posted on Jul, 7 2004 @ 02:54 AM
You are correct, no moons are known to have moons of their own.
At least as far as we know. It's not really impossible, but gravitational interactions prevent it from happening long term.
I'm willing to bet, that it happens from time-to time, and we just miss it,
the little moon is ejected from orbit, and is on it's own again..
On a technicality, you could the mention Pluto/Charon combo.
They kinda orbit each other, Charon being so big, relative to Pluto.
As Far as the Asteroid IDA is concerned, I remember that someone in NASA
,I think, wanted to name it's tiny little moon, BESIDA...LOL