Overview

• A peer‑reviewed Nature study reports organic carbon alongside submillimetre nodules of iron‑phosphate (vivianite) and iron‑sulfide (greigite) in a Bright Angel mudstone.
• The features were measured in situ with Perseverance’s SHERLOC and PIXL instruments, which the team says cannot by themselves distinguish biological from abiotic origins.
• Scientists describe the assemblage as a potential biosignature compatible with ancient microbial processes, while emphasizing that non‑biological pathways remain possible.
• The sample, nicknamed Sapphire Canyon, was cored at the Cheyava Falls outcrop in Neretva Vallis and remains sealed on Mars for possible return.
• NASA acknowledges that a conclusive test requires Mars Sample Return, a program now delayed and re‑scoped after cost growth to roughly $11 billion and schedule slippage into later decades.