In this photograph of Rhea, taken by the Cassini orbiter, there are sections near the terminator that are very blurred, a stark contrast from the crisp sharpness of the rest of the image. The blurred sections look polygonal in shape, with defined edges.
Return to Rhea (PIA19057). Zoomed in to the terminator, blurred portion highlighted. Courtesy NASA JPL.
Why are these portions blurred? My theory is that Cassini could not take photographs of those regions with its narrow-field camera, and hence used wide-field data instead. Am I right?