Bruce Murray Space Image LibraryVoyager 1 mosaic of Rhea Voyager 1 mosaic of Rhea Voyager 1 obtained Cassini-like coverage of the northern hemisphere of Saturn's moon Rhea. NASA / JPL / Björn JónssonHere is a version with a superimposed coordinate grid. Voyager 1 mosaic of Rhea with superimposed coordinate grid Image: NASA / JPL-Caltech / Björn Jónsson