MAGELLAN PROJECT OFFICE


P-38160
4/23/91
                         

     This Magellan image is centered at 17 degrees north latitude
and 62.5 longitude in the northwestern Ovda Region of Venus.  The
image, which is 100 kilometers (62 miles) in width and 70
kilometers (43.4 miles) in length, is a mosaic of orbits 829-834. 
The image shows some spectacular wind streaks 500 kilometers (300
miles) northeast of the crater Mead.  Mead is the largest impact
crater known to exist on Venus with a diameter of 275 km (170
miles).  The large explosion associated with the impact spread
debris as much as 500 kilometers away from Mead on to the
surrounding plains.  The streaks in this image most likely
represent debris from the impact that has been modified by surface
winds.  It is difficult to determine whether there are bright
streaks on top of darker terrain or dark streaks on top of brighter
terrain.  If the streaks represent radar-bright debris then the
wind is blowing from the northwest to the southeast.  If the
streaks are composed of radar-dark material, then the wind
direction is reversed.  During the second cycle, Magellan
scientists will look at this area again to determine if there has
been any movement of the streaks.  Movement will indicate active
aeolian modification on the surface of Venus.


                    Jet Propulsion Laboratory
               California Institute of Technology
          National Aeronautics and Space Administration
                   Pasadena, California 91109