I'd expect the Moon-hole to be basically invisible: it's so small that you'd never see it, even if backlit (0.1 mm == small!) and any accretion-disk like effects would probably be too small to see at any reasonable distance.
On the other hand, this would be an incredible boon to the human race: as I understood it, you could use such a thing to turn matter into energy with about 30% efficiency! Then, just beam it home as microwaves.
(my understanding is that a high-speed particle beam that is shot just close enough to be captured by the hole will spiral in, gaining immense energy as it goes--much of which will be radiated off before it enters the hole. This has the effect of releasing a large percentage of the beam's mass as energy)
Anyway, if it's a tech civilization that's got this, they may have tapped it for power, which probably requires putting a power station around the hole.
Intrope got a reaction from Sociotard in A black hole in orbit: what would it be like?
