The highlight of the last human spaceflight to the Moon occurred on 11 Dec. 1972, with the lunar landing of Apollo 17. After a four-day journey to the Moon, astronauts Eugene Cernan and Harrison Schmitt descended to the lunar surface while crewmate Ronald Evans remained in lunar orbit. Schmitt, the only professional geologist to walk on the Moon, and Cernan landed in the Taurus-Littrow highlands region, an area that offered a unique combination of old and young geologic material. Credit…