In the spring newsletter, we reported Michelle Thompson as the recipient of the 2014 Shandel (now Curson) Travel Scholarship. Michelle is beginning her fourth year as a graduate student working with Assistant Professor Tom Zega. She used the travel support to attend the annual Microscopy and Microanalysis Conference in Hartford, Connecticut, August 2014, and to present her work as a talk titled, “Electron Energy‐Loss Spectroscopy of Iron Nanoparticles in Lunar Soil using an Aberration-­Corrected Scanning Transmission Electron Microscope.” Michelle describes the experience as a "unique opportunity to present my work to both the planetary science community and the community of microscopy experts."  Michelle's paper was selected for a Presidential Scholar award. 

Michelle's dissertation focuses on the effects of space weathering processes and how they manifest themselves in soils on airless bodies. She studies the effects of space weathering in samples from the Moon and near-Earth asteroid Itokawa. The lunar samples used in her analysis were returned from the Moon by the Apollo missions and the samples from Itokawa were collected by the Japanese Aerospace Exploration Agency’s Hayabusa mission.

The effects of space weathering are concentrated in the outer one hundred nanometers of soil grain surfaces. In order to study these features at such a fine scale, Michelle uses an instrument called a transmission electron microscope (TEM), which allows her to get crystal structure and chemical information from samples at very small scales—the perfect tool for providing insight into space weathering processes. Among the space weathering features Michelle has been analyzing are iron nanoparticles in lunar soil, with each particle measuring only a few nanometers in size. These nanoparticles are produced through various space weathering processes and are responsible for changing the optical properties of the surface soils. Until recent advances in electron microscopy, scientists were unable to study the oxidation state Fe within individual particles. By using a state-of-the-art TEM, our study suggests these nanoparticles are not composed entirely of metallic iron, but a mixture of oxidation states. This has important implications for the nature of space-weathering processes on the surfaces of airless bodies.

The Shirley D. Curson Education Plus Fund in Planetary Sciences and LPL (formerly the Shandel Education Plus Fund) was established by Shirley Curson, a generous donor and friend of LPL, for the purpose of supporting travel expenses outside the state of Arizona during summer break. The award is open to students in the Department of Planetary Sciences and Lunar and Planetary Laboratory who propose to fund study, museum visits, special exhibits, seminars, instruction, competitions, research and other endeavors that are beyond those provided by the normal campus environment and are not part of the student’s regular curriculum during the recipient’s school year.