ANCIENT MARS RIVERS MAP ENDURING HABITATS
Orbital scans chart 16 immense river networks from 3.7 billion years ago, spanning Early Hesperian, transporting sediments over vast distances with groundwater-fed persistence.
These braided channels, sourcing from aquifers and rains, carved canyons, formed deltas, and layered nutrient-rich deposits fostering chemical evolution.
Hydrology dominated: baseflow from subsurface reservoirs sustained flows, enabling microbial colonization in sediment-water mixes.
Earth-scale but compact, they covered 5% area yet moved 50% sediments, preserving clays and organics in stratified beds.
Models reconstruct discharge rates, with floods pulsing through valleys where biology could leverage dissolved minerals.
This network bridged wet Noachian to dry transitions, maintaining wet corridors amid cooling.
Data integration highlights paleolakes as life cradles, with inverted ridges marking enduring streams.
Optimism soars: these archives hold keys to cosmic biology.
Primary source: Proceedings of the National Academy of Sciences