I'm a Co-Investigator with Mastcam-Z and MEDA (Mars Environmental Dynamics Analyzer) on the Mars 2020 mission, working as a researcher at Cornell University in Ithaca, New York. I've been lucky to work on the Galileo mission to Jupiter, Mars Pathfinder, the twin Mars Exploration Rovers Spirit and Opportunity, and the currently active Mars Science Laboratory rover, Curiosity. Time "Earth-side" has included gaining scientific perspectives from experiments in wind tunnels, and from geologic field work in California, New Mexico, Colorado, Washington, Utah, Scotland, and Iceland.
For the Mars 2020 strategic planning exercise, I've participated in the "Atmosphere" group (while trying to follow the deliberations of several of the other groups, as well). Immediately after landing, everyone on the team will feel the pressure to rapidly compile a comprehensive "cache" of sealed samples representing the most significant materials in the Jezero crater region—high enough in science value to justify return to Earth later by a follow-on mission (a pretty high bar to be striving for). The clock will be ticking loudly in our ears, of course, as soon as the rover's six wheels first touch the martian surface.
As might be guessed, the work of the Atmosphere group has been a little different from the other groups, emphasizing fundamental questions that are relevant across much of the martian surface, not just near the Jezero crater landing area. Examples: How strongly must winds blow in the thin martian atmosphere to raise dust into a dust storm, or to blow sand along the surface to form ripples and dunes seen widely across the martian surface? What combination of Perseverance camera observations combined with wind speed measurements could answer these long-standing questions? In fact, other strategic groups have also been doing their work with an eye toward leveraging Jezero science to address broader-scale fundamental questions about Mars. The science community expects this, and so does the public. This is because our neighboring planet is so hard to get to, is visited so infrequently, and our explorations thus far have been extremely limited, all of which makes our coming time on the surface with Perseverance precious for many reasons.
The "caching" of samples might seem at first glance to be a purely geological task, but this is not so. In the Atmosphere strategic group, one challenge has been to remind the rest of the team that the atmospheric environment and how this interacts with the surface currently, and in the past, affects mission efficiency and affects interpretation of surface materials in several ways. For example, a lesson drawn from previous rover experience at the MER Opportunity landing site is that wind can organize the local surface materials conveniently according to composition, and potentially with essential clues to the past role of water: At Opportunity's Meridiani Planum landing site, wind-related processes had concentrated hematite-enriched aqueous concretions together at ripple crests, where their composition could be measured most effectively. These small concretions had once been scattered sparsely within weaker sedimentary materials, now long eroded away, that previously had been saturated with water. It was these humble, yet resistant concretions, concentrated by the wind at ripple crests, that turned out to be the source of the hematite signature sensed from orbit that drew the Mars Exploration Rover mission to the Meridiani Planum landing site to begin with.
At Jezero crater, a prime target of the Perseverance rover will be materials carried by water that once poured into the crater, forming delta deposits that have since been partly eroded away and re-worked by the wind. What erosionally-resistant materials—perhaps originating from outside Jezero crater—might have been swept onto the crater floor area by a delta-forming river, then reworked by the wind and concentrated for convenient and efficient inspection at the crests of large ripples? Are these possibilities worth inspecting at some point along our traverse? This is one example of the many diverse ideas that the Atmosphere strategic group has been evaluating to increase the effectiveness and value of rover operations after landing.
from The Planetary Society Articles https://ift.tt/3g6iPNL
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