Gemini

Gemini is a rocky, terrestrial planet within the Olympus Star System. It is the second closest planet to the sun, and is the only planet within Olympus Star System to exist within the habitable zone. The landmass of the planet consists of a number of smaller continents and island chains, with water covering about 85% of the surface. Gemini is tidally locked with Olympus Star System, causing one side of the planet to be in perpetual day, while the other is consumed by an ever-freezing night.
Less than half the continents on the planet are near the light dark equator, a slim habitable zone where temperatures are moderate enough to survive without high tech specialized equipment. A number of both native and alien Races call this planet home. Strange magnetic/radioactive phenomena, likely related to the strange ejections from Olympus Star System, bombard the planet nearly constantly, causing massive rolling lightning storms and other strange weather effects.
Evidence discovered in the UEF's initial scans and exploration of the planet indicate that there are elements both within and on the surface that suggest an artificial origin, and likely not crafted by the local native populations, as they were still in primitive or early industrial phases when the UEF arrived in 2907. This suspicion was made reality when the Dark Tower was explored and a hostile AI was unleashed on the continent of Ayr, signalling the begining of the end for UEF dominance on Gemini and eventually leading to the Great Exodus.