At https://phys.org/print449396404.html … comparison of branching angles on Mars with arid landscapes on Earth show some similarities. Researchers are suggesting narrow channelled networks on Mars are due to heavy rainfall run-off – published in the open science access site Science Advances. This differs from prior explanations as the channels have been interpreted as the remains of what was once a standing body of water. In addtion, other theories include groundwater supping, or leakage, fluvial run-off, and ice melting. The new theory concentrates on the narrow angles – which on Earth are caused by infrequent rainfall. Successive rainfall leads to a deepening of the channels and the same may be true on Mars. Rather than being formed by subtle movements of groundwater they were likely carved into the ground by rushing water. This would suggest Mars once had an active hydrologic cycle.
William got into contact and pointed out that Donald Patten and Samuel Windsor (2003) had predicted that Mars had a brief encounter with ice which changed to water and caused rapid run-off in about a day or so – which is a remarkable coincidence. The article in Science Advances has no imput from Patten and Windsor as far as it is known but the two come to a similar scenario.