* Mercury’s retrograde motion * This video explains Mercury’s apparent retrograde motion in our skies: the inner planet appears to retrace its steps a few times per year. Every planet does this, every year. Retrograde motion is an optical illusion caused by differences in the planets’ orbital speeds. When a planet seems to reverse its direction in the sky, it’s called retrograde motion (from the Latin word retrogradus – "going backward"). Courtesy: Star Walk Based on video by James O'Donoghue /

Star Walk - Jupiter and Saturn go retrograde 🪐 This video...

Planets usually move across our night sky from west to east relative to the background stars. This steady motion is a result of their orbits around the Sun. But every so often, a planet like Mars appears to hit the brakes, reverse direction, and move backward - a puzzling motion known as retrograde. This animation breaks down the mystery behind retrograde motion, focusing specifically on Mars. You'll see how the motion of Earth and Mars in their respective orbits creates the illusion of Mars loo

The onset of retrograde motion means that Earth and Mars are converging. At closest approach on Dec. 1st the two worlds will be just 0.545 AU apart, providing spectacular views through backyard telescopes. Less than a week later on Dec. 7th the Moon will pass in front of Mars, creating a lunar occultation visible from parts of the Americas, Europe and Northern Africa. Retrograde motion will continue through Jan 12, 2023, and lots will happen between now and then. 📑 Spaceweather | The Watchmen's