Cassini's ability to remain precisely and steadily pointed at targets such as Mimas (seen here) yields sharp images despite the relatively high speed at which the spacecraft is moving. Cassini was traveling at more than 13 kilometers per second when it acquired this view, which shows crisp detail on Mimas (396 kilometers, 246 miles across) against the backdrop of Saturn’s northern hemisphere. Shadows of the icy rings stretch across the atmosphere and are blurred due to spacecraft motion.
The part of Mimas visible here always faces away from Saturn as the moon orbits the giant planet. In scientific language, the moon is said to be “phase-locked.”
The image has been rotated so that north on Mimas (and Saturn) is up.
This view was obtained with the narrow angle camera on January 18, 2005, from a distance of approximately 1.25 million kilometers (777,000 miles) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 114 degrees. The image was taken using a combination of spectral filters sensitive to wavelengths of infrared and polarized light. Resolution in the image is 7 kilometers (4 miles) per pixel. The image has been contrast-enhanced to aid visibility.
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.