Apollo 17 crew at Tracy's rock. US astronaut Dr Harrison Schmitt and a lunar rover, either side of Tracy's rock. Schmitt, is near the spot where he discovered orange lunar soil. Schmitt, a geologist, and fellow astronaut Eugene Cernan landed on the Taurus-Littrow region of the moon on 11 December 1972, and spent 75 hours on the surface. Apollo 17 was the last Apollo mission, and Schmitt and Cernan are the last people to have walked on the Moon. Courtesy of NASA.