Overview
- A new peer-reviewed paper in Science Advances uses high-resolution 3D models to reproduce the South Pole–Aitken basin’s unusual, tapered shape.
- The best match involves a differentiated impactor about 260 kilometers wide striking from north to south at a shallow angle near 30 degrees.
- The modeled impact speed of roughly 13 km/s fits the basin’s form and helps explain its asymmetric interior uplift.
- The simulations predict a butterfly-like ejecta pattern with mantle material about 550 km beyond the rim downrange and about 650 km cross-range, with little uprange.
- Because NASA plans to land Artemis III near the lunar south pole, the team says astronauts could encounter mantle-bearing ejecta there, though only returned samples can confirm the model and its hint that the impactor came from the early Mars zone.