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Saturn's main rings, along with its moons, are much brighter than most stars. As a result, much shorter exposure times (10 milliseconds, in this case) are required to produce an image and not saturate the detectors of the imaging cameras on NASA's Cassini spacecraft. A longer exposure would be required to capture the stars as well. Cassini has captured stars on many occasions, especially when a target moon is in eclipse, and thus darker than normal. For example, see PIA10526 . Dione (698 miles, 1123 kilometers across) and Epimetheus (70 miles, 113 kilometers across) are seen in this view, abo…
