Scientists have recently made exciting discoveries about the South Pole–Aitken (SPA) basin, the moon’s largest and oldest impact crater. These insights could greatly influence NASA’s Artemis mission, set to launch in 2028, which aims to land close to this location. The findings highlight the chance to collect unique samples from the moon’s mantle, a breakthrough in lunar exploration.
The SPA basin stretches over 1,200 miles across the moon’s far side. For years, experts debated how it formed, with two main theories about the direction of the impactor that created it. A new study in Science Advances provides clarity through advanced 3D simulations. Researchers found that the impactor likely came from north to south, which helps explain the basin’s unique shape.
“Large basins on the moon and other solid bodies are ellipses that taper downrange. SPA’s tapering toward the south supports a southward impact trajectory.”
This understanding will guide future lunar missions, especially Artemis, which hopes to land near the SPA basin’s rim.
In their research, scientists simulated various impact scenarios, considering the size and speed of the impactor. They believe it was about 260 kilometers wide and struck the moon at a shallow angle. The study’s lead authors highlight that the impactor likely originated from the Mars zone, not Venus or Earth.
“Our best-fit impact velocity of 13 km/s suggests that the SPA impactor was on a low inclination Earth-like orbit before it struck the moon.”
The simulation also revealed that the SPA impactor ejected mantle material in a distinct pattern. This ejected material spread out like a butterfly, reaching 550 kilometers beyond the basin’s rim in one direction and 650 kilometers in a cross-range direction. This unique ejecta pattern offers Artemis a rare chance to sample lunar mantle material, which past missions couldn’t achieve.
“For the previously assumed south-to-north impact, the Artemis landing region would have been devoid of ejecta from the lunar mantle. Instead, our models suggest that Artemis III can collect these crucial samples if our interpretation is right.”
Studying these mantle samples could provide big insights into the moon’s history and the early solar system. In a world where lunar exploration can change our understanding of planetary evolution, the Artemis mission stands out as a game-changer.
