The discovery is the first evidence of the existence of moonlets bridging the gap in size between the larger ring moons Pan and Daphnis -- both several miles in diameter -- and the much smaller ice particles that comprise the bulk of the rings.

The discovery might lead to a better understanding of the origin and formation of Saturn's rings and even the solar system as a whole, scientists said.

Astronomers say the disturbances are indicators of orbiting moons about 328 feet in diameter -- about the length of a football field -- large enough to exert an observable gravitational pull on the particles around them.

"The discovery of these intermediate-sized particles tells us that Pan and Daphnis are probably just the largest members of the ring population, rather than interlopers from somewhere else," said lead scientist Matthew Tiscareno.

Tiscareno, a Cornell research associate, describes the discovery in paper appearing in the March 30 issue of the journal Nature.