Ganymede's Galileo Regio region: A Growing Understanding

NOTE: This JPEG image is made available in order to share with the public the excitement of new discoveries being made via the NASA/JPL Galileo spacecraft. Galileo scientists are in the process of calibrating and validating this data. The full digital image necessary for scientific analysis will be released within one year of receipt of this orbit's last data.

This image is available only on the WWW; it is not available in hardcopy or other forms.

This view of the Galileo Regio region on Jupiter's moon Ganymede illustrates how our understanding of this dark terrain is improving as NASA's current Galileo mission builds on the work done by NASA's Voyager missions in 1979. High resolution images taken by the Solid State Imaging (CCD) system aboard the Galileo spacecraft (right) have dramatically improved our view over previous Voyager images (left) of the dark terrain on Ganymede. The Voyager 2 image on the left was taken in 1979 at a resolution of 1.1 kilometers (0.7 miles) per pixel (picture element) while the Galileo image on the right was obtained on June 27, 1996 as the Galileo spacecraft flew by at a closer distance, 7570 kilometers (4693 miles), from the surface of Ganymede and a resolution of 77 meters (253 feet) per pixel. The frame is 27 by 46 kilometers (17 by 29 miles). North is to the top and the sun illuminates the surface from the lower left. Discontinuous lines in the Voyager image are now seen as tall ridges bounding deep furrows, with a wealth of details showing mass movements down their steep icy slopes. Many more craters, at much smaller scales, are now visible. What was seen as a mottled dark terrain in the Voyager images is now known to have many bright hummocks and smooth dark patches mingled together at small scales.

Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/galileo.

Return to Galileo Ganymede 1 Images
Return to Countdown to Ganymede Home Page
Return to Project Galileo Homepage