资源环境科技发展态势分析平台

Magma oceans were once ubiquitous in the early solar system, setting up the initial conditions for different evolutionary paths of planetary bodies. In particular, the redox conditions of magma oceans may have profound influence on the redox state of subsequently formed mantles and the overlying atmospheres. The relevant redox buffering reactions, however, remain poorly constrained. Using first-principles simulations combined with thermodynamic modeling, we show that magma oceans of Earth, Mars, and the Moon are likely characterized with a vertical gradient in oxygen fugacity with deeper magma oceans invoking more oxidizing surface conditions. This redox zonation may be the major cause for the Earth鈥檚 upper mantle being more oxidized than Mars鈥?and the Moon鈥檚. These contrasting redox profiles also suggest that Earth鈥檚 early atmosphere was dominated by CO₂ and H₂O, in contrast to those enriched in H₂O and H₂ for Mars, and H₂ and CO for the Moon.