I had a go last night and the night before as it was very clear where i live, i took some shots at dusk as the moon isn't too bright and got some reasonable images.
The problem i have is that the longest lense i have is a 100mm-300mm and you get too much softening at its maximum focal setting so although they looked ok, the definition just wasn't there.
I'm going to try adding a teleconverter and see if that helps as i can't justify splashing out lots of money on big lenses i'll never use.