Atmospheric Characterization of Magmatic Exoplanets

Objective

Active volcanoes and magma oceans were once widespread in our solar system. By influencing atmospheric composition, climate and habitability, they played a fundamental role in the evolution of many moons and planets. Yet, observational evidence of how these magmatic processes influence the state of a planet is so far limited to our solar system. However, recent observations of the 55 Cancri and L 98-59 systems demonstrate that we now have the sensitivity to detect and characterize the effects of magmatic processes on the atmospheres of planets around other stars. The MAGMA project will open this frontier by combining exoplanet and planetary sciences to explore how magmatic processes governs rocky exoplanets. Unlike most similar efforts that focus primarily on JWST data, MAGMA will make ground-based high-resolution spectroscopy its central tool, exploiting KPF and CARMENES data to search for volcanic gases, probe atmospheric escape, and link observable signals to planetary interiors. These datasets will be complemented by select JWST, CHEOPS and Hubble observations. MAGMA has three goals: (i) understanding the conditions for lava worlds to retain their atmospheres, (ii) testing whether volcanism can replenish atmospheres, and (iii) providing the first observational constraints on the interior properties of rocky exoplanets. The project carries low risk, as much of the data has already been collected, and even non-detections will yield stringent upper limits of lasting scientific value. By pushing the capabilities of KPF and CARMENES to their limits, MAGMA will also act as a critical pathfinder for the Extremely Large Telescope (ELT), preparing the tools needed to characterize rocky planets in the decades ahead. In doing so, it will establish a multidisciplinary framework for understanding how magmatic processes shape the evolution and habitability of planets across the galaxy.