A decapitated, differentiated asteroid likely created the South Pole–Aitken basin, the largest impact crater on the Moon [1].
This discovery provides a map for NASA's Artemis missions, as the impact scattered material from deep within the lunar interior toward the south pole. By sampling these deposits, astronauts may access lunar mantle material without drilling deep into the surface.
Planetary scientists said that the asteroid, which measured 160 miles in width [2], struck the lunar surface at a shallow angle billions of years ago [1, 2]. This specific trajectory caused a massive, basin-forming event that excavated materials from the Moon's deep interior and flung them across the landscape [1, 2].
The South Pole–Aitken basin is located on the far side of the Moon, extending near the lunar south pole [1, 3]. Because the asteroid was differentiated, meaning it had a distinct core and mantle, the collision dynamics were unique. The "decapitated" nature of the asteroid refers to its fragmented state prior to or during the impact, which influenced how the basin formed [1, 2].
NASA is currently targeting the lunar south pole for upcoming Artemis landings [1]. The research suggests that the proof of this ancient collision, including the excavated deep-crust material, is located near the regions where astronauts are expected to land [1, 3].
These findings help researchers understand the early history of the solar system and the composition of the Moon's interior. The ability to collect deep-seated lunar material from the surface could significantly accelerate the study of planetary evolution [1].
“The South Pole–Aitken basin is the Moon's largest impact crater.”
The identification of the South Pole–Aitken basin's origin transforms the lunar south pole into a high-priority geological archive. Because a massive impact effectively 'mined' the Moon's interior billions of years ago and deposited that material on the surface, NASA can potentially study the Moon's deep composition through surface sampling, reducing the technical burden of deep-core drilling during Artemis missions.
