Geological Chronicle
Lacus Tenebrarum, named from the Latin word for darkness, is a level area of the lunar surface near the south pole. The feature formed when it was inundated by flows of lava, leaving a plain with a lower albedo than the surrounding ground. Because of its location near the pole, sunlight hits the plain only obliquely.
Measuring 85 kilometers in diameter, Lacus Tenebrarum lies between the prominent crater Drygalski and the south pole. It is situated adjacent to the small crater Ibn Bajja, bounded by Cabeus crater to the east and Kocher to the west. The International Astronomical Union officially named the feature on August 28, 2025.