Named Methone, this small, oval moon was seen in close-up for the first time last year by NASA's Cassini spacecraft. Methone is utterly unlike the other small balls of ice and rock that dot the solar system, which are deeply scarred by impacts. Instead it is smooth, with not a hill or pockmark in sight. Now astronomers may have a clue as to why: Methone is made of lightweight fluff. In fact, this 5-kilometre-wide moon is one of a clutch of space eggs, all orbiting Saturn in the same region between the larger moons Mimas and Enceladus. None of its siblings have been imaged as closely as Methone, but from a distance two - Pallene and Aegaeon - appear to be fairly smooth as well. Read more
It's difficult not to think of an egg when looking at Saturn's moon Methone, seen here during a Cassini flyby of the small moon. The relatively smooth surface adds to the effect created by the oblong shape. Read more
NASA's Cassini spacecraft made its closest approach to Saturn's tiny moon Methone as part of a trajectory that will take it on a close flyby of another of Saturn's moons, Titan. The Titan flyby will put the spacecraft in an orbit around Saturn that is inclined, or tilted, relative to the plane of the planet's equator. The flyby of Methone took place on May 20 at a distance of about 1,900 kilometres. It was Cassini's closest flyby of the 3-kilometer-wide moon. The best previous Cassini images were taken on June 8, 2005, at a distance of about 225,000 kilometres, and they barely resolved this object. Read more