... Jupiter and Saturn Pas de Deux . ... 20.12.2001 . ... Credit: Tunc Tezel Explanation: Viewed from Earth, the solar system's planets do a cosmic dance that is hard to appreciate on any single night. ... It reveals the graceful looping or retrograde motion of bright wanderers Jupiter (leftmost) and Saturn. ... Retrograde motion can be seen each time Earth overtakes and laps planets orbiting farther from the Sun, Earth moving more rapidly through its own relatively close-in orbit. ... December 2001 . ...