The boundary between the bright terrain of Harpagia Sulcus (right) and dark terrain of Nicholson Regio (left) areas of Jupiter's moon Ganymede springs out when viewed through red/blue 3-D glasses, in this image taken by NASA's Galileo spacecraft as it flew by Ganymede on May 20, 2000.

Details of the rough, ancient, heavily cratered dark terrain of Nicholson Regio are in stark contrast to the very smooth, bright, young terrain of Harpagia Sulcus. In the center lies the transition to the boundary between these two regions, providing evidence that extensional faulting marks the boundary. A series of steep slopes deform the dark terrain close to the boundary. In the bright terrain, a deep trough and flanking ridge delimit the boundary.

North is to the top of the picture. The Sun illuminates the surface from the left. The imaged region, centered at ~14 degrees latitude and 319 degrees longitude, covers an area approximately 25 by 10 kilometers (15.5 by 6 miles.) The resolutions of the two data sets are 20 meters (66 feet) per picture element and 121 meters (397 feet) per picture element. The higher resolution images were taken at a range of 2,000 kilometers (about 1,200 miles).

The Jet Propulsion Laboratory, Pasadena, Calif., manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . The image was produced by the German Aerospace Center (DLR),http://solarsystem.dlr.de and Brown University,http://www.planetary.brown.edu/. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo