Evidence about hydrate and solid water in the Martian surface from the 1969 Mariner infrared spectrometer

Results of laboratory simulation studies and comparative computer analyses of infrared spectral data regarding the presence, distribution, and form of condensed-phase water in the Martian surface. The data were obtained with the aid of the Mariner 6 and 7 spacecraft which were equipped with infrared spectrometers recording the infrared spectrum from 1.9 to 14.4 microns. From the analysis of these data evidence is obtained which signifies some sort of compositional and/or particle size variability of the extent and nature of hydration. Changes are noted which could be due to ice thinly covering a small fraction of the planetary surface in particularly cold spots, possibly on partially shaded slopes. At southerly latitudes, the fraction so covered seems to increase as the polar cap edge is approached. It is therefore concluded that there is strong evidence of ice formation on the planetary surface at the edge of the polar cap.