In the first data gathered from the surface of the moon in decades, China's Yutu probe has returned data in the way of radar images that show evidence of enormous lava floods in the moon's past.
Around 35m to 50m below the moon's surface scientists found what they interpreted as a layer of lunar regolith that had been buried beneath flows of lava. Regolith is the lunar dust found on the surface of the moon, and the evidence suggests that the surface formed very early on in the moon's history, only to later be swallowed up by lava.
Unlike the Earth, our moon has no volcanic activity, but that wasn't always the case. Between 3-4 billion years ago, the moon's surface was volcanically active, and the moon's "seas" are actually the result of this volcanic activity. The dark swaths of the moon's surface seen from Earth were initially thought by early astronomers to be oceans of water, but are in fact basalt.
Once the moon's core cooled completely, volcanic activity ceased. While the moon may not be volcanically active, other bodies in our solar system such as Jupiter's moon Io, are still actively spewing magma. Hydrothermal activity on