P057-06
Subsurface Water Ice Mapping (SWIM) on Mars to Characterize In Situ Resources
Monday, 14 December 2020: 07:20
Virtual
Nathaniel E Putzig1, Gareth A Morgan2, Zachary Mason Bain1, David M. H. Baker3, Ali M Bramson4,5, Samuel Weston Courville1, Colin M Dundas6, Rachael Hoover7, Stefano Nerozzi4, Asmin Pathare8, Matthew Robert Perry1, Eric Petersen4,9, Hanna G Sizemore10, Bruce A Campbell11, Marco Mastrogiuseppe12, Michael T Mellon13 and Isaac B Smith1,14, (1)Planetary Science Institute, Lakewood, CO, United States, (2)Planetary Science Institute, Washington, DC, United States, (3)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (4)University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ, United States, (5)Purdue University, West Lafayette, IN, United States, (6)U. S. Geological Survey, Flagstaff, AZ, United States, (7)Southwest Research Institute, Boulder, CO, United States, (8)Planetary Science Institute, Pasadena, CA, United States, (9)University of Alaska Fairbanks, Fairbanks, AZ, United States, (10)Planetary Science Institute, Marlinton, WV, United States, (11)Smithsonian National Air and Space Museum, Washington, DC, United States, (12)Università La Sapienza, Dipartimento di Ingegneria dell’Informazione, Rome, Italy, (13)Cornell University, Ithaca, United States, (14)York University, Toronto, ON, Canada
Abstract:
As part of a NASA effort to assess in situ resources for future human missions to Mars, the SWIM Team is performing multi-dataset mapping to characterize the distribution of buried water ice from 60ºS to 60ºN. Deriving composite measures for the presence of accessible ice (upper few meters) from a diverse range of remote sensing techniques with unique resolutions and caveats is a challenging problem. To enable data synthesis, we present a methodology based on “ice consistency” mapping. In 2019, we produced ice consistency maps for much of the northern hemisphere [Morgan et al., in rev., Nature Astronomy]. In 2020, we are extending our mapping to encompass all areas equatorward of 60º latitude at elevations < +1 km (see figure). Our maps are being made available on the SWIM Project website (https://swim.psi.edu), and we intend to complete our extended mapping in the summer of 2020. For AGU, we will present final results for this effort.
The SWIM Project uses multiple datasets: neutron-detected hydrogen (MONS), thermal behavior (TES/THEMIS/MCS), multiscale geomorphology (HiRISE/CTX/MOLA), and surface and subsurface radar echoes (SHARAD). With methods attuned to each dataset, we assign values scaled between +1 (dataset fully consistent with ice) and -1 (dataset fully consistent with the absence of ice). Faced with diverse sensing depths and footprints for these datasets, we are pursuing an optimal approach to formulating a SWIM equation [ibid.] to best represent multi-dataset ice consistency. We are considering weighting factors tuned to the zones of interest as well as Bayesian statistical approaches, with the ultimate goal of constraining ice presence and concentration over a range of depths. As expected from prior work, we are finding that the highest ice-consistency values occur poleward of ~40º latitude. However, in some areas, positive values extend well into the ~20º–30º latitude zone, which is preferable for landing sites due to engineering considerations.
The figure shows the SWIM study area, with interim (July 2020) results of the geomorphology component of our mapping work (darker blue for higher normalized counts of ice-related features). Blockier areas in the north reflect coarser mapping due to limited time available for this work in the 2019 study. Elevations above +1 km (black) are excluded from the ongoing efforts. Hillshade and topography derived from MOLA data.
The SWIM Project is supported by NASA via subcontracts with the Jet Propulsion Laboratory. We thank SeisWare for academic licensing of their Geophysics software.
