This episode explores Channels, deltas, minerals and sedimentary structures that record past flowing water. The story keeps the mechanisms clear and the research grounded for a casual listener. Inside this episode: - Shapes seen from orbit - When a river enters a lake - Layers as a flow record - Stones shaped by transport - Minerals that remember water Sources include NASA Science, delta-like fan and persistent rivers, NASA Mars 2020 mission, and NASA Perseverance science highlights. This episode is a researched narrative summary. Historical records may be incomplete, translated differently, or interpreted differently by scholars. We distinguish documented facts, estimates, disputed interpretations, and later stories where material. Corrections are logged and incorporated into future editions. Follow Solar System Field Notes for more researched ...