The leading hemisphere of Dione displays linear grooves and subtle streaks in one Cassini view, while another view shows subtle variations in color across the moon's surface.
The monochrome image was taken in wavelengths of polarized infrared light. To create the false-color view, ultraviolet, green and infrared images were combined into a single black and white picture that isolates and maps regional color differences. This "color map" was then superposed over a clear-filter image. The origin of the color differences is not yet understood, but may be caused by subtle differences in the surface composition or the sizes of grains making up the icy soil.
Terrain visible here is on the moon's leading hemisphere. North on Dione (1,123 kilometers, 698 miles across) is up and rotated 17 degrees to the right.
All images were acquired with the Cassini spacecraft narrow-angle camera on Dec. 24, 2005 at a distance of approximately 597,000 kilometers (371,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 21 degrees. Image scale is 4 kilometers (2 miles) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.