbit does not.
Description of apparent retrograde motion.
Image source: NASA
Mercury’s southern hemisphere as captured by NASA’s Messenger spacecraft.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Mercury retrograde lasts for weeks at a time, so don’t be surprised when you hear about its connection to numerous events. Notably, it was last launched again on August 5, 2024 – following a global Crowdstrike outage.
Even though we know Mercury’s orbit doesn’t do anything weird throughout the solar system throughout the year, it remains a mysterious world. This is a difficult planet to observe from Earth because of its proximity to the sun. “This means it can only be spotted shortly before sunrise and briefly after sunset, and always appears near the horizon,” explains the European Space Agency. What’s more, getting there is extremely challenging – anyone in Spacecraft working there must contend with the sun’s powerful gravitational pull. This is why Mercury is the least visited of the other inner planets. And, getting too close to Mercury is dangerous because the planet’s scorching surface is hot enough to melt lead and radiate the heat into space. The ongoing BepiColombo mission is a joint European and Japanese effort designed to withstand these extreme conditions as it conducts an unprecedented flyby.
Planetary scientists hope to answer many questions about Mercury soon: Is there water? Is it geologically active? How did it get so close to the sun?
But at least its strange apparent movements are well known.
“It’s nothing special,” Dailan said.
