Overview

• The Journal of Geophysical Research: Planets study catalogs three distinct water–rock interaction phases in Jezero Crater from localized high-temperature acidity to neutral and then low-temperature alkaline fluids.
• Minerals such as greenalite, hisingerite and ferroaluminoceladonite mark the earliest harsh conditions, while widespread sepiolite indicates later, more favorable alkaline environments across rover-explored units.
• Researchers applied the MIST uncertainty-propagation approach to PIXL X-ray data, assigning confidence levels to each mineral identification and building a mineralogical archive to guide sampling priorities.
• The findings provide context for a separate Nature report on a Bright Angel core with organics and iron-rich microtextures that could be biological or abiotic, with confirmation requiring Earth-based tests.
• Perseverance has collected 30 samples with a backup depot on the surface, yet definitive analyses await a sample-return plan now delayed into the 2040s as NASA reviews cost and schedule options.