Lunar Volcanism

Data from the Japanese probe now orbiting the Moon suggests the histories of the nearside and the farside might be quite different. Scientists have known for some time that the Moon was internally active at some point. the dark patches we see on the face is volcanic basalt. Now, however, scientists think volcanism endured longer on the nearside than on the farside.

Using data from the Selene Kayuga probe, scientists think volcanism existed on the farside until about 2.5 billion years ago, while on the nearside it lasted until about 1 billion years ago. The standard view has been that lunar volcanism ceased 3 billion years ago.

Nailing down the timeline will likely have to wait until we have actual samples from across the Moon.