SERTIS - Mapping the Moon in the thermal infrared

Kurzfassung

SERTIS (SElenological Radiometer and Thermal infrared Imaging Spectrometer) is an imaging spectrometer for the thermal infrared wavelength range with an integrated μ-radiometer. It is proposed as part of the payload for the planned German lunar orbiter. SERTIS is based on the technology of the MERTIS instrument currently under development for the ESA mission BepiColombo to Mercury. SERTIS will be the first instrument on a lunar orbiter studying the Moon in this wavelength range with a high spectral resolution. We will present here the science case for SERTIS and the importance of mapping the Moon in this so far largely unexplored spectral range. The data obtained by SERTIS will be highly complementary to existing and planned observations in the near-infrared, visual and UV wavelength range. The scientific goal of SERTIS is to provide detailed information about the mineralogical composition of the lunar surface layer by mapping the spectral emittance in the spectral range from 7-14μm. Based on this SERTIS has four main scientific objectives: Study of the lunar surface composition, identification of rock-forming minerals, global mapping of the surface mineralogy, and study of surface temperature and thermal inertia. SERTIS combines a mapping spectrometer covering the range from 7-14μm at a high spectral resolution of up to 90nm with an integrated μ-radiometer integrating over the wavelength range from 7-40μm. The spectral resolution of the spectrometer can be adapted depending on the actual surface properties to optimize the S/N ratio. SERTIS will globally map the surface with a spatial resolution of better than 100m and a S/N ratio of at least 100. SERTIS will map a significant part of the surface with a spatial resolution up to 35m.