Possible origin found of Saturn's G-ring

Ithaca, N.Y. -- U.S. scientists said they might have identified the source of one of Saturn's more mysterious rings -- large, icy particles.

Data transmitted by the Cassini space probe suggested Saturn's G ring likely is produced by relatively large, icy particles that reside within a bright arc on the ring's inner edge.

Matthew Hedman, a Cassini imaging team associate at Cornell University and lead author of the study, said the particles are confined within the arc by gravitational effects from Saturn's moon Mimas. Micrometeoroids collide with the particles, releasing smaller, dust-sized particles that brighten the arc.

The plasma in the giant planet's magnetic field sweeps through the arc continually, dragging out the fine particles, which create the G ring, said Hedman.

The finding, he added, is evidence of the complex interaction between Saturn's moons, rings and magnetosphere. Studying that interaction is one of Cassini's objectives.

The research -- reported in the Aug. 2 issue of the journal Science -- is based on observations made by multiple Cassini instruments during 2004 and 2005.

The Cassini-Huygens mission is a project of the U.S. National Aeronautics and Space Administration, the European Space Agency and the Italian Space Agency.

Copyright 2007 by United Press International.