The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image of the Petermann Glacier on July 5, 2003. On Greenland, tens of thousands of years of snowfall have settled and solidified into a massive sheet of ice. Each summer, snow retreats briefly at low elevations, and a narrow strip of rocky coastline emerges. As it thins and fractures, sea ice that packed into the mouths of fjords over the winter takes on the look of a mosaic made from blue and white stained glass. Glaciers flowing down from the highland interior become a little slushy, at least on top; turquoise blue pools of melt water dot the surface. These changes are evident in this image.