Board Thread:Fiction Universe Discussion/@comment-9141454-20150625191138/@comment-9141454-20150626134734

Also, another method would use nanobots just to extract minerals. It would work like a grey goo, getting to a planet and then slowly consuming it making even more nanobots for an avalanche effect, thus if this method should be used with controlled manner, then we shouldn't let these machines fly off. Who knows what could these do.

So on, these nanobots slowly consuming planets would extract minerals, make even more copies of themselves increasing time of resource gathering.

So, if we'd have life-less planet with size of about mercury, assume that one nanobot can process 1g of matter in about 12h (nanodissamblers), that nanobot weights 0.00001g and creates it's copy every second (n^2), it would take...

Well, not much time.