Sunday, March 22, 2009

Terrae



My North Pole...


My South Pole...



The lighter-colored regions of my surface are called Terrae, or more commonly just highlands,since they are higher then most of the mare of my surface. Several prominent mountain ranges on the near side are found along the periphery
of the giant impact basins, many of which have been filled by mare basalt. These are believed to be the surviving remnants of the impact basin's outer rims In contrast to the Earth, no major lunar mountains are believed to have formed as a result of tectonic events.

From images of my terrae taken by
the Clementine mission in 1994, it appears that four mountainous regions on the rim of the 73 km-wide Peary crater at my north pole remain illuminated for the entire lunar day. These peaks of eternal light are possible because of the Moon's extremely small axial tilt to the ecliptic plane. No similar regions of eternal light were found at my south pole, although the rim of Shackleton crater illuminated for about 80% of the lunar day. Another consequence of my small axial tilt is regions that remain in permanent shadow to you on earth, at the bottoms of my polar craters.