Dimensions, density, and relief height of the Earth, Moon, and Mars are compared. It is concluded that there are two types of regions on Mars; highlands and depressions, differing in level of relief, in the thickness of the crust, and in chemical and mineralogical composition. Photographs from Mariner 9 and Mars 5 are discussed as revealing extensive Martian vulcanism, a wide ditch which may be of tectonic origin, and tributary-like networks or valleys. It is suggested that more perceptible manifestations of geological activity are to be expected on Mars than those discovered on the surface of the Moon.
NASA STI/Recon Technical Report N
- Pub Date:
- Earth Surface;
- Lunar Geology;
- Mars Surface;
- Mariner 9 Space Probe;
- Lunar and Planetary Exploration