Simulations Show Moon Could Form Intact in Hours, Challenging Fluid Collision Models

New computer simulations indicate that the Moon‑forming impact may have depended heavily on the temperature and material strength of early Earth and its impactor, Theia. While some collision scenarios produce the familiar debris disk that later coalesces into the Moon, others can generate an intact lunar body in roughly five hours. The study shows that the outcome varies with how hot and rigid the colliding bodies were, contradicting the long‑held assumption that the giant impact could be treated as a fluid‑dynamic event. These results suggest that future models of lunar and planetary formation must incorporate solid‑state physics and thermal conditions to accurately reproduce the Moon’s origin.