Properties of Lunar Surface Material From Direct Observation by Spacecraft—Summary*


  • Leonard D. Jaffe


The seven unmanned spacecraft that have landed on the moon, together with the lunar orbiting spacecraft, provided considerable information on the chemical composition, mechanical properties, and small-scale structure of the lunar surface. This abstract, prepared prior to manned landing on the moon, summarizes some of the results; a more complete account is available elsewhere [Jaffe, 1969a, c]. Space-craft results pertaining to the lunar interior and to the surroundings of the moon are omitted from this paper, as are results based on data from electromagnetic detectors alone, which other papers at this symposium discuss and interpret.


The disturbances of the lunar surface produced by Surveyor landing gear, surface sampler devices, and rocket engines showed that both maria and high-lands are covered with a layer of fine particles.