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 / NASA

🔁 3 Planets Go Retrograde This July!⁠ ⁠ Heads up, skywatchers! In July 2025, Neptune, Saturn, and Mercury will all go retrograde — a celestial event where planets appear to move backward in the sky!⁠ ⁠ 🌀 What is retrograde motion?⁠ Normally, planets move from west to east across the sky (called prograde motion). But sometimes, due to the way Earth and other planets orbit the Sun, they appear to reverse direction for a while. This is called apparent retrograde motion — it’s just an optical illu