What helped to change the perception of the shape of the crater?

The South Pole-Aitken Basin is the largest crater not only on the Moon, but also the oldest and largest visible in the Solar System. Its diameter is estimated at 2,500 km, and its age reaches 4 billion years. The study of the basin is complicated by its considerable size, which is why scientists are still working on determining its shape and exact parameters. However, new data from the Lunar Reconnaissance Orbiter indicate that the previously accepted model for the formation of this crater may be incorrect.

Scientists had previously suggested that the crater was formed by an asteroid impact with an oblique trajectory that caused the crater to be oval in shape, with debris from the impact spreading mainly in one direction from the moon's south pole. However, new studies of more than 200 objects scattered around the impact crater show that the shape of the crater is closer to round, that is, the asteroid could have fallen almost perpendicular to the surface of the Moon. The researchers also found an even distribution of debris around the crater, which makes it easier to access rocks from the Moon's interior. Thanks to this, it will be possible to study more deeply the composition of the satellite's mantle, which is inaccessible due to the lack of erosion.

Analysis of gravity anomalies in the crater area shows that the lunar crust beneath the basin is denser than the surrounding regions, which may indicate the presence of remnants of an asteroid that once created the basin. The obtained results open new perspectives for understanding the formation of the Moon and the processes that influenced the evolution of the early Solar System.

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