SAMPLING POTENTIAL BIOSIGNATURES WITH THE MARS 2020 PERSEVERANCE ROVER

One of the primary goals of NASA's Mars 2020 mission is to search for signs of ancient life in Jezero crater on Mars. The mission aims to address the questions: What habitable niches existed here, when did they exist, and are biosignatures preserved? Jezero crater is an ancient delta-lake system that is a uniquely interesting site for astrobiological investigation due to strong evidence of both clays and carbonates. The Perseverance rover is using a diverse instrument payload to study the geology and potential astrobiology of Jezero crater, as well as a novel sampling and caching subsystem to collect a suite of scientifically compelling samples for return to Earth.

The Mars 2020 science team has identified a prime mission plan and notional cache, based on orbital data and refined by surface observations, to study Jezero crater. Although Perseverance may study the region outside the crater during an extended mission, this presentation focuses on the campaigns within the crater. Analyses will be performed on the Late Noachian to Early Hesperian crater floor, rim, delta, marginal deposits, and regolith. Of particular interest are materials deposited under past habitable conditions with high biosignature preservation potential. These include siliciclastic rocks from the delta, possible chemical sediments (e.g., carbonates, halite, gypsum) from the marginal deposits and crater floor, and possible hydrothermally-altered mafic deposits of the crater floor and basement rocks on the crater rim.

These units will be explored for biosignatures that may be detectable in situ on Mars, including organic compounds (using SHERLOC), morphological biosignatures such as biogenic sedimentary textures (using Mastcam-Z, SuperCam, and WATSON cameras), and biogenic mineral and elemental distributions (using SHERLOC and PIXL). Cached samples to be returned to Earth would, however, be studied in greater detail in laboratories. Such analyses would enable the potential detection of biosignatures such as, but not limited to, specific organic compounds, stable isotope compositions, distribution and compositions of trace and redox active elements, and fine morphological biosignatures.

Acknowledgement: Much of the planning described was performed by the entire Mars 2020 science and engineering teams.