Gale is a crater, and probable dry lake, at 5.4°S 137.8°E in the northwestern part of the Aeolis quadrangle on Mars. It is 154 km (96 mi) in diameter and estimated to be about 3.5-3.8 billion years old. The crater was named after Walter Frederick Gale, an amateur astronomer from Sydney, Australia, who observed Mars in the late 19th century. Aeolis Mons is a mountain in the center of Gale and rises 5.5 km (18,000 ft) high. Aeolis Palus is the plain between the northern wall of Gale and the northern foothills of Aeolis Mons. Peace Vallis, a nearby outflow channel, 'flows' down from the hills to the Aeolis Palus below and seems to have been carved by flowing water. Several lines of evidence suggest that a lake existed inside Gale shortly after the formation of the crater.
