MARS SURFACE-COMPOSITION FROM REFLECTANCE SPECTROSCOPY - SUMMARY

Visible and near-infrared (0.3-2.6micrometres) reflectance spectra of the martian surface have been obtained primarily from earth-based telescopic observations, and multispectral images have been obtained both from spacecraft and earth-based observations. Observations in this wavelength region have confirmed the bimodal albedo distribution of surface materials, first observed visually. All spectra of Mars are characterized by strong Fe3+ absorptions from the near-UV to about 0.75micrometer. Darker regions show this effect to a lesser degree, and are interpreted to be less oxidized materials. Other surface characteristics are discussed. -from Authors