Collaborative Research: GLOW: Iron Redox Reactions in Magma Oceans and Differentiation of Rocky Planets

Earth’s mantle is far more oxidized than its building blocks. The oxidation of the mantle has a large effect on our planet’s habitability. Because of the oxidation, our atmosphere contains enough oxygen to support life. One theory suggests that mantle oxidation occurred during the “magma ocean” stage of Earth’s history. When early Earth was still molten and forming, it was covered by a hot and deep ocean of magma. Studying the oxidation process is important for understanding the role of the magma ocean in making Earth habitable. Scientists also want to know how this process applies to other planets and exoplanets. This research project will bring together geoscientists and astronomers to study how planets become habitable through mantle oxidation. The project will also create educational materials and answer questions about the relationship between geology and life. This Geoscience Lessons for and from Other Worlds (GLOW) award will enable researchers to conduct experiments at pressures, temperatures, and compositions directly relevant to silicate-metal reactions in magma oceans of Earth and Earth-like planets. The experiments will use peridotite glass starting materials synthesized in a levitation furnace. The samples will be subjected to pressures and temperatures up to 140 GPa and 6000 K in laser-heated diamond anvil cells. The products will be analyzed for their ferric and ferrous iron ratio using synchrotron Mössbauer spectroscopy. The experimental results will be incorporated into a thermodynamic model that will allow prediction of the oxidation of a planetary mantle and its habitability, depending on the size of the planet and the conditions of formation of its core. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.