Serenitatis Basin

The Serenitatis Basin, also known as Mare Serenitatis, is a large, flat, dark plain on the Moon. The name "mare" is Latin for "sea," but these features are actually vast basins filled with solidified lava flows, not water. They are characterized by craters, ridges, and valleys called rilles.1

Maria are the largest topographic features on the Moon and are visible from Earth. They are composed of basalt, formed from ancient lava flows, and their surfaces are covered in a layer of pulverized rock and dust called regolith, created by billions of years of meteoroid bombardment. The basins themselves formed about 3.9 billion years ago from massive impacts, and subsequent volcanic activity flooded these areas with magma. The Taurus-Littrow Valley, where the Apollo 17 mission landed, is located within the ramparts of the Serenitatis Basin impact structure.12