Lunar Far Side Highlands
This image, taken by the advanced Moon Imaging Experiment (AMIE) on board SMART-1, shows a highly eroded highland area on the lunar far side, close to the equator. AMIE obtained this image on 1 January 2006, at a distance of 1483 kilometres from the surface, with a ground resolution of 134 metres per pixel. The imaged area is centred at a latitude of 4.2° South and longitude 98.4° East.
This image shows a highly eroded highland area on the lunar far side. The destruction of earlier craters by subsequent impacts makes many craters nearly unrecognisable.
After the first lunar missions orbited the Moon, it was discovered that unlike the near side, the far side is lacking large lava plains, or maria. The far side is mainly composed of heavily cratered highlands, while only very small areas contain smooth lava plains.
The reason for this difference between near side and far side is not exactly understood. One possibility is that the tidal pull of the Earth on the Moon is responsible for the dichotomy.
The modelling of previous topography and gravity measurements indicates that the Moon's solid crust is thinner on the near side. As a consequence, large impacts could excavate the crust more easily on this side, and so lava had an easier way to flow out and create maria formations.
1 January 2006