Apollo 15 (AS-510) Exploration of Hadley-Apennine RegionApollo 15 was the fourth mission to land men on the Moon. This mission was the first flight of the Lunar Roving Vehicle which astronauts used to explore the geology of the Hadley Rille/Apennine region.
The LRV allowed Apollo 15, 16 and 17 astronauts to venture further from the Lunar Module than in previous missions. Total surface traverses increased from hundreds of meters during earlier missions to tens of kilometers during Apollo 15 and 16 and just over 100 kilometers during Apollo 17.
Hadley Rille is a V-shaped gorge paralleling the Apennines along the eastern edge of Mare Imbrium. The rille meanders down from an elongated depression in the mountains and across the Palus Putredinis (Swamp of Decay), merging with a second rille about 62 miles (100 kilometers) to the north. Hadley Rille averages about a kilometer and a half in width and about 1,300 feet (400 meters) in depth throughout most of its length. Large rocks have rolled down to the rille floor from fresh exposures of what are thought to be stratified mare beds along tops of the rille walls. Geologists were curious about the origin of the Moon's sinuous rilles, and some scientists believe the rilles were caused by some sort of fluid flow mechanism--possible volcanic.Mount Hadley, Hadley Rille and the various Hadley craters in the region of the landing site are named for British scientist-mathematician John Hadley (1682-1744) who made improvements in reflector telescope design and invented the reflecting quadrant--an ancestor of the mariner's sextant. Source: Smithsonian National Air and Space Museum