On Wednesday April 8th in a move that comes about annually, Jupiter will once again reverse its direction from moving toward the west to moving toward the east.
For about the past 4 months Jupiter has appeared to be moving westward (toward the right) rather then toward the east. This happens as the faster moving Earth catches up with and then passes by Jupiter. This apparent westward motion of Jupiter is known as retrograde motion and for Jupiter it’s retrograde motion comes to an end on the 8th when Jupiter resumes its normal orbital motion toward the east, or to the left as we view Jupiter from the Earth.
Since retrograde is a reference to motion and means backward or reverse motion, then the opposite of retrograde would be prograde motion. So it would be correct to describe Jupiter as having resumed prograde motion. However you would probably get a blank look from those you say this to! So stick with “direct motion” or just say that Jupiter orbits the Sun to the east as we see it from Earth.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.