NASA spacecraft spots new moonlet in Saturn’s ringsMarch 4th, 2009 - 12:52 pm ICT by IANS
Washington, March 4 (Xinhua) Scientists have found a new moonlet hidden in one of Saturn’s dazzling outer rings, the Scientific American website has reported.
Saturn’s G ring, a faint band of material near the outer bounds of the planet’s famed ring system, hosts a bright arc about 150,000 km long.
The arc, or partial ring, which stretches through about a sixth of the G ring’s length, is believed to provide the rest of the ring with dust and ice, but its evolution has remained a mystery.
Recent images from NASA’s Cassini spacecraft point to a moonlet embedded in the G ring. The moonlet, the Cassini team speculates, might help to re-populate the arc, and then the ring as a whole, with material as it suffers collisions with meteoroids or other small bodies within the ring.
The moonlet, which showed up as a bright speck in the ring’s arc, appears to be approximately 0.5 km in diameter, based on its reflectance. The finding was reported Tuesday in a circular from the International Astronomical Union.
“Before Cassini, the G ring was the only dusty ring that was not clearly associated with a known moon, which made it odd,” Matthew Hedman, an astronomy research associate at Cornell University and a member of the Cassini imaging team, said in a statement.
Data from the same mission in 2007 indicated that the ring-feeding arc could stem from an orbital relationship with Mimas, one of Saturn’s proper moons, but the arc’s composition remained a puzzle.
“The discovery of this moonlet, together with other Cassini data,” Hedman said, “should help us make sense of this previously mysterious ring”.
Tags: arc, astronomy research, cassini imaging team, cassini spacecraft, collisions, cornell university, dusty ring, faint band, international astronomical union, mimas, moons, mysterious ring, nasa, nasa spacecraft, outer rings, reflectance, research associate, scientific american, speck, xinhua