Picture of Apollo 16 launch Courtesy of NASA

Apollo 16 was launched on April 16, 1972 and took astronauts John Young, Thomas Mattingly, and Charles Duke to the Moon. Their mission was to visit a previously unexplored region of lunar terrain, believed to contain evidence of ancient volcanic activity.

Young and Duke performed three space walks during their stay on the Moon. They set up an science experiment station and collected soil and rock samples with the Lunar Roving Vehicle, first used in the Apollo 15 mission.

Although Apollo 16 returned over 200 pounds of material back to Earth, none of it gave scientists conclusive information about the Moon's geologic history.