The Stunning Astrogeology of the Apollo Missions

pollo 15 astronauts Jim Irwin (right) and Dave Scott examine the interior of the Rio Grande Gorge from the west rim during a field traverse. Credit: NASA

Neil Armstrong almost made a mistake. He had found an interesting rock sticking out of a formation. Curious to see what the rock was made of, he needed to examine its interior more closely. So he reached for his hammer and took a swing.