Highlands and Mare landscapes on the Moon
European Space Agency
26 May 2006
These two images, taken by the advanced Moon Imaging Experiment (AMIE)on board ESA’s SMART-1 spacecraft, show the difference between lunarhighlands and a mare area from close by.
The first image, showing highlands, was obtained by AMIE on 22 January2006, from a distance of about 1112 kilometres from the surface, with aground resolution of 100 metres per pixel. The imaged area is centredata latitude of 26? South and at a longitude of 157? West.
The second image, showing a mare, was taken on 10 January 2006, from adistance of about 1990 kilometres and with a ground resolution of 180metres per pixel. The geographical coordinates of the area are 27.4?North latitude and 0.8? East.
Already when looking at the Moon with the naked eye, it can be seenthatthere are bright and dark areas on its surface. Centuries ago, the darkareas were called ‘maria’, presumably assuming that the observer wouldbe seeing water oceans. Today we know that there is no liquid water onour satellite. However, telescopic observations showed that the mariaare very flat, and are very different from the so-called highlands. Thehighlands are heavily cratered and mountainous.
We have learned that the maria are relatively young areas on the Moonwhich were generated after very large impacts penetrated the crust ofour Moon and excavated basins. During later volcanic episodes, liquidmagma came to the surface and filled these basins. When it cooled downand solidified, it formed the large flat areas we can still see now. Asthis happened in comparatively recent times, the number of impactcraters is far less than in the highland areas.
From the two AMIE images it is possible to see how highlands present avery irregular topography and many craters, while the mare area iscomparatively flat and shows a much smaller number of craters.
For more information:
Jean-Luc Josset, SPACE-X Space Exploration InstituteEmail: jean-luc.josset @ space-x.ch
Bernard H. Foing, ESA SMART-1 Project ScientistEmail: bernard.foing @ esa.int