Harrison Schmitt credits the image to the entire Apollo 17 crew. While on the Moon's surface, Schmitt — the only geologist in the astronaut corps — collected the rock sample designated Troctolite 76535, which has been called "without doubt the most interesting sample returned from the Moon". Among other distinctions, it is the central piece of evidence suggesting that the Moon once possessed an active magnetic field. As he returned to the Lunar Module before Cernan, Schmitt is the next-to-last person to have walked on the Moon's surface. After the completion of Apollo 17, Schmitt played an active role in documenting the
John Young (astronaut) John Young (astronaut) John Watts Young (September 24, 1930 – January 5, 2018) was an American astronaut, naval officer and aviator, test pilot, and aeronautical engineer. He became the ninth person to walk on the Moon as Commander of the Apollo 16 mission in 1972. Young enjoyed the longest career of any astronaut, becoming the first person to fly six space missions (with seven launches, counting his lunar liftoff) over the course of 42 years of active NASA service. He is the only person to have piloted, and been commander of, four different classes of spacecraft: Gemini, the Apollo Command/Service