Moon formation may have occurred in five hours after Earth impact

New computational simulations published in The Astrophysical Journal Letters suggest that the Moon may have formed within just five hours following a catastrophic collision between the early Earth and a Mars-sized protoplanet named Theia.

While the giant impact hypothesis has long posited that debris from this collision coalesced to form the Moon, previous models suggested this process took much longer. The new research, led by geologist Adin Denton of the Southwest Research Institute, incorporates the material strength and thermal properties of the colliding bodies—factors previously understudied.

The simulations indicate that if the Earth and Theia were sufficiently hot, the resulting debris field could have rapidly consolidated into a single satellite. This accelerated timeline challenges existing geological epochs previously assigned to lunar formation and provides new insights into the stability and evolution of the early solar system.