SOME GEOLOGIC PROBLEMS OF MARS

Geological and geophysical knowledge and uncertainties concerning the surface and body of Mars are briefly discussed and evaluated. The large number of uncertainties in present data precludes an adequate model of Mars; reliable data are needed. Accurate values for the figure of the planet and the radii, seismic evidence of internal structure, and measurements of the outward heat flux across the surface are important and necessary for a satisfactory description of the body of Mars. Two types of television coverage from an orbiter are required to describe surface features. One type is needed to delineate gross topographic features, such as extensive highlands or basins, with resolution of about one kilometer. The second type is needed to search for evidence of orogenic and volcanic activity, areas of groundwater accumulation, sand dune patterns, etc., with resolution of about 10 meters. Some geological inferences which can be drawn from available photographic and photometric data concerning topography, areas of water accumulation, and biological activity are discussed. The priority of scientific geologic experiments is presented and some present instrumentation capabilities and deficiencies are listed.