Production of sodium vapor from exposed regolith in the inner solar systemThe likely supply of sodium to the lunar exosphere by impact vaporization, by charged particle sputtering, and by photon stimulated desorption has been calculated. These were each compared to the supply of sodium needed to maintain the observed sodium exosphere about the Moon. The two processes already known to act on the lunar regolith, impact vaporization and charged particle sputtering, appear to be sufficient to explain the observed column density of sodium in the lunar atmosphere. Photon-stimulated desorption, given the estimates for the yield of sodium due to this process available in the literature, would produce 100 to 1000 times more sodium than is observed. If impact vaporization is the main source of sodium to the atmosphere of Mercury, then sodium photo-ions in the exosphere of Mercury are efficiently recycled to the planet.
Document ID
19890049138
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Morgan, T. H. (NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Zook, H. A. (NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Potter, A. E. (NASA Johnson Space Center Houston, TX, United States)