(1) The moonlet moves within this ring arc.

(2) The moonlet idea is still preliminary.

(3) This new moonlet, situated about 480 km (300 mi) inward from the outer edge of the B ring, was found by detection of its shadow which stretches 41 km (25 mi) across the rings.

(4) Maybe it was a onetime moonlet of Iapetus, explained Kevin Walsh of the Southwest Research Institute in Boulder, Colorado, at a recent planetary science meeting in France.

(5) The moonlet is too small to be resolved by Cassini's cameras, so its size cannot be measured directly.

(6) If the short-lived moonlet emerged from a debris disk, as Earth's moon did, the moonlet could have forced leftover debris onto Iapetus to form the walnut ridge.

(7) Scientists imaged the moonlet on Aug. 15, 2008, and then they confirmed its presence by finding it in two earlier images.

(8) The shadow length implies the moonlet is protruding about 200 meters, or 660 feet, above the ring plane.

(9) A solution of onboard laser - communication - and laser - range - finder for moonlet formate is introduced.

(10) For the first time, ground-based telescopes spotted a tiny moonlet orbiting a mere asteroid in Earth's own solar system.

(11) "Meteoroid impacts into, and collisions among, these bodies and the moonlet could liberate dust to form the arc, " said Hedman.

(12) Early next year, Cassini's camera will take a closer look at the arc and the moonlet.

(13) Previous Cassini plasma and dust measurements indicated that this partial ring may be produced from relatively large, icy particles embedded within the arc, such as this moonlet.