Grooved terrain in this area of Nippur Sulcus on Jupiter's moon Ganymede is composed of ridges and troughs spaced 1 to 2 kilometers (0.6 to 1.2 miles) apart. North is to the top. A few broad (4 to 5 kilometer (2.5 to 3.1 mile) wide) ridges such as those in the northeast and southwest corners have smaller ridges on top of them. A 12 kilometer (7 mile) diameter impact crater is superimposed on these ridges. A dark ring at the base of the crater walls may be due to a collection of dark material at the base of the steep slopes. The image is 49 by 41 kilometers (30 by 25 miles) with a resolution of 200 meters (656 feet) per picture element (pixel). This image was obtained on September 6, 1996 by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft.
The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).
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://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo.