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Measurements of Photoelectric Yield and Physical Properties of Individual Lunar Dust GrainsMicron size dust grains levitated and transported on the lunar surface constitute a major problem for the robotic and human habitat missions for the Moon. It is well known since the Apollo missions that the lunar surface is covered with a thick layer of micron/sub-micron size dust grains. Transient dust clouds over the lunar horizon were observed by experiments during the Apollo 17 mission. Theoretical models suggest that the dust grains on the lunar surface are charged by the solar UV radiation as well as the solar wind. Even without any physical activity, the dust grains are levitated by electrostatic fields and transported away from the surface in the near vacuum environment of the Moon. The current dust charging and the levitation models, however, do not fully explain the observed phenomena. Since the abundance of dust on the Moon's surface with its observed adhesive characteristics is believed to have a severe impact on the human habitat and the lifetime and operations of a variety of equipment, it is necessary to investigate the phenomena and the charging properties of the lunar dust in order to develop appropriate mitigating strategies. We will present results of some recent laboratory experiments on individual micro/sub-micron size dust grains levitated in electrodynamic balance in simulated space environments. The experiments involve photoelectric emission measurements of individual micron size lunar dust grains illuminated with UV radiation in the 120-160 nm wavelength range. The photoelectric yields are required to determine the charging properties of lunar dust illuminated by solar UV radiation. We will present some recent results of laboratory measurement of the photoelectric yields and the physical properties of individual micron size dust grains from the Apollo and Luna-24 sample returns as well as the JSC-1 lunar simulants.
Document ID
20050237054
Document Type
Preprint (Draft being sent to journal)
Authors
Abbas, M. M. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Tankosic, D. (Alabama Univ. Huntsville, AL, United States)
Craven, P. D. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Spann, J. F. (NASA Marshall Space Flight Center Huntsville, AL, United States)
LeClair, A. (Alabama Univ. Huntsville, AL, United States)
West, F. A. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Taylor, L. (Tennessee Univ. Knoxville, TN, United States)
Hoover, R. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2005
Subject Category
Lunar and Planetary Science and Exploration
Meeting Information
Dust in Planetary Systems(Kauai, HI)
Distribution Limits
Public
Copyright
Other