"Intermittent Flow of Water in Martian Valleys Lasted for Centuries, Study Suggests"
Research suggests that Martian valley networks were formed over hundreds of millions of years, with intermittent flow events, based on the dating of impact craters. This challenges the previous understanding of early Mars as either "warm and wet" or "cold and icy," indicating that conditions permitting surface water likely varied considerably. The slow erosion rate of Mars' rivers is comparable to parts of the Atacama Desert in Chile, and the intermittent flow may have been influenced by factors such as volcanic activity or variations in the planet's axial tilt and orbit around the sun.