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Viscous Flow Features (VFF) are widespread in the martian mid-latitudes and indicative of near-surface ice deposits. Their distribution and morphology hint at the regional history of ice deposition and ablation, as well as changes in surface temperature. Here we interrogate the deformation history of a type of VFF, a Lobate Debris Apron (LDA), located in the eastern Hellas region, from its surface morphology, discussing the implications it poses for its internal structure and regional climate variability. Our observations integrate data from the Colour and Stereo Surface Imaging System (CaSSIS), the SHAllow RADar (SHARAD), the Context Camera (CTX), the High Resolution Imaging Science Experiment (HiRISE), and the Mars Orbiter Laser Altimeter (MOLA). Morphological observations, spectral analysis of characteristic wavelengths, and ice deformation stability analysis place constraints on the dynamics and deformation history of the deposit. We discuss contrasting hypotheses for the origin of the different surface structures, including the possibility of gelifluction in addition to glacial creep. Our results provide a guide to interpret glacial deformation patterns in martian VFFs in the light of internal structure, regional climate history, and underlying topography. [Display omitted] • Glacial deformation patterns are linked to climate and external forcing. • Mid-latitude martian glacial landscape evolution can hold climate record. • Lobate Debris Aprons (LDA) history from its deformational morphology. [ABSTRACT FROM AUTHOR]

• Most Martian valleys failed to fluvially erode the landscape and reach steady-state. • Rain/snow and evaporation/sublimation dominated Martian drainage basin hydrology. • Six valley networks analyzed, e.g., Naktong and Evros valles, reached steady-state. Valley networks are ancient drainage systems incised on the southern hemisphere of Mars, and stand as evidence that liquid water once sculpted its surface. The duration of valley network activity and the sources of water are key questions in deciphering the timing of water stability on early Mars, but remain poorly constrained. In this study we address two questions: Did Martian valley networks evolve for sufficiently long to establish their own erosional basins, or do their profiles primarily reflect landscape pre-incision topography? And were these valleys precipitation-fed or spring-fed? Our analysis uses the theoretical framework built to describe the shape of steady-state river profiles on Earth to compare and analyze the concavity of 62 valley network longitudinal profiles on Mars. Using non-linear fits to valley profiles we evaluate the degree to which valley networks are consistent with fluvial steady-state. The fit enables the identification of valley network concavity index and area-discharge exponent, which we then interpret in terms of the theoretical framework to discuss valley network maturity and water source. Our results show that the majority of valley networks do not have concave or even smooth profiles, and did not substantially modify their surrounding landscape. We observe disparity in concavity indexes of valley networks belonging in the same integrated basins, indicating different stages of landscape evolution and lack of synchronous valley development. However, our results identify six valley networks consistent with fluvial steady-state and areally uniform precipitation. [ABSTRACT FROM AUTHOR]

The CanMars Mars sample return (MSR) analogue mission was conducted as a field and operational test for the Mars 2020 sample cache rover mission and was the most realistic known MSR rover analogue mission to-date. A rover — similar in scale to that of rover planned for NASA's Mars 2020 mission — was deployed to a scientifically relevant Mars-analogue sedimentary field site with remote mission operations conducted at the University of Western Ontario, Canada; the mission aim was to inform on best practices and optimal approaches for sample acquisition modeled on the Mars 2020 rover mission. The daily operational procedures of the CanMars Science Team were modeled on those of current missions (i.e., Mars Science Laboratory tactical operations), serving as a study of known operational workflows and as a testbed for new approaches. This paper reports on the operational results of CanMars with best-practice recommendations. CanMars was designed as a Mars 2020 mock mission and thus carried similar science objectives; these included (1) advancing the understanding of the habitability potential of a subaqueous sedimentary environment through identifying, characterizing, and caching drilled samples containing high organic carbon (as a proxy for preserved ancient biosignatures) and (2) advancing the understanding of the history of water at the site. The in situ science investigations needed to address these science objectives were guided by the Mars Exploration Program Analysis Group goals. Effective and efficient Science Team operational procedures were developed – and many lessons were documented – through daily tactical planning and science investigations employed to meet the sample acquisition goals. In addition to the documentation of the CanMars operational procedures, this paper provides a brief summary of the science results from CanMars with a focus on recommendations for future analogue missions and planetary sample return flight missions, providing specific value to operational procedures for the Mars 2020 rover mission. • Rover mission operations management, procedures, and workflows were vetted. • We document the complex Science Team interactions relevant to operational workflows. • An intentional operational structure must be employed for optimal use of very limited mission time. [ABSTRACT FROM AUTHOR]