Apparent Retrograde Motion of Mars - This animation shows the apparent retrograde motion of Mars in as seen from Earth - Created by : Eugene Alvin Villar (seav), as part of the Philip Greenspun illustration project
Retrograde: ~Mars appears to reverse its course in the night sky. This image by Tunc Tezel shows the retrograde motion by layering images in time series. The dotted line to right is Uranus doing the same thing.
Venus - one day is longer than its entire year. It takes Venus 243 Earth days to completely rotate on its axis, but just 225 days to orbit the sun. Venus is one of two planets that rotates in reverse, called retrograde motion.
This composite of images spaced some 5 to 7 days apart from late October 2011 (top right) through early July 2012 (bottom left), traces the retrograde motion of ruddy-colored Mars through planet Earths night sky.