Enjoying the night sky above the Grand Canyon while the setting moon gently illuminates the canyon. In the sky the Milky Way appears in the Summer Triangle (formed by three bright stars Deneb, Vega, and Altair) through the constellation Cygnus, Aquila, and Lyra. The Grand Canyon in northern Arizona is the longest canyon on the Earth, a steep-sided gorge carved by the Colorado River steadily in about 17 million year time span. The canyon is 446 km long, ranges in width from about 6 to 29 km and attains a depth of more than 1.6 km (a mile). Date: Nov. 2012