The valley and alluvial fan provide evidence for geologically recent (Amazonian-aged) fluvial activity[2][3] and sustained water flow[4] on Mars.

Recent high-resolution orbital images of Peace Vallis and its watershed also suggest that at least one glacial episode affected Gale crater.

[7] The valley is centered at 4°13′S 137°14′E / 4.21°S 137.23°E / -4.21; 137.23[1] in the northeastern Aeolis quadrangle of Mars and drains approximately 1,500 square kilometers (580 sq mi) of the northern rim of Gale Crater.

[9] The northern rim of Gale Crater is heavily eroded and hosts a number of geomorphic features indicating the effects of flowing water.

[12] Others have suggested they were produced by mass wasting,[13] spring sapping,[14] or from snowmelt[15] on an ancient Mars whose climate was dry and cold much like today's.

[16] Erosion of the watershed surface has produced a mottled scoured appearance, suggesting mobilization and transport of sediments into topographic lows.

Compared with most terrestrial valleys carved by rainfall, the drainage density (stream length per unit area) of Peace Vallis and its tributaries is very low.

[18] Factors that control drainage density include slope, rock type (which determines infiltration capacity)[19] and climate (mainly precipitation).