The Saturnian satellite Rhea was at first thought to have rings, but further investigation by the Cassini probe showed that Rhea probably does not have rings. The probe initially detected bands made of material ranging from the size of pebbles to the size of boulders around the satellite. Some scientists believe if the rings exist, their light scattering is too weak or they are too wispy to be detected by instruments.
Scientists were alerted to the possibility that Rhea might have rings because something around it was pulling energetic electrons from Saturn's magnetosphere. At first, they believed that solid material such as a ring or disc around Rhea was doing this.
Scientists who believe that Rhea has rings post that there might be three rings or disks. The first has a radius of about 1615 kilometers, the second has a radius of about 1800 kilometers, and the third has a radius of about 2020 kilometers. If the rings exist, it is possible that they are what's left of a smaller object that was captured by Rhea or some kind of impact that threw debris into orbit.
Rhea might have had rings in the past, for blue marks at the equator might be evidence of debris impacting the moon at some point.