How does the complete lack of volatiles in lunar rocks support the impact theory of the Moon's formation?

The complete lack of volatiles in lunar rocks supports the impact theory of the Moon's formation by suggesting that the Moon was formed from the debris of a colossal impact between the early Earth and a Mars-sized body. This high-energy collision would have caused extreme temperatures, leading to the evaporation of volatile compounds. Consequently, the Moon's composition reflects this high-temperature environment, lacking the volatiles typically found in Earth rocks, further reinforcing the impact hypothesis.