Procellarum

Mare Procellarum, also known as Oceanus Procellarum and commonly referred to as Procellarum, is a vast lunar mare located on the Moon’s near side. It is the largest of the Moon’s maria by area and forms a prominent dark patch visible from Earth. The region lies along the western edge of the near side and is bordered by the lunar highlands to the south and east, with its northern boundary blending into the Oceanus Frigoris and surrounding mare units.

Geologically, Procellarum is a basaltic plain created by ancient volcanic activity. Like other maria, its surface is dominated by solidified lava flows that filled large impact basins early in the Moon’s history. The area is notable not only for its extent but also for its distinctive geochemical signature, particularly the Procellarum KREEP Terrane (PKT), which is enriched in potassium, rare earth elements, and phosphorus. This geochemical province has influenced the composition of surface rocks and the mare’s thermal and magmatic evolution.

Within Oceanus Procellarum are several prominent features, including the Aristarchus region, a notable crater and plateau that stands near the mare’s boundary. The area also contains networks of rilles and other mare-related formations that have been studied through lunar orbiters and landed missions. The Procellarum region has been a focus of interest for understanding the Moon’s volcanic history and crustal evolution, as well as the distribution of KREEP and related materials across the lunar surface.