The book “Getting a Feel for Lunar Craters” features tactile diagrams of the lunar surface.

GREENBELT, Md., Sept.

The moon was bombarded by two distinct populations of asteroids or comets in its youth, and its surface is more complex than previously thought.

GREENBELT, Md., April 16 /PRNewswire-USNewswire/ -- As the solar wind flows over natural obstructions on the moon, it may charge polar lunar craters to hundreds of volts, according to new calculations by NASA's Lunar Science Institute team. (Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO) Polar lunar craters are of interest because of resources, including water ice, which exist there.

Shortly after the Moon formed, an asteroid smacked into its southern hemisphere and gouged out a truly enormous crater, the South Pole-Aitken basin, almost 1,500 miles across and more than five miles deep.