Valleys on Mars strongly resemble those in arid regions on Earth, suggesting that the Red Planet used to experience long periods of heavy precipitation and erosion, Swiss researchers believe. For years the scientific community has been studying the question of water on Mars. Was it rainwater that caused streams and rivers to swell? Or did ice in the soil melt due to volcanic activity, and seep out to form rivers? A new study now suggests that the branching structure of former river networks on the Red Planet has parallels with terrestrial arid landscapes. This was revealed in a paper published in Science Advances by physicists Hansjörg Seybold and James Kirchner from ETH Zurich’s Institute for Terrestrial Ecosystems, and planetary scientist Edwin Kite from the University of Chicago. Using statistics from all mapped river valleys on Mars, the researchers conclude that the contours still visible today must have been created by surface run-off rainwater. They exclude the ...
