Mercury: Assessment of the Geology of Late Eruptions and Volatiles

The MESSENGER mission imaged explosive volcanic deposits on Mercury: a surprising result because Mercury’s proximity to the Sun should have depleted its constituents in volatiles. Mercury’s large core suggests its rocky shell was stripped by some process, which most likely would have removed its volatiles too. The volatiles’ species, how Mercury retained them, and how they were concentrated in Mercury’s magmas are unknown. Mercury’s volcanic plains formed ≥3.5 billion years ago, before magma ascent routes were closed by global contraction, but some impact craters liberated magmas for an unknown time afterward. The University of Leicester-built Mercury Imaging X-ray Spectrometer on the ESA-JAXA BepiColombo mission will measure Mercury’s composition. Mercury’s explosive volcanic deposits are important targets, but it is unknown how MIXS will respond to their exotic physical and chemical properties under different observation conditions. Vital groundwork remains to be done before BepiColombo arrives in 2026. Through the Mercury: Assessment of the Geology of Late Eruptions and Volatiles (MAGLEV) action, I will: (1) conduct an interdisciplinary study of materials excavated by Mercury’s Caloris basin to provide the deepest constraint on Mercury’s volatile subsurface distribution to assess how they were concentrated in Mercury’s magmas, with implications for the planet’s formation; (2) measure the volumes and ages of late-stage lavas found within impact craters, to inform us about the thermal evolution of Mercury and Mercury-like exoplanets, and; (3) quantify the response of the University of Leicester’s MIXS emulator to synthetic analogues of key Mercury terrains, to optimise MIXS operating parameters. By conducting MAGLEV at the Institute for Space based at Space Park Leicester, I will gain new research skills, planetary perspectives, teaching opportunities, and space mission experience, all of which will enhance my short-to-long term career development.