First Galileo Images of Ganymede to be Released July 10
Douglas Isbell Headquarters, Washington, DC July 8, 1996 (Phone: 202/358-1753) Mary Beth Murrill Jet Propulsion Laboratory, Pasadena, CA (Phone: 818/354-5011) NOTE TO EDITORS: N96-46
The Galileo orbiter flew by Jupiter's large, icy moon Ganymede at 2:29 a.m. EDT on June 27, passing within 519 miles (835 kilometers) of Ganymede at a relative speed of about 17,448 miles per hour.
Initial processing of the sections of the Ganymede images to be released showed an enormous increase in sharpness and surface detail over earlier images of Ganymede returned by the historic Voyager flyby missions in 1979. (Galileo flew 70 times closer to Ganymede than Voyager 2.)
With a diameter of 3,269 miles (5,262 kilometers), Ganymede is the largest moon in the Solar System -- bigger than Mercury and about three-quarters the size of Mars. It possesses a variety of familiar Earth-like geologic formations including craters and basins, grooves and mountains. The bulk of the satellite is believed to be about half water ice and half rock. Portions of its surface are relatively bright, clean ice while the other regions are covered with darker "dirty" ice. The darker areas appear to be ancient and heavily cratered, while the lighter regions display evidence of tectonic activity that may have broken up the icy crust.
The Galileo Mission Update program will be broadcast live on NASA Television with two-way question and answer capability from participating NASA locations. NASA Television is carried on Spacenet-2, transponder 5, channel 9, at 69 degrees West longitude, frequency 3880.0 MHz, audio 6.8 Megahertz.
Galileo's images of Ganymede also will be posted to the World Wide Web, on the Galileo mission home page at:
In the event that heavy Internet traffic makes it difficult to reach the main site, users may also try the following mirror sites: