South Pole Aitken Basin

South Pole-Aitken Basin This LOLA topographic map centers on the South Pole-Aitken (SPA) basin, the largest impact basin on the Moon (diameter = 2600 km), and one of the largest impact basins in the Solar System. The distance from its depths to the tops of the highest surrounding peaks is over 15 km, almost twice the height of Mount Everest on Earth. SPA is interesting for a number of reasons. To begin with, large impact events can remove surficial materials from local areas and bring material from beneath the impact craters to, or closer to, the surface. The larger the crater, the deeper the material that can be exposed. As SPA is the deepest impact basin on the Moon, more than 8 km deep, the deepest lunar crustal materials should be exposed here. In fact, the Moon's lower crust may be revealed in areas within SPA: something not found anywhere else on the Moon.