highlands, lunarThe topographically elevated and more rugged regions of the Moon. They have a higher albedo – and thus appear brighter – than the maria and consist largely of anorthosite, a calcium-aluminum silicate rock. Lunar highland areas include most of the farside and southern part of the nearside of the Moon. Craters are larger and more abundant here than in the maria; this reflects the greater age of the highland crust, parts of which date back 4600 million years to the formation of the Moon. See also Moon rocks; mountains, lunar.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006