Satellite radar topography image of a portion of Central America. Due to persistent cloud cover, obtaining conventional high-altitude photos of this region is extrordinarily difficult. Radar's ability to penetrate clouds and make 3-D measurements allowed scientists to generate the first complete high-resolution topographic map of the entire region. All of Guatemala, Belize, El Salvador, and Honduras are visible on this image, as well as a considerable portion of southern Mexico (the Yucatan Peninsula). Image courtesy of NASA/JPL/NGA.