27 standard hours
724 standard days
Surface pressure: 15,8 kPa
Ceryl was the fourth planet orbiting the system's main star - Graem. Out of the inner terrestrial worlds, it was the biggest and the only one that was host to life. It possessed two rather small natural satellites.
While subject to scientific expeditions and mining operations, Ceryl was never inhabited by colonists due to its unfriendly conditions.
The planet's surface was differentiated, mostly consisting of rocky barrens of various elevation and vast, dark deserts. Numerous canyons and mountain ranges existed, formed by the slow, protracted tectonic movements. Together with tidal friction caused by the two moons, they also caused the formation of cryovolcanoes, which erupted volatiles such as liquid ammonia and vapour methane.
Water appeared in the form of relatively small, solid glaciers. The only stable liquid bodies were mainly the ammoniacal lakes and rivers. Local lifeforms were known to thrive in their proximity.
Erosion, caused by manifold factors, formed extensive network of underground caverns.
The planet possessed weak magnetosphere, that nevertheless allowed it to maintain its somewhat thin atmosphere. It was mostly composed of nitrogen, though with a significant amount of methane, which was partially responsible for the atmosphere's navy blue colouration. Other gases included hydrogen and ammonia, like methane coming from the cryovolcanic activity, and traces of various others. Constant, yet feeble haze blurred its dark sky.
Ceryl was a mild example of a "super rotator": its atmosphere rotated faster than the planet itself. As a result, strong winds incessantly lashed its surface, sculpting the characteristic rocky pillars and strengthening the erosion that formed the dark, dusty plains.
Ceryl's seasons resembled in nature those present on the habitable planets of the Confederacy, though due to its distance from the system's sun they were about twice of their length. The temperatures ranged from circa -110°C during the polar winters to around -20°C in the equatorial summer.
Perpetual dust storms occured on the planet, varying greatly in their scale. The biggest ones regularly took place when Ceryl was in its closest position to Graem. Also, liquid ammonia rains were known to happen infrequently, originating from the faint but vast noctilucent clouds.
Even though the conditions of Ceryl were extreme when compared to the ones that usually were hospitable to life, it still possessed quite an affluent ecosystem. However, most of the living organisms were extremophile prokaryotes and simple multi-cellular life forms indigenous to the ammoniacal lakes.
Nonetheless, some more advanced species inhabited the spacious deserts of the planet. Massive and stocky rock-eaters, reaching up to 4 metres in length, roamed the mineral-rich plains, nourishing on its rocks. Another species, the predatory stalkers, dwelt in the numerous underground caverns that formed immense labirynths under the world's surface. The space-faring gliders sometimes visited Ceryl, seeking nutrition in its atmosphere.