NASA Reading the Alphabet From Space

NASA's Earth Observatory has tracked down images resembling all 26 letters of the English alphabet using only NASA satellite imagery and astronaut photography. In this image, the letter 'Y' is for yardangs, elongated landforms sculpted by erosion and similar to sand dunes, but instead comprised of sandstone or siltstone. via NASA http://www.nasa.gov/image-feature/reading-the-alphabet-from-space