<p> Mid-infrared emissivity spectra are an extremely useful tool for determining bulk surface composition of planetary bodies. Our current interpretation of these spectra relies primarily on studies of spectra acquired in a terrestrial environment, which do not exhibit the same behavior as spectra measured on the surface of airless bodies like the Moon. From previous studies, we know that the environmental conditions in which mid-infrared spectra are measured affect the position and spectral contrast of spectral features used in compositional identification and analysis. The unique thermal environment within the upper 100s of microns of lunar regolith results in an anisothermal emissivity spectrum that cannot be directly compared to typical isothermal spectral libraries. It is also known that physical attributes of the material, such as particle size, will affect spectral features; however, this has not been studied in an airless environment. The second chapter of this dissertation is therefore dedicated to understanding the changes to mid-infrared spectra acquired under a simulated lunar environment due to particle size variation. </p><p> An additional aspect of the lunar environment not seen on Earth is the process of space weathering. Space weathering is the amalgamation of exposure to solar and cosmic radiation as well as micrometeoroid bombardment resulting in physical, chemical, and optical alteration of lunar regolith. For this work, I focus on the resulting albedo decrease in mature regolith, i.e., regolith that has been exposed to space weathering for a substantial period of time. In Chapter 3, I focus on the mid-infrared spectral changes due to albedo on pure minerals measured under a simulated lunar environment, and Chapter 4 describes the effect of albedo on emissivity data from the Diviner Lunar Radiometer Experiment, the only current mid-infrared instrument in orbit around the Moon. </p><p> From this work, I determine that both particle size and albedo affect mid-infrared emissivity spectral features in ways that complicate mineral identification and show how our laboratory work can enable better interpretation of spectra from the Moon, as well as other airless bodies within our Solar System.</p><p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10823197 |
| Date | 08 September 2018 |
| Creators | Shirley, Katherine Anne |
| Publisher | State University of New York at Stony Brook |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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