Umbra

This is a world of perpetual darkness. A planet formed under the influence of a Red Dwarf, composed mostly by silicate rock and geologically-heated lakes of ammonia; with a dense atmosphere of nitrogen and oxygen.   Temperatures are freezing, away from the cracks that leak geothermal energy, and conditions on the planet are actively hostile to life. Yet, near these cracks, safe havens have been formed. Unknown precursors left huge terraforming structures that actively drain energy and resources from the planet's iron core, in order to maintain an artificially created habitat. An ferrous compound dust is suspended on the sky at a radius around the structure, and an electric charge is injected to it to produce a magnetic field around the area, to protect it from the massive solar flares that its star produces. Said compound absorbs sunlight very efficiently, and releases heat to its lower habitat contributing to a greenhouse effect of sorts.   Since sunlight is almost non existent under these ferrous domes, lifeforms obtain their energy from a ground-injected substrate generated as a side-product by the alien facilities. Therefore, plants do not photosynthesize to create their sustenance; instead, they extract the rich substrate from the ground and store it diluted in evolved sacs suspended above ground for later consumption.   Overall, it is a very alien world.