Editing Necron Red II (section)

==Hydrology==
Liquid water cannot exist on the surface of Necron Red II with its present low atmospheric pressure, except at the lowest elevations for short periods but water ice is in no short supply, with two polar ice caps made largely of ice. The volume of water ice in the south polar ice cap, if melted, would be sufficient to cover the entire planetary surface to a depth of 11 meters. Additionally, an ice permafrost mantle stretches down from the pole to latitudes of about 60°.

Much larger quantities of water are thought to be trapped underneath Necron Red II's thick cryosphere, only to be released when the crust is cracked through volcanic action. The largest such release of liquid water is thought to have occurred when the Nay'hana Abyss formed early in Necron Red II's history, enough water was released to form the massive outflow channels. A smaller but more recent event of the same kind may have occurred when the Cerberus Fossae chasm opened about 5 million years ago, leaving a supposed sea of frozen ice. However, the morphology of this region is more consistent with the ponding of lava flows causing a superficial similarity to ice flows. These lava flows probably draped the terrain established by earlier catastrophic floods of the Athabasca Abyss. Significantly rough surface texture at decimeter (dm) scales, thermal inertia comparable to that of the Gusev plains, and hydrovolcanic cones are consistent with the lava flow hypothesis. Furthermore, the stoichiometric mass fraction of H2O in this area to tens of centimeter depths is only ~4%, easily attributable to hydrated minerals and inconsistent with the presence of near-surface ice.

More recently detailed surveys on the Necron Red II give much more detail about the history of liquid water on the surface of Necron Red II. Despite the many giant flood channels and associated tree-like network of tributaries found on Necron Red II there are no smaller scale structures that would indicate the origin of the flood waters. It has been suggested that weathering processes have denuded these, indicating the river valleys are old features. Higher resolution observations from spacecraft also revealed at least a few hundred features along crater and canyon walls that appear similar to terrestrial seepage gullies. The gullies tend to be in the highlands of the southern hemisphere and to face the Equator; all are poleward of 30° latitude. The researchers found no partially degraded (i.e. weathered) gullies and no superimposed impact craters, indicating that these are very young features.

In a particularly striking example surveys performed six years apart, show a gully on Necron Red II with what appears to be new deposits of sediment. It is argued that only the flow of material with a high liquid water content could produce such a debris pattern and coloring. Whether the water results from precipitation, underground or another source remains an open question. However, alternative scenarios have been suggested, including the possibility of the deposits being caused by carbon dioxide frost or by the movement of dust on the planet's surface.

Further evidence that liquid water once existed on the surface of Necron Red II comes from the detection of specific minerals such as [[hematite]] and goethite, both of which sometimes form in the presence of water.

Nevertheless, some of the evidence believed to indicate ancient water basins and flows has been negated by higher resolution studies taken at resolution about 30 cm by Federation Survey Teams.