| | Lunar mare - Wikipedia, the free encyclopedia |
 | | The dark regions are the lunar mare, whereas the lighter regions are the highlands. |
 | | However, in a reference frame rotating with the Moon, the centrifugal acceleration is exactly equal and opposite to the gravitational acceleration of the Earth. |
 | | Based on data obtained from the Lunar Prospector mission, it appears that a large proportion of the Moon's inventory of heat producing elements (in the form of KREEP) is located within the regions of Oceanus Procellarum and the Imbrium basin, a unique geochemical province now referred to as the Procellarum KREEP Terrane. |
| en.wikipedia.org /wiki/Lunar_mare (859 words) |