Hi JJJ;
They're terrific aren't they ?
It's either a giant spud or a dumbbell floating in space !

Beats me what that smooth bit in the middle is !! Looks like a completely different texture when compared with the end bits. Looks like two halves joined together !
We need some comet experts to talk about this !!
Thanks for the post (Liz and I are 'rapping' on her thread, in the 'Observations' forum, also).
Cheers & Rgds