2009 Annual Science Report
University of Hawaii, Manoa Reporting | JUL 2008 – AUG 2009
Irradiation of Lunar Samples
We are irradiating silicate samples with 1 keV energetic protons (H+) to simulate weathering of silicate rocks on the moon from the solar wind. Here, the goal is to demonstrate the production of water through interaction of the impinging particles with oxygen atoms within the silicate material. This should help explain the recent discoveries from the Indian Chaandrayan-1 spacecraft mission which recently discovered water within the upper layers of the surface.
Recently, the presence of water (H2O) and/or hydroxyl (-OH) on the lunar surface has been detected by the Moon Mineralogy Mapper (M3), NASA’s guest instrument onboard the Indian Chandrayaan-1 spacecraft. Data from Cassini taken in 1999 as well as from the Deep Impact spacecraft have confirmed these results. The hypothesis is that this water is formed due to the interaction of energetic protons (H+ ions) from the solar wind interacting with silicate minerals on the moons surface. Our aim is to modify our laboratory set-up in order to study the validity of this hypothesis. This project is still in the preliminary stages. The ion source has been installed into our UHV vacuum system and is currently being tested. In addition, the required chemicals and rock samples have been received, minus pyroxene which will be ordered later. We are also in the process of refining the method to which our samples will be prepared. The three proposed methods are as follows: i) Cutting thin slabs of each mineral approximately 2mm thick which will be held over our target, ii) pressing nanoparticles directly onto our silver mirror targets, and iii) direct laser ablation of minerals onto the target which is being done by one of our collaborators. We expect to be getting some preliminary results in the next couple of weeks.