Potential traces of life preserved in a geological analog of Mars

By Julie Hartz - Crew Commander and Geologist


The research I intend to carry out as crew geologist involves field exploration and astrobiology. The future manned missions to Mars will have as major objective the assessment of the current and/or past habitability of the surface of Mars. Therefore crew geologists, supported by rovers, will have to sample the surrounding geologic “terrains” according to their physical and instruments' limitations. During my time at the MDRS, I intend to collect several sets of rock and regolith samples during well-planned Extra Vehicular Activities (EVAs) in order to adress two main questions:

(1) What kind of traces of life (i.e. biosignatures) may be found in a geologic analogue of Mars?
Biosignatures may be of textural (e.g., macro- and micro-fossils), mineralogical (some minerals only form in the presence of life), or chemical nature (e.g., complex organic molecules, isotopic fractionation etc...).

(2) What sample collection configuration allows for the highest-fidelity reconstruction of the local stratigraphy?
NASA's Perseverance rover sampling system is designed to collect between 30 and 40 ~15g samples of rock and regolith. I wish to compare this sampling configuration to others that would include fewer but bigger samples (i.e. with more sample material) and assess which configuration enables the best reconstruction of the local stratigraphy.

The methods may include field exploration techniques (e.g., aerial imaging, field reconnaissance through EVAs), field observations (e.g., stratigraphic logging, macro- descriptions, hand-lens-based mineralogy), sampling methods (e.g., hammers, scoops, aluminium foil/zip bags), sample analyses in the Science Dome (e.g., micro-descriptions with microscopes, micro-scale stratigraphic logging, paleoenvironment assessment), and results processing (e.g., comparison of logs with available data/literature, statistical analysis of representativity/heterogeneity).

As research outcomes I expect to :
(i) identify the best fitted sample configuration for stratigraphic reconstruction,
(ii) build a “catalogue” of potential biosignatures that can be identified in a Martian analogue using an on-field astrobiological protocol, and
(iii) provide insights into potential design improvements of Martian rovers.


For any questions or enquiries about this project, please contact Julie directly at julie.hartz@womars.org