As Mars has grown closer and brighter daily for several months, it has gradually moved easterly in relation to background stars in the pre-dawn sky. That’s about to change as the red planet begins to backpedal in our sky, moving steadily westward. Astronomers call this backward motion “retrograde.” The shift comes as Mars is gradually becoming visible in the late evening, too, just in time for the historic close approach to Earth that will occur in late August.