Comparison of Mid IR Spectra of Silicate and Glass Under High Vacuum

Abstract

On board the BebiColombo mission [1] is the MERTIS- (MErcury Radiometer and Thermal Infrared Spectrometer) instrument, which collects emission spectra in the range of 7 μm to 14 μm (spectrometer channels) and 7 μm to 40 μm (radiometer channels) of surface minerals [2,3]. For the investigation of the surface mineralogy of Mercury, understanding the spectral characteristics in the mid-IR range is crucial [2]. Two expected endmember-materials on the surface of Mercury are plagioclase and glass. Hence, our study focuses on the investigation of these two materials [4,5]. Knowing the surface composition of Mercury will lead to a deeper understanding of its evolution and history, and willfurther improve our understanding of the formation of the early Solar System [2]. In order to accurately interpret future spectra, we produced a series of mixtures of the above-mentioned materials with different mixing ratios. In an effort to reproduce the conditions on the Mercury surface for our measurements as realistically as possible, the samples were studied under a high vacuum and in the loose powder state to simulate regolith. In addition, pellets were investigated for comparison of presented results. Aim of our study is to investigate the changes in spectral properties of plagioclase, glass, and their mixtures in the mid-IR region for the MERTIS instrument.