Near first quarter, the Moon seems to grow mountains. Low sunlight casts long shadows across the lunar Apennines, making the range stand out in binoculars. Apollo 15 landed at the range’s edge and explored its foothills.

Montes Apenninus runs roughly 600 km along the rim of Mare Imbrium, with peaks rising more than 5 km. Near first quarter, the range lies close to the terminator, where low-angle sunlight casts long shadows and brings the terrain into sharp relief. Apollo 15 landed in the Hadley–Apennine region, and its crew used the first Lunar Roving Vehicle to reach the lower slopes of Hadley Delta.