Rationale for BepiColombo Studies of Mercury’s Surface and Composition
Authors: Rothery David A. , Massironi Matteo , Alemanno Giulia , Barraud Océane , Besse Sebastien , Bott Nicolas , Brunetto Rosario , Bunce Emma , Byrne Paul , Capaccioni Fabrizio , Capria Maria Teresa , Carli Cristian , Charlier Bernard , Cornet Thomas , Cremonese Gabriele , D’Amore Mario , De Sanctis M. Cristina , Doressoundiram Alain , Ferranti Luigi , Filacchione Gianrico , Galluzzi Valentina , Giacomini Lorenza , Grande Manuel , Guzzetta Laura G. , Helbert Jörn , Heyner Daniel , Hiesinger Harald , Hussmann Hauke , Hyodo Ryuku , Kohout Tomas , Kozyrev Alexander , Litvak Maxim , Lucchetti Alice , Malakhov Alexey , Malliband Christopher , Mancinelli Paolo , Martikainen Julia , Martindale Adrian , Maturilli Alessandro , Milillo Anna , Mitrofanov Igor , Mokrousov Maxim , Morlok Andreas , Muinonen Karri , Namur Olivier , Owens Alan , Nittler Larry R. , Oliveira Joana S. , Palumbo Pasquale , Pajola Maurizio , Pegg David L. , Penttilä Antti , Politi Romolo , Quarati Francesco , Re Cristina , Sanin Anton , Schulz Rita , Stangarone Claudia , Stojic Aleksandra , Tretiyakov Vladislav , Väisänen Timo , Varatharajan Indhu , Weber Iris , Wright Jack , Wurz Peter , Zambon Francesca 
Published: June 2020

BepiColombo has a larger and in many ways more capable suite of instruments relevant for determination of the topographic, physical, chemical and mineralogical properties of Mercury’s surface than the suite carried by NASA’s MESSENGER spacecraft. Moreover, BepiColombo’s data rate is substantially higher. This equips it to confirm, elaborate upon, and go beyond many of MESSENGER’s remarkable achievements. Furthermore, the geometry of BepiColombo’s orbital science campaign, beginning in 2026, will enable it to make uniformly resolved observations of both northern and southern hemispheres. This will offer more detailed and complete imaging and topographic mapping, element mapping with better sensitivity and improved spatial resolution, and totally new mineralogical mapping.

We discuss MESSENGER data in the context of preparing for BepiColombo, and describe the contributions that we expect BepiColombo to make towards increased knowledge and understanding of Mercury’s surface and its composition. Much current work, including analysis of analogue materials, is directed towards better preparing ourselves to understand what BepiColombo might reveal. Some of MESSENGER’s more remarkable observations were obtained under unique or extreme conditions. BepiColombo should be able to confirm the validity of these observations and reveal the extent to which they are representative of the planet as a whole. It will also make new observations to clarify geological processes governing and reflecting crustal origin and evolution.

We anticipate that the insights gained into Mercury’s geological history and its current space weathering environment will enable us to better understand the relationships of surface chemistry, morphologies and structures with the composition of crustal types, including the nature and mobility of volatile species. This will enable estimation of the composition of the mantle from which the crust was derived, and lead to tighter constraints on models for Mercury’s origin including the nature and original heliocentric distance of the material from which it formed.