Left: visible to near-infrared bidirectional (i ≈ 30° (dashed line) and 45° (solid lines), e = 0°) diffuse reflectance spectra of one Murchison pellet before (black) and after (colored lines, only measured at 45°) irradiation with 3 × 10¹⁶ He⁺/cm² (orange) and 6 × 10¹⁵ Ar⁺/cm² (purple), compared with RELAB powder spectra (gray) as presented in Cloutis et al. (2011; i = 30°, e = 0°). Right: visible to near-infrared bidirectional diffuse reflectance spectra (viewing geometry at ≈30°) on both pellets before irradiation to show surface heterogeneity of each sample.