Rapid accretion of enstatite chondrite (EH)-like embryos as impactors for the proto-Earth

Enstatite chondrites-like impactors are proposed as key contributors to the proto-Earth and are believed to have undergone differentiation. However, this differentiation remains enigmatic: their small size precludes gravity-driven permeable flow, and enstatite exhibits a high melting temperature. Here, we report high-pressure melting experiments on EH3 chondrite, coupled with three-dimensional X-ray computed tomography, showing that more than 20% of silicate partial melting can enable efficient metal segregation. Thermodynamic simulations of EH chondrite-like embryos thermal evolution further demonstrate that heat from radioactive decay allows core formation only if embryos accreted within 1.4 Myr post-CAIs. In contrast, EH chondrite parent bodies formed later (1.92–2.0 Myr post-CAIs) with radii of 110–190 km. Our findings suggest two distinct evolutionary trajectories of EH chondrite-like embryos, providing constraints on core formation in small planetary embryos and fundamental references for the formation of planets in the early solar system. Enstatite chondrite-like embryos and enstatite chondrite parent bodies accreted very early and followed two distinct evolutionary trajectories, according to high-pressure melting experiments and thermodynamic simulations