SOPHIA: A mineralogical simulant for phyllosilicate terrains at the Rosalind Franklin landing site, Oxia Planum, Mars

Abstract

The phyllosilicate-bearing martian plain, Oxia Planum, is the proposed landing site for the Rosalind Franklin rover mission, scheduled to launch in 2028. Rosalind Franklin which will search for signs of past or present life on Mars. Terrestrial analogue sites and simulants can be used to test instruments analogous to those on Rosalind Franklin, however no simulant for Oxia Planum currently exists. In anticipation of this mission, a simulant - SOPHIA (Simulant for Oxia Planum: Hydrated, Igneous, and Amorphous) - representative of the local mineralogy at Oxia Planum has been developed for biosignature and mineralogy experiments, which will assist in interpreting data returned by the rover. The simulant is derived from orbital observations of Oxia Planum and its catchment area. As no in situ data is available for Oxia Planum, mineralogy from other comparable sites on Mars was used to design the simulant including orbital data from Arabia Terra and Mawrth Vallis and in situ data collected from Gale crater. The mineralogy, chemistry and physical properties of the simulant were characterised using standard laboratory techniques (SEM-EDS, XRF, XRD).Techniques analogous to rover instruments (Raman spectroscopy, Near-IR spectroscopy analogous to the Raman laser spectrometer and ISEM and MicrOmega instruments) were also used. The simulant is rich in Fe/Mg phyllosilicates with additional primary igneous and other alteration minerals and is an appropriate spectral and mineralogical analogue for Oxia Planum.