Saturn's moon Dione, a thousand-kilometre-wide ball of ice around a rocky core, as photographed by NASA's Cassini probe. The scratches are bright-walled canyons on the moon's surface.
Image credit: NASA/JPL/Space Science Institute
Image details (from the Cassini multimedia pages): The image was taken in visible light with the Cassini spacecraft wide-angle camera on Sept. 30, 2007. The view was acquired at a distance of approximately 45,000 kilometers (28,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 36 degrees. Image scale is 3 kilometers (2 miles) per pixel.