Geological Chronicle
Located on the northeastern near side of the Moon, Lacus Spei, translated from Latin as the "Lake of Hope," has an official diameter of 76.67 kilometers. The feature lies within the Gauss quadrangle, bordered by the crater Mercurius to the north, Schumacher to the west-southwest, and Zeno to the east-northeast.
The main part of the lake averages about 50 kilometers across, with an arm extending toward the northeast. Its surface shares the low albedo of larger lunar mare features, lightening in hue near the edges. The circular, cup-shaped satellite crater Zeno P is the only interior feature.
The International Astronomical Union officially adopted the name Lacus Spei in 1976.