Flying automated laboratories to the planets.

Review of results obtained by instrumented spacecraft in investigation of the planets, mainly Mars. It appears that Mars is a world of varying topographical structure, some of which must have been created by the same processes that sculptured the moon and by others thus far unique in the solar system. The atmosphere is too thin to shield the surface, and there are no traces of liquid water. The very large recent dust storm is discussed. Mariner 9 has revealed definite indication of probable volcanic activity on Mars in recent geologic times.-