Overview
- Researchers published new modelling on Monday, June 29, 2026, arguing that repeated large asteroid impacts during the Hadean pumped enough energy into Earth to dominate its thermal budget for much of the first 500 million years.
- The models show impact heating penetrated below the surface, thinning or destroying early crust and driving mantle melting that produced vast volumes of basaltic magma.
- Those long-lived effects likely kept the protocrust thin, weak, and partly molten and changed volcanic and tectonic behavior for tens to hundreds of millions of years.
- The team says repeated impacts could have promoted processes that built silica-rich, continental-like rocks by fracturing crust, enabling water circulation, and forcing repeated magmatism, while also explaining the near absence of intact Hadean rocks.
- Planetary evidence from the Moon and recent lunar‑meteorite work supports extended bombardment but also shows some high‑temperature impacts persisted after the classical heavy‑bombardment window, so researchers call for models and observations to be linked more closely to refine timing and scale.