Credit: NASA

NASA has released radar pictures of the Moon's south polar region — the best ever, with a resolution of 40 metres, showing up the steep slopes and rugged topography (see right).

Taken using the Goldstone Solar System Radar facility in California's Mojave Desert, the pictures could help NASA to find smooth, flat landing areas for future rovers, or suitable spots for a lunar base. The south polar region is of particular interest because some areas, particularly those deep inside craters, are in perpetual shadow and may contain permanently frozen water that could be used as a resource.

But the Goldstone pictures, released on 27 February, do nothing to resolve the debate about whether there is water ice buried beneath the surface because the radar wavelengths used (3 centimetres) do not penetrate the surface well and an analysis of the polarization of the returning signal wasn't performed. Scientists hope that the Lunar Reconnaissance Orbiter, scheduled to launch later this year, will settle the ice question.