Perpetuum

For a planet to be colonized, it has to support liquid water. And when that planet is orbiting a red dwarf star which gives off a fraction of Sol's heat, it has to be so close to maintain that temperature that it becomes tidally locked, plunging one half of the world into eternal daylight and the other into perpetual night. Perpetuum is one such planet, and despite the drawbacks of not having a day-night cycle, it has done quite well for itself as a tourist resort.

The planet's daylight side has a flourishing ecosystem of exotic alien life which thrive in the sunlight, most of which resemble Earth flora. This makes nature safaris a profitable attraction for the planet, but permanent settlement on this side is risky to impossible: with no axial spin, the planet's magnetosphere is dangerously weak, and solar flares from the local star deliver bursts of dangerous radiation to the planet's surface. The local life has evolved to cope, but human tourists are advised to keep their hands and arms inside the radiation-shielded safari vehicles.

Though the freezing temperatures of the night side prevented any native life from taking hold, human colonization has filled the gap where no other life form was fit to survive. Just far enough under the shadow of the planetary horizon to protect them from solar flares without freezing, small metropolises like Casino City cater to every demand of the hordes of wealthy vacationers. Luxury hotel towers stretch towards skies steeped in endless twilight, and never-ending night means a never-ending night life between the myriad clubs and bars lining the streets.

A temperate belt exists around the planet’s prime meridian, which is subject to frequent storms. MagLev rail lines ferry vacationers across it from cities to safari zones around the clock, because on Perpetuum, as local sayings go, “no two people go to bed at the same time.”