Final Report of the Mars Sample Return Science Planning Group 2 (MSPG2)

Abstract

This paper was written by the MSR Science Planning Group 2 (MSPG2) working under a Terms of Reference from NASA and ESA.

In Situ Identification of Paleoarchean Biosignatures Using Colocated Perseverance Rover Analyses: Perspectives for In Situ Mars Science and Sample Return

“…It is probable that samples hosting putative biosignatures will be known long prior to their return to Earth, during which time an appropriate analytical protocol can be developed ( cf . Rummel and Kminek, 2018 ; Kminek et al, 2022 ; Meyer et al, 2022 ), likely on a sample-by-sample basis. A wide range of returned sample science could be proposed further to in situ analyses conducted by Perseverance in order to confirm or disprove their potential biogenic nature.…”

“…Such studies also provide initial guidance for sample return. At present, preparations for MSR are being formulated and refined with emphasis on analytical strategies, curation and sample storage, and planetary protection (Rummel and Kminek, 2018 ; Smith et al, 2021 ; Kminek et al, 2022 ; Meyer et al, 2022 ; Tait et al, 2022 ). Defining the datasets to which we will have access from only in situ rover analyses will facilitate the prioritization of analyses conducted on returned materials and could conceivably incentivize the development of instrumentation or analytical approaches enabling missing data to be acquired.…”

“…In this regard, the NASA Mars 2020 Perseverance rover mission has as its principal objectives the reconstruction of Noachian–Hesperian paleoenvironments at an ancient martian locality, Jezero crater (Isidis Planitia), and the potential identification of fossil traces of life (biosignatures) in sedimentary strata therein (Williford et al, 2018 ; Farley et al, 2020 ). Through sampling and caching a diverse suite of geological samples within hermetically sealed tubes, Mars 2020 also represents the first step toward near-future international collaborations on Mars Sample Return (MSR) (Farley et al, 2020 ; Grady, 2020 ; Meyer et al, 2022 ). Potential organic- and biosignature-bearing sedimentary rocks are high-priority targets for MSR since they may answer major outstanding questions in astrobiology, including (i) the nature of habitable niches early in Mars' history; (ii) whether biosignatures and/or (pre)biotic organic materials are preserved on Mars; and (iii) if life emerged on Mars, for how long the biosphere persisted (Grotzinger et al, 2014 ; Herd et al, 2021 ).…”

Samples Collected From the Floor of Jezero Crater With the Mars 2020 Perseverance Rover

“…Remote sensing and in situ science conducted by the Mars 2020 Perseverance rover show that the rocks exposed at the floor of Jezero Crater are in fact igneous, but have distinct formation histories (Bell et al, 2022;Farley et al, 2022;Liu et al, 2022;Scheller et al, 2022;Tice et al, 2022;Wiens et al, 2022). Hypotheses related to the origin of Mars and the evolution of its interior and surface motivated by both meteorite and Mars mission work will be further tested by Earth-based analyses of rock samples collected by Perseverance following MSR (Kminek et al, 2022;Meyer et al, 2022). As presented below and detailed in supporting studies contained in this special volume, the analyses conducted by Perseverance, particularly on abrasion sites, show that the bedrock units in Jezero are igneous in origin.…”

“…The Mars 2020 mission is the first step in a multi‐stage international effort towards Mars Sample Return (MSR), which has been a high priority of the international planetary science community for decades (e.g., Kminek et al., 2022; Meyer et al., 2022). While several different approaches to MSR have been considered in the past, the National Research Council (2011) Vision and Voyages for Planetary Science in the Decade 2013–2022 recommended the collection of well‐documented samples from a selected site on Mars by a rover capable of mineralogic and geochemical characterization.…”