Apollo 15 astronauts Dave Scott (right) and Jim Irwin (left) received geology training along the rim of the Rio Grande Gorge. The landing site for Apollo 15 was Hadley Rille located along the rim of Mare Imbrium. The Rio Grande Gorge was considered the closest terrestrial analogue to Hadley since both were over 100 km wide, greater than 1 km in width and over 200 m deep. On the moon Jim Irwin is seen digging a trench to sample lunar regolith.