Five third stages of rockets of the Apollo program form the heaviest pieces. While mankind has left over 170,000 kg of Earth on the Moon, only 382 kg of the Moon has been returned to Earth by Apollo and Luna missions.
^ abcdefghijkl Spacecraft was in lunar orbit but is assumed to have decayed from orbit and crashed into the moon, location unknown.
^ abcdef The ascent stage of Apollo 10 was commanded to fire its engine, left lunar orbit and entered solar orbit. The ascent stage of Apollo 11 was left in orbit. Its orbit decayed and it crashed onto the moon, location unknown. The Apollo 16 ascent stage failed to crash into moon when commanded. It decayed from orbit at a later date and also crashed at an unknown location. The ascent stages of the remaining successful missions (Apollo 12, 14, 15, and 17) were each crashed onto the moon deliberately. Apollo 13's complete Apollo Lunar Module burned up in Earth's atmosphere after having served as a lifeboat during the aborted mission.
^ abcLuna program sample return mission; mass listed is for both ascent and descent stages, though only the descent stage was left on the moon.
^ Lander and rover weighed 1814 kg; the rest assumed to have decayed in orbit and impacted the moon.
^ Was injected into lunar orbit in 1990, assumed to have decayed from orbit.