PASADENA, Calif. - New observations made by NASA’s Cassini spacecraft suggest that Rhea, the second-largest moon of Saturn, may have rings. If the rings were confirmed, it would be the first moon to have a ring system around it.

The Cassini spacecraft had detected a large debris disk which appeared to be like rings around the 950-mile-wide moon Rhea. Scientists firmly believe that the discs are composed of particles ranging from the size of pebbles to big rocks.

In contrast to the rings around Jupiter, Saturn, Uranus and Neptune, the alleged arcs around Rhea remain invisible and cannot be seen directly. Scientists confirmed the existence of arcs based on the measurements made by Cassini, which detected a fall in electrons on both sides of the moon, indicating that the existence of rings was absorbing the electrons.

This is an artist concept of the ring of debris that may orbit Saturn’s second-largest moon, Rhea. The suggested disk of solid material is exaggerated in density here for clarity.

Credit: NASA/JPL/JHUAPL

It’s uncertain that when the rings would have originated, one thing is certain that they originated as a result of a collision of an asteroid or comet which took place long ago that disgorged the debris around Rhea.

(more…)