STS077-728-057 Yauca and Acari River Canyons, Peru May 1996 The dry, canyonlike terrain of the Peruvian coast is visible in this northeast-looking, low-oblique photograph. Clouds cover the western Andes Mountains, the longest mountain system in the world, which began to form 600 million years ago. Uplifted coastal plains deeply grooved the coastal areas, sculpturing deep canyons, some of which extend to the coast. A slow uplift continues to build the Andes, which are rising approximately 4 inches (10 centimeters) each century. Visible are many small canyons and two major ones--the Acari River Canyon (center of photograph) and the Yauca River Canyon to its south. Some irrigation is discernible in both river valleys and near the coast where the rivers empty into the Pacific Ocean. Point Chala appears at the bottom right of the photograph.