What major process shaped the Moon's surface, according to its composition?

The major process that shaped the Moon's surface is meteorite impacts. The Moon's surface is covered with a layer of regolith, which is a fine, powdered material created largely by the constant bombardment of meteoroids over billions of years. This impact cratering has resulted in a diverse landscape, featuring many craters of various sizes, from small pockmarks to large basins. Unlike Earth, the Moon lacks significant atmospheric protection, which means that meteoroids can reach its surface without being burned up.

The composition of the lunar surface also supports the idea that meteorite impacts played a critical role in its formation. The Moon features basalts formed from volcanic activity in its early history, but the dominant feature of its landscape today is the result of impacts, not volcanic activity.

Other processes like wind erosion and water flow are virtually nonexistent on the Moon due to its lack of atmosphere and liquid water, reinforcing the conclusion that meteorite impacts are the primary force that has shaped its surface.