Has anyone calculated how large a moon Mars needs in order to get decent oceans?

Anyway, IIRC, even the bright surfaces of the moon have a low albedo. Maybe Mercury would do, or perhaps we could grab an iron-nickle asteroid and forge a lot of little polished-steel satellites. If we could toss in some gold-coated ones as well, that would be even better.

Now all we need to do is come up with a good technological excuse to put millions of dust-sized to house-sized spheres in bands less than a kilometer thick. That will help with the grant money, and mollify the orbital tower fans.