'Kevin Fong talks to one of the last two men on the Moon, 40 years after the final Apollo 17 mission blasted off on 7 December 1972.
'As an Apollo astronaut, Harrison Schmitt was special. He was was the only geologist ever to explore the lunar surface.
'The field work Dr. Schmitt did, and the rocks he and his fellow astronauts brought back, revolutionised our understanding of the Moon and the Earth.
'Dr. Schmitt also shares the human experience of running around another planet and explains why he thinks we should go back, and beyond.
'The conversation also features archive recordings of the two Apollo 17 moon walkers, Schmitt and Commander Eugene Cernan talking from the lunar surface and Challenger module to NASA’s mission control in Houston in 1972.' (BBC World Service Discovery podcast).