What is believed to have caused the dust covering the Moon's surface?

The dust covering the Moon's surface, also known as lunar regolith, is primarily believed to have been caused by meteoroid impacts. This is due to the Moon's lack of atmosphere, which means there are no weathering processes like wind or water erosion to wear down the surface. Instead, when meteoroids collide with the Moon, they create craters and displace material, grinding up the surface rock into fine dust and regolith.

Over billions of years, countless impacts from various sizes of meteoroids have layered the Moon's surface with this material. Each impact not only creates craters but also contributes to the ongoing process of regolith formation, resulting in the characteristic dusty appearance of the Moon. Therefore, the understanding of the lunar surface is closely tied to the history and frequency of these meteoroid impacts, making this the most widely accepted explanation for the presence of dust on the Moon.