|The full moon with the great Oceanus Procellarum. In the middle of the ellipse and on the right the bright ray craters Kepler and Copernicus . Above it borders on the Mare Frigoris , on the upper right on the large Mare Imbrium , on the lower right on the Mare Nubium and in the south on the round Mare Humorum .|
|See also Gazetteer of Planetary Nomenclature|
The Oceanus Procellarum ( Latin "ocean of storms") is a very large, irregularly shaped area of the ocean on the moon in the western part of the moon side facing the earth . It got its name from the earlier assumption that its appearance would bring bad weather with the waning crescent .
Oceanus Procellarum is the largest of the "lunar seas" with an extension of 2,500 km in north-south direction and an area of more than 4,000,000 km² . Like all Maria, it was formed by volcanic activity, during which lava and basaltic magma covered the area with a thick, almost flat blanket. Unlike most other Maria, it was not created by an impact , but by overflowing magma from other regions, which is indicated by the irregular border. The lunar crust under the basalt cover does not form an impact basin, but is relatively flat and without mascons .
There are many smaller "seas" and "bays" on its eastern half. In the northeast, Oceanus Procellarum is separated from the large circle of the Mare Imbrium only by a flat transition and the "Lunar Carpathians" , in the southeast from the Mare Nubium by the Montes Riphaeus . In the south it borders on the highlands at Mare Humorum , in the southwest on that of the Grimaldi impact basin . The most conspicuous structures in the Oceanus are - especially when the moon is full - the craters Copernicus , Kepler and Aristarchus surrounded by radiation systems (see picture above right).
Reception in music
In 1967 the composer Paul Dessau wrote an orchestral work entitled Sea of Storms .