Posted: Mon, Dec 10, 2007, 8:41 AM ET (1341 GMT)
Several years' worth of images collected by NASA's Cassini spacecraft have allowed scientists to measure the unusual shapes of some of Saturn's small moons and thus understand their origins. In papers published in the latest issue of the journal Science, researchers analyzing the Cassini images of Saturn's moons believe that these moons started out with a massive core, in the form of debris from another moon that broke apart. Ring particles agglomerated around those cores, allowing the moons to grow. Without those cores, according to scientists, ring material would not clump together on its own to create the moons. Giant equatorial ridges on some of the small moons, giving them the appearance of flying saucers, might be explained by "fossilized" accretion disks created after Saturn's rings narrowed to their current thinness.

Related Links:

•  SPACE.com article
•  New Scientist article
•  Discovery.com article
•  NASA/JPL press release