Outcrop-Scale Hyperspectral Studies of a Lacustrine-Volcanic Mars Analog: Examination with a Mars 2020-like Instrument Suite

Abstract:

Using the recently developed Ultra Compact Imaging Spectrometer (UCIS) (0.4-2.5 µm) to generate outcrop-scale infrared images and compositional maps, a Mars-relevant field site near China Ranch in the Mojave Desert has been surveyed and sampled to analyze the synergies between instruments in the Mars 2020 rover instrument suite. The site is broadly comprised of large lacustrine gypsum beds with fine-grained gypsiferous mudstones and interbedded volcanic ashes deposited in the Pleistocene, with a carbonate unit atop the outcrop. Alteration products such as clays and iron oxides are pervasive throughout the sequence. Mineralogical mapping of the outcrop was performed using UCIS. As the 2020 rover will have an onboard multispectral camera and IR point spectrometer, Mastcam-Z and SuperCam, this process of spectral analysis leading to the selection of sites for more detailed investigation is similar to the process by which samples will be selected for increased scrutiny during the 2020 mission. The infrared image is resampled (spatially and spectrally) to the resolutions of Mastcam-Z and SuperCam to simulate data from the Mars 2020 rover. Hand samples were gathered in the field (guided by the prior infrared compositional mapping), capturing samples of spectral and mineralogical variance in the scene. After collection, a limited number of specimens were chosen for more detailed analysis. The hand samples are currently being analyzed using JPL prototypes of the Mars 2020 arm-mounted contact instruments, specifically PIXL (Planetary Instrument for X-ray Lithochemistry) and SHERLOC (Scanning Habitable Environments with Raman & Luminescence). The geologic story as told by the Mars 2020 instrument data will be analyzed and compared to the full suite of data collected by hyperspectral imaging and terrestrial techniques (e.g. XRD) applied to the collected hand samples. This work will shed light on the potential uses and synergies of the Mars 2020 instrument suite, especially with regards to spectral (i.e. remote) recognition of important and interesting samples on which to do contact science.