Vallis Alpes: The Alpine Valley
hen you think about the Moon, certain features spring to mind. There are craters, the gaping holes left behind when huge chunks of asteroid came hurtling in from space and slammed into the Moon, blasting pits out of the surface. Then there are the lunar seas, or maria, which are vast plains of dark, ancient lava that once flowed over the Moon’s surface, slopping over and
