M³ global and targeted image spectra from five study sites with different thermal corrections applied, along with M³ comparison spectra for reference. (a) Spectra from PDS-corrected M³ targeted image m3t20090421t183929. (b) Spectra from PDS-corrected M³ global images M3G20090212T103632 (morning) and M3G20090712T175144 (midday) showing a time-of-day comparison. The dashed line is at ∼2.8 μm. (c) M³ spectra from the Bullialdus crater central peak exhibiting pyroxene mineral signatures with interpreted OH⁻ absorptions by R. Klima et al. (2013). (d) M³ spectra acquired from M3G20090212T103632 (morning) and M3G20090712T175144 (midday) global images at five study sites showing time-of-day comparison among RF, RRF1.5, and RRF2.0 thermally corrected images. The dashed line is at ∼2.8 μm. The following spectra are scaled for image correction grouping purposes: RRF1.5 Bunsen A (morning), RRF 1.5 Galvani D (midday), RRF2.0 Bunsen A (morning). M³ Aristarchus region spectra from R. E. Milliken & S. Li (2017). The following applies to (a), (b), and (d). All spectra are ROI averages; spectra colors correspond to study site colors in Figure 2. (a)–(c) spectra were acquired from M³ images with the thermal correction of R. N. Clark et al. (2011) applied. (d) spectra were acquired from M³ images with the K. Wohlfarth et al. (2023) thermal correction applied. (e) spectra were acquired from M³ images with the S. Li & R. E. Milliken (2016) thermal correction applied.