ABSTRACT

This chapter discusses planetary remote sensing. The emphasis will be on the terrestrial planet Mars. The information to be presented is admittedly dated, but the principles of analysis are fundamental and applicable to other planetary surfaces yet to be analyzed that have no vegetation. The Martian landers carried several experiments for determining the chemical composition of the Martian surface but not its mineralogical composition; this remains to be done with a sample return. The fine debris that was found at both landing sites had nearly the same chemical composition as a result of global dust storms that carried loose surface particles to all parts of the planet. The soil is rich in silicon and iron. It appears that highly oxidized iron compounds are responsible for the reddish color. Trenches 15 cm deep were dug by a scoop on a lander and it appears that bonding of the surface particles occurred. On the lunar surface, vacuum bonding is the result of van der Waals forces between the molecules. On the Martian surface, there is about 10 mbar surface pressure, and the bonding could be due to frost, shown to exist in the atmosphere. The evidence is inferred from the requirement of increasing the Martian air mass to 3.8, to satisfy the atmospheric modeling requirement. The additional carbon dioxide in the atmosphere could exist as frost or in association with the dust particles. On the earth trenches could not be dug easily in the dry soil as in wet beach sand. Because carbon dioxide exists as ice on the planet Mars and possibly on other planetary, asteroidal, and cosmic bodies it is appropriate to indicate a technique and the results of such a measurement. This is described following Egan and Spagnolo [1].