Mid‐Infrared Spectroscopy of Feldspars From the Bühl Basalt (Northern Hesse, Germany) Formed Under Reducing Conditions as Terrestrial Analogue of Mercury for MERTIS

Abstract

Mercury is the innermost planet in our Solar System and the target of the BepiColombo spacecraft, which is equipped with the thermal infrared (IR) spectrometer and radiometer MErcury Radiometer and Thermal Infrared Spectrometer (MERTIS), besides other instruments (Benkhoff et al., 2010;Hiesinger et al., 2010Hiesinger et al., , 2020. The spectrometer of MERTIS has 78 spectral channels in the wavelength range between 7 and 14 μm (Hiesinger et al., 2010(Hiesinger et al., , 2020. The footprint of the measurements on Mercury will globally reached 500 m × 500 m and better than this at up to 10% of the surface (Hiesinger et al., 2020). The goals of MERTIS are (a) studying Mercury's surface composition, (b) identifying of rock-forming minerals, (c) mapping the surface mineralogy, and (d) studying the thermal inertia (Hiesinger et al., 2010(Hiesinger et al., , 2020. To achieve the goals of MERTIS, it is necessary to build a spectral library of fully characterized samples of potential constitute minerals of Mercurys' surface and to study the behavior of mixtures of these minerals (Weber et al., 2018). Analog experiments and modal calculations with chemical compositions derived from MESSENGER data were performed (e.g., Morlok et al., 2021;Namur & Charlier, 2017) to identify potential mineral candidates.