Picture of Apollo 16 launch Courtesy of the 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 the lunar highlands, a previously unexplored region believed to contain evidence of ancient volcanic activity.

Young and Duke landed in the Descartes Highlands and visited several nearby craters in three EVA's during their stay on the Moon. They also set up an science experiments station and collected soil and rock samples with the Lunar Roving Vehicle, first used in the Apollo 15 mission.

Although Apollo 16 brought over 200 pounds of material back to Earth, none of it confirmed scientists' theories about the Moon's geologic history.