How many kilograms of lunar material did Apollo 11 return to Earth?

Apollo 11 returned 21.55 kilograms of lunar material to Earth.

Neil Armstrong and Buzz Aldrin collected rocks, soil, and a contingency sample during their surface excursion in the Sea of Tranquility. The material was sealed and carried home in the lunar module’s ascent stage before being transferred to the command module Columbia.

The samples gave scientists their first substantial opportunity to study material from another world directly. They helped confirm that the Moon’s surface had experienced ancient volcanic activity and intense impact processes.

Apollo 11’s total was much smaller than the combined collection from all six successful landing missions. The entire Apollo program returned about 382 kilograms of lunar rocks and soil, a figure sometimes mistakenly attributed to Apollo 11 alone.