Perseverance’s radar revealed ancient subsurface river delta on Mars
Summary
NASA’s Perseverance rover using the RIMFAX radar detected a likely older, buried river delta beneath Jezero Crater’s Margin unit, suggesting a second delta from Mars’ Noachian era. The radar reveals layered, delta-like structures and deep soundings, pointing to long-lived, ancient aqueous conditions that could host biosignatures at depth. While the data favor a fluvial, deltaic origin, scientists acknowledge alternative explanations such as volcanic or shoreline processes and anticipate further data to refine the interpretation.