Other
Scientific paper
Dec 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011agufm.p13d1729p&link_type=abstract
American Geophysical Union, Fall Meeting 2011, abstract #P13D-1729
Other
[5419] Planetary Sciences: Solid Surface Planets / Hydrology And Fluvial Processes, [5422] Planetary Sciences: Solid Surface Planets / Ices, [5462] Planetary Sciences: Solid Surface Planets / Polar Regions, [5470] Planetary Sciences: Solid Surface Planets / Surface Materials And Properties
Scientific paper
Temperature Program Desorption (TPD) experiments were performed to measure the thermal desorption activation energies of water on lunar regolith analogs. These data provide constraints for modeling water transport and possible formation on/in the lunar regolith, with likely application to other rocky airless solar system bodies as well. Mechanically micronized JSC-1A was chosen to simulate lunar mare regions, micronized albite was used to represent feldspars in the lunar highlands, and synthetic basaltic glass similar to Apollo glasses were examined to constrain the importance of amorphous vs. crystalline phase1 of the lunar surface materials. Water desorption was observed during the initial heating of both mineral samples to 750 K under ultra-high vacuum, with Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) spectra indicating probable recombinative desorption of hydroxyls above ~450 - 500 K. After then intentionally dosing extrinsic water, no dissociative chemisorption of water (i.e. formation of surface hydroxyl sites) was observed on these samples over laboratory timescales. However, JSC-1A and albite were found to have a distribution of molecular chemisorption sites for water with albite samples having at least twice as many as the JSC-1A by mass. The glass slab only exhibited physisorption of water as ice2. Assuming diffusion to be negligible on the experimental timescale, fitting the TPD profile required a distribution function with desorption activation energies ranging from ~0.45 eV (multilayer water ice) up to 1.3 eV3. This distribution function was then used to estimate the concentration of water that could survive the lunar diurnal heating cycle following a saturating pulse of water (such as from a wet impactor). The estimate showed water concentrations would decrease with decreasing latitude (i.e. with increasing maximum surface temperature). Making the assumption that the water exposure had sampled the entire powder film during our TPD experiments, less than 1 ppm of water would remain at 75 degrees latitude after one day and about 10 ppm would survive one summer day near the sunlit lunar pole. Extrapolation to 50 million years results in less than 1 ppm of water remaining at any lunar latitude.
Aleksandrov Aleksei
Darby Dyar M.
Grieves Gregory A.
Hibbitts C.
Johnson Alexis M.
No associations
LandOfFree
Water Interactions with Micronized Lunar Analogs and Application to the Behavior of Water on the Moon does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Water Interactions with Micronized Lunar Analogs and Application to the Behavior of Water on the Moon, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Water Interactions with Micronized Lunar Analogs and Application to the Behavior of Water on the Moon will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-868555