Saturn’s rings reveal how to make a moon

Disturbances in the icy rings of Saturn have given scientists an insight into how moons are made. Writing in the journal Icarus this week, Professor Carl Murray from Queen Mary's Astronomy Unit reports that recently discovered disturbances at the very edge of Saturn's outer bright A ring result from a small icy object that formed within the ring and which may be in the process of migrating out of it. They have nicknamed the object, 'Peggy'. "We hadn't seen anything like this before," explained Professor Murray. "We may be looking at the act of birth, where this object is just leaving the rings and heading off to be a moon in its own right," he said. Saturn's rings are a small-scale version of discs of ice and dust that surround young stars. One reason for high interest in how moons form in Saturn's rings is insight into how Earth and other planets may have formed and migrated within a disc around our star, the sun.