Mare Moscoviense is a lunar mare that sits in the Moscoviense basin. It is one of the very few maria on the far side of the Moon. Like Mare Marginis, this mare appears to be fairly thin. However, it is clearly centered within a large impact basin. It is also much lower than either the outer basin floor or the farside highlands.
Mare Moscoviense
Composite image of the far side of the Moon. Mare Moscoviense is visible in the upper left quadrant.
Mare Moscoviense from Lunar Orbiter 5, clearly showing the extent of the basin in which the mare lies.
Mare Moscoviense from Apollo 13
The lunar maria are large, dark, basaltic plains on Earth's Moon, formed by lava flowing into ancient impact basins. They were dubbed maria by early astronomers who mistook them for actual seas. They are less reflective than the "highlands" as a result of their iron-rich composition, and hence appear dark to the naked eye. The maria cover about 16% of the lunar surface, mostly on the side visible from Earth. The few maria on the far side are much smaller, residing mostly in very large craters. The traditional nomenclature for the Moon also includes one oceanus (ocean), as well as features with the names lacus ('lake'), palus ('marsh'), and sinus ('bay'). The last three are smaller than maria, but have the same nature and characteristics.
Ancient rift valleys – rectangular structure (visible – topography – GRAIL gravity gradients) (1 October 2014)
Ancient rift valleys – context.
Ancient rift valleys – closeup (artist's concept).
Irregular mare patch – evidence of young lunar volcanism (12 October 2014)