Mercury is the smallest of the terrestrial planets, and therefore represents an end-member in the process of planetary formation. Mercury has been the object of very great attention by the European community since the launch of the ESA/JAXA BepiColombo mission for orbit insertion in 2025. The previous NASA/MESSENGER mission carried out a study of the planet (2011 - 2015). MESSENGER observations made it possible to highlight unexpected characteristics of its surface (e.g, high concentration of volatile, iron deficiency, volcanic flows, etc.) whose implications for the formation and evolution of the planets of the Solar system are crucial. MESSENGER's observations are available to better characterise the Hermean surface through the observations of spectrometer, camera and altimeter. We have created a database (MeSS: Mercury Surface Spectroscopy) containing the 4.7 million observations obtained by the MASCS instrument. Recently, we highlighted the specific characteristics of pyroclastic deposits (Besse et al., 2020), and the great potential of these data to constrain volcanic episodes (Rothery et al., 2020), as well as geological properties with very high spatial resolutions (Barraud et al., 2020). We wish to understand the composition and nature of the evolutionary processes of the surface of Mercury. The objective is to exploit this database of spectral parameters to better characterise the surface composition of Mercury using new and innovative approaches. To this end, state-of-the-art machine learning techniques will be used (K-means, clustering, etc.) to exploit the 4.7 millions spectra in a way never done so far for Mercury. A back and forth analysis will be done to exploit correlation found in the spectral domain with Mercury's surface properties. The results will be compared to laboratory measurements scheduled in 2021/2022, and dedicated new measurements. This work will help prepare and better target the scientific observations of the BepiColombo mission.
