Cassini 2007

Luis França

23 Mai 2006
Saturn's 'flying saucer' moons built of ring material


Two of Saturn's small moons look eerily like flying saucers, new observations by the Cassini spacecraft reveal. The moons, which lie within the giant planet's rings, may have come by their strange shape by gradually accumulating ring particles in a ridge around their equators.

Both moons have a flattened shape, being wider than they are tall. But their uncanny resemblance to UFOs only became clear recently when Cassini viewed them with its powerful cameras. It found that the smooth ridges girdling their equators lie in the same plane as Saturn's rings and are also as thick as the vertical distance that the moons appear to travel as they move through the rings.

Now, scientists led by Sébastien Charnoz of the University of Paris in France have run computer simulations suggesting that these ridges are made of material swept up from Saturn's rings.