Therefore the finders , led by Geraint Jones of the Cassini MIMI team , argue that the decrease of electrons must be caused by solid particles orbiting Rhea : An analysis of the electron data indicates that this obstacle is most likely in the form of a low optical depth disk of material near Rheaâ s equatorial plane and that the disk contains solid bodies up to ~ 1 m in size . Therefore the discoverers , led by Geraint Jones of the Cassini MIMI team , argue that the depletions must be caused by solid particles orbiting Rhea : An analysis of the electron data indicates that this obstacle is most likely in the form of a low optical depth disk of material near Rheaâ s equatorial plane and that the disk contains solid bodies up to ~ 1 m in size .