Ocean of Storms

The Moon's largest dark plain

The Ocean of Storms is the only 'ocean' on the Moon, because it is far bigger than the seas: 2,500 km! Of course it has no water either — it is hardened lava. Many spacecraft have landed here: Luna 9 (the first soft landing), Apollo 12, and recently China's Chang'e 5, which brought Moon soil back to Earth.

The Ocean of Storms (Oceanus Procellarum) is the largest lunar mare, 2,500 km long and 4 million km² in area. Unlike other maria it is not a round impact basin — lava probably rose through a giant system of crustal rifts (GRAIL, 2014). The region is rich in KREEP rocks (potassium, rare-earth elements, phosphorus), and radioactive heating kept volcanism going here longer than anywhere — until 1.2 billion years ago. Landings: Luna 9 (1966, first soft landing), Luna 13, Surveyor 1 and 3, Apollo 12 (1969), Chang'e 5 (2020, returned 1.7 kg of samples).

Fun facts

• Apollo 12 astronauts landed next to the Surveyor 3 probe and brought pieces of it back to Earth.
• The Ocean of Storms is 9 times bigger than Uzbekistan.
• The rocks Chang'e 5 returned are 2 billion years old — lunar volcanoes worked longer than expected.