Oh yea, and drop that whole "all the planets orbiting one sun" nonsense since it isn't workable. Miranda would have been frozen ice-ball _or_ the "inner planets" would be molten slag.
It was their way dealing with the issue of no FTL travel. And a rather good one at that. Partly terraformed planets led to the many barren landscapes they visited, and they could get to another planet/moon within a reasonable amount of time (ie, before they run out of food and water).
Once it hits the fan, the only rational choice is to sweep it up, package it, and sell it as fertilizer.