The true scientific meaning of Mercury entering retrograde

Throughout almost all of the year, you can see planet migrating through Earth’s night sky in the same predictable fashion. Whereas the stars always appear in the same location relative to one another, the planets — being so close by relative to the distant stars — appear to shift from night-to-night. Most of the time, these distant worlds slowly migrate in the same direction: typically from west to east, rising and/or setting slightly later from their relative positions a day earlier. But every once in a while, if you were to track a planet’s motion continuously over time periods lasting weeks-to-months, you’ll find that a planet suddenly slows it migration, eventually stopping entirely as it repeats its position from the previous night. Then, for the next few weeks, it actually reverses its direction in what’s known as a retrograde period, migrating in the opposite direction to its more typical motion, eventually moving to where it was weeks prior. Finally, it will slow down again, reverse its course once more, and continue on moving in its original direction: in prograde motion again. <a href="https://medium.com/starts-with-a-bang/the-true-scientific-meaning-of-mercury-entering-retrograde-f390c16698d5">Learn More</a>