The GRAIL mission determined the internal structure of the Moon in great detail for nine months during 2012. Armed with this the new information, GRAIL astronomers were able to redefine the sizes of the largest impact basins on the lunar surface.
Despite this oddball moon's many exotic attributes, it actually sports one of the most Earth-like surfaces in our Solar System. Titan may also experience volcanic activity, but its volcanoes would erupt with different ingredients than the molten-rock lava that shoots out from the volcanoes of Earth. In dramatic contrast to what occurs on our own planet, Titan's volcanoes erupt icy water "lava" (cryovolcanism). Titan's entire alien surface has been sculpted by gushing methane and ethane, which carves river channels, and fills its enormous great lakes with liquid natural gas.
Astronomers have known for years that the temperatures of the lunar near-side are higher than those on the far-side. This is because the abundances of the heat- producing elements uranium and thorium are greater on the near-side than on the far-side. In addition, these higher temperatures are a consequence of the fact that most of the volcanic eruptions occurred on the lunar near-side.