Geological Chronicle
Lacus Aestatis, translated from Latin as the Lake of Summer, is situated in the southwestern highlands near the western limb of the Moon. The feature consists of two smooth, interconnected patches of lunar mare with a combined surface area of approximately 400 square kilometers. Originally named Mare Aestatis, the International Astronomical Union formally adopted its current designation as a lacus during its 1970 convention.
The northwestern segment of the lake lies east-southeast of the crater Rocca, enclosed within the rim of satellite crater Rocca A. The southeastern segment extends as an elongated, irregular patch stretching north to south, with its southern extremity positioned roughly one crater diameter northwest of the flooded crater Crüger. Across both segments, the regional feature spans a diameter of 86.39 kilometers.
Crater count measurements yield an estimated basalt age of 3.50 billion years, establishing that volcanic activity inundated these highland depressions during the Imbrian period.