The spectral characterization of the Ribbeck aubrite as mercury analog: the effect of heating in preparation for MERTIS flyby 5.

Kurzfassung

The MErcury Radiometer and Thermal Infrared Spectrometer (MERTIS) of the BepiColombo mission has as main goal to characterize the Hermean surface mineralogy by measuring the spectral emissivity of Mercury’s surface with a spatial resolution of at least 500 mpp [1]. During the 5th Mercury FlyBy of BepiColombo on the 2nd of December 2024, MERTIS will operate and perform surface measurements on a large area of Mercury. To prepare for the upcoming remote sensing measurements of MERTIS, analogue materials to simulate the expected mineralogy within our observed region need to be selected and studied in laboratory. The recently fallen Aubrite meteorite “Ribbeck” was chosen as analogue material, as this enstatite-rich material is highly reduced such as expected for the planet [2]. Microscopical XRF measurements and reflectance bulk spectra were acquired before and after heating Ribbeck at Mercury temperatures (up to 450 °C) to see the effect of heating on this material. These results will be used as a baseline for understanding the lab and remote sensing emissivity spectra once the BepiColombo spacecraft reaches Mercury and MERTIS can operate.