A consolidated Mössbauer spectrum for undisturbed soils from Gusev Crater, Mars

Abstract Mössbauer analyses from MIMOS II data collected on Mars provided breakthrough insights into iron mineralogy of the planet’s surface. Resulting from limited measurement time, science operations were divided among multiple instruments, restricting the detection of minor Fe-bearing mineral phases (below 5% WSA). MIMOS II records Mössbauer spectra at 10 K intervals, and to enhance signal to noise ratios, spectra from different intervals were combined, when applicable. For instance, temperature variations between 190 K and 270 K in basaltic samples do not significantly impact the spectra, allowing data from all intervals to be integrated. By combining MIMOS II data from various soil samples and over different temperature ranges, a consolidated Mössbauer spectrum for Martian soil at Gusev Crater is proposed, aiming to identify potential minor Fe-bearing mineral phases on the planet’s surface. This work combines Mössbauer experiments conducted on undisturbed soils within 10 K and all experiments conducted by Spirit until sol 2062.