The Notional Plan for Sample Collections by the Perseverance Rover for
Mars Sample Return
Abstract
The NASA Mars 2020 Perseverance rover mission will collect a suite of
scientifically compelling samples for return to Earth. On the basis of
orbital data, the Mars 2020 science team* identified two notional sample
caches to study (1) the geology of Jezero crater, collected during the
prime mission and (2) the ancient crust outside of Jezero crater,
collected during a possible extended mission. Jezero crater geology
consists of well-preserved, Early Hesperian to Late Noachian deltaic and
lacustrine deposits sourced from a river system that drained Noachian
terrain. The crater floor comprises at least two distinct units of
sedimentary or volcanic origin whose relationship to the deltaic
deposits is presently unclear. Remotely-sensed data reveal signatures of
carbonate+olivine and clay minerals within crater floor and crater
margin units. Samples from within Jezero that comprise the prime mission
notional sample collection thus include: crater floor units; fine- and
coarse-grained delta facies, the former with potential to preserve
organic matter and/or biosignatures, the latter to possibly constrain
the type and timing of sediment deposition; chemical sediments with the
potential to preserve biosignatures; a sample of crater rim bedrock; and
at least one sample of regolith. The region of southern Nili Planum,
directly outside the western rim of Jezero crater, is geologically
distinct from Jezero crater and contains diverse Early or even
Pre-Noachian lithologies, that may contain records of early planetary
differentiation, magnetism, paleoclimate and habitability. The notional
sample collection from this region will include: layered and other
basement rocks; megabreccias, which may represent blocks of
(pre-)Noachian crust; basement-hosted hydrothermal fracture fill;
olivine+carbonate rocks that are regionally significant and may be
related to units within Jezero crater; and mafic cap unit rocks. The
samples described are notional and may change with ongoing surface
investigations. However, the samples we anticipate collecting align well
with community priorities for Mars exploration, addressing geologic
diversity, potential ancient biologic activity on Mars, planetary
evolution, volatiles, and human health hazards. *Many other Mars 2020
team members were involved in this planning