Astronomers have made significant progress in deciphering the origins of the South Pole–Aitken (SPA) basin, which is the largest and one of the most enigmatic impact craters on the Moon. This colossal area, spanning over 2,500 kilometers in diameter, is regarded as one of the most ancient marks of cosmic collisions within the Solar System and has long attracted intense scientific scrutiny.
The primary reason for the focus on the SPA basin stems from the fact that such a massive impact event would have likely excavated material from deep within the lunar mantle—layers typically concealed beneath the satellite’s crust and largely inaccessible for direct study.
A research team led by Shigeru Wakita from Purdue University conducted intricate three-dimensional impact simulations, concluding that the region most likely formed following the impact of a substantial asteroid, roughly 260 kilometers across.
According to the scientists’ calculations, the impacting object was composed of a composite mix of rocky materials and iron. The collision occurred at a relatively shallow angle—approximately 30 degrees—at a velocity around 13 kilometers per second.
The study’s authors posit that this specific scenario offers the best explanation for the distribution of materials observed in the lunar south pole region. The impact would have ejected vast quantities of subsurface matter, including mantle fragments, which hold considerable scientific value today.
These excavated rocks have the potential to offer researchers deeper insights into the Moon’s internal structure and help pin down the precise timing of the ancient impact that created the South Pole–Aitken basin.
Scientists highlight that the Artemis program could play a crucial role in the continued study of this region. Should NASA’s schedule remain on track, astronauts might be able to collect rock samples near the lunar south pole as early as 2028.
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