Global Comparative Basin Hypsometric Analysis of Earth and Mars: Implications for Early Mars Climate

•Mars’ basin hypsometry suggests water erosion was likely sourced from precipitation.•Early Martian climate was likely more arid than Earth's hyper-arid regions.•More humid conditions on Mars could have been episodic or short-lived.•Impact cratering preconditioned the surface, affecting subsequent fluvial erosion. While there is a consensus that water played at least some role in the formation of various Martian landforms, including valley networks (VNs), the specific mechanisms and climate conditions are still debated. Basin hypsometric curves, reflecting elevation distributions, offer insights into past processes and climates. Our study presents a global-scale comparison of basin hypsometry on Mars, Earth, the Moon, artificial fractal surfaces, and computer simulated landforms. Results indicate Martian VN formation likely occurred under a climate more arid than hyper-arid Earth, or under more humid periods that were short-lived. Differences in hypsometric attributes between Mars and the Moon suggest VN formation on Mars involved precipitation-driven water flow. Additionally, impact cratering significantly influenced Martian surface conditions, potentially disrupting fluvial erosion processes. This comparative analysis sheds light on the complex interplay of climatic factors and geological processes in Martian landscape evolution.