Starting today, 5 planets will be in retrograde motion, a first in over a decade. Mercury, Mars, Jupiter, Saturn, and Pluto (still a planet in the heart and minds of many) are now, at least as seen from Earth, moving backwards relative to their regular motion against the stars. Why does this happen?It's all an optical illusion caused by a faster planet overtaking a slower one. A real life comparison is when passing a slower car on the highway when the car you're passing appears to fall behind you even though both cars are moving forward.
Oh yes, this won't cause any crazy Earthly goings-on, either!