Plum Crater

Photograph courtesy NASA

Apollo 16 lunar module pilot Charles Duke collects samples near the rim of Plum Crater, a 33-foot-deep (10-meter-deep) depression on the moon's surface. Launched on April 16, 1972, Apollo 16 was the fifth mission to land men on the moon. The United States plans to return humans to the moon by 2020 and eventually build a lunar staging point for human flight to Mars and beyond.