Why can't I hold all these planets?

The largest planet, and where all characters find themselves landing when the first arrive is Terra. It starts out approximately a quarter of a mile in diameter, but will get larger as the void becomes more populated. There is a single large river that spirals around the planet, running from north to south. At the north end is a freshwater spring, the source of its waters. Where the river ends there's a saltwater sea, complete with beaches and the occasional palm-like tree.

It is at the moment the only planet with an Earth-like night/day cycle. It is located exactly between the sun and moon, spinning on its axis that there is a 12-hour day, 12-hour night with dawn and dusk in between. Fancy stuff.

Scattered over the surface of the planet are various forms of housing—dirt huts, rickety looking cabins, the occasional town house. None of the buildings are anything approaching luxurious, though not all are run-down. They are, however, only furnished with the bare essentials: a few beds or cots (depending on the type of home), some chairs, a table, at least some kind of shelving or cabinets . . . All very basic, enough to at least keep someone sheltered and rested, but not much more than that.