It seems that the current installment of Unidentified Earth is a stumper! This makes me happy, although it also makes me wish I'd saved this one for a while, because I suspect that most of the remaining ones I have bookmarked -- enough to get us into January at least, at the current rate -- will almost certainly be easier, with a few that I'm sure will be identified almost instantly (the only reason I'll be doing those is basically that they look really cool from space).
So, anyway, I've updated this week's episode with a hint. Have a look. I'll post another hint tomorrow evening as well, just in case the thing is still unidentified!