Moon(s) Watcher

I know alot of you out there know me for my space writings, and here I go again. Just in case you forgot what a "Mutual Event" is. When a moon passes in front of or behind another moon it is called a Mutual Event. Have I been out of the loop? or is this a new terminology since Cassini started studying Saturn and its many moons? Being a bit of a space buff I thought I would have heard of this before. I would venture to say outside the Saturn System the event would be quite rare, as you need more than one moon to have this take place. I think the last count of moons Saturn has is up around 70, a mere 64 known before Cassini.  Well just thought I would pass that along so the conversation at the water fountain tomorrow morning won't be so dull.