Astrobiological Potential of Rocks Acquired by the Perseverance Rover at a Sedimentary Fan Front in Jezero Crater, Mars
Tanja Bosak · David L. Shuster · Eva L. Scheller · Sandra Siljestrom · Megan J. Zawaski · Lucia Mandon
AGU Advances · 2024
Of seven Perseverance sedimentary core samples from Jezero Crater's fan front, a sulfate-bearing mudstone ranks highest for biosignature preservation potential, providing the scientific basis for Mars Sample Return cache prioritization.
Brief
Bosak et al. (2024) evaluated the astrobiological potential of seven sedimentary rock samples drilled by the Perseverance rover at the Jezero Crater delta front, a site interpreted as a preserved ancient lake margin. The assessment weighted multiple factors, aqueous alteration history, organic matter preservation window, mineralogy, and post-depositional thermal and radiation exposure, against each sample's lithological and geochemical character. The sulfate-bearing mudstone emerged as the highest-priority sample, as sulfate minerals are known to encapsulate and shield organic molecules from oxidation and radiolytic degradation over geologic timescales. The paper explicitly frames its conclusions as scientific justification for sample-return cache prioritization, linking field-scale petrology to Mars Sample Return mission architecture.
Metadata
- Category
- Search
- Venue
- AGU Advances
- Type
- Peer-reviewed
- Year
- 2024
- Authors
- Tanja Bosak, David L. Shuster, Eva L. Scheller, Sandra Siljestrom, Megan J. Zawaski, Lucia Mandon
- Access
- Open access
- Programs
- Mars Sample Return, Mars 2020 Perseverance Mission
- Instruments
- Perseverance rover drill, SHERLOC (Raman/fluorescence spectrometer), PIXL (X-ray lithochemistry), Mastcam-Z
- Data sources
- Perseverance rover core sample data, Jezero Crater delta front drill cores
- Tags
- astrobiology, biosignature, Mars, Mars Sample Return, sedimentary geology, planetary science
Key points
- Seven sedimentary rock samples collected at the Jezero fan front were systematically evaluated for biosignature preservation potential using a multi-factor astrobiological framework.
- The sulfate-bearing mudstone was identified as the highest-priority sample, outranking six other lithologies on criteria including aqueous history, organic preservation window, and mineralogical shielding capacity.
- Sulfate minerals are highlighted as particularly effective biosignature hosts because they can encapsulate organic compounds and limit exposure to oxidants and ionizing radiation over billion-year timescales.
- The Jezero delta front was targeted precisely because it aggregates detrital material transported from geochemically diverse source terrains across the Jezero watershed, broadening the potential sample provenance.
- The paper serves as explicit scientific justification for Mars Sample Return mission planners in deciding which cached cores to prioritize for Earth return, directly linking geologic assessment to mission resource allocation.
- Post-depositional overprinting, including thermal history and cumulative radiation dose, was treated as a negative factor that could degrade original biosignature fidelity regardless of initial preservation conditions.
Most interesting
- Among seven sedimentary samples from what is arguably the best-preserved ancient lake-margin deposit on Mars, only one, the sulfate-bearing mudstone, achieved the highest biosignature preservation rating, illustrating that sedimentary origin alone does not confer high astrobiological priority.
- Sulfate encapsulation of organics is so effective that terrestrial analogs (e.g., evaporitic gypsum) have preserved microbial biomass for tens of millions of years; the Mars samples would need that process to have operated across more than three billion years.
- The Jezero fan front samples represent material originally eroded from ancient Noachian terrains and transported by a fluvial system into the crater lake, meaning a single core can carry geochemical signals from source regions Perseverance will never visit.
- Mars Sample Return, which this paper directly informs, would be the first mission to return scientifically selected geological samples from another planet, with Earth-based detection limits orders of magnitude below anything achievable by in situ rover instruments.
- The authors include both geobiologists (Bosak) and geochronologists (Shuster), reflecting that biosignature potential assessment requires simultaneous evaluation of biological preservation and the absolute timing of aqueous environments.
- AGU Advances, the venue, uses open-access rapid publication with post-acceptance peer review transparency, the editorial handling timeline for this paper spans the same period as Perseverance's active delta-front campaign, suggesting real-time mission-science feedback loops.