Fig. 6: 3-µm band shape comparison for sulfate-bearing mixture, pure ferrihydrite and Martian dust.
From: Detection of ferrihydrite in Martian red dust records ancient cold and wet conditions on Mars
The spectral comparison reveals that the 3-µm band’s long-wavelength wing and particularly its inflection point near 3.8 µm in our ferrihydrite-basalt-sulfate mixture matches the Martian dust spectrum, suggesting the possible presence of sulfates in the Martian dust. Reflectance spectra of both the ferrihydrite-basalt-sulfate mixture and pure ferrihydrite were measured under ambient conditions with dry air purging immediately before each acquisition. Normalized at 2.5 µm. Source data are provided as a Source Data file.
