If you have been lucky enough to fly in an airplane, you know the world down here looks very different from up there.
Mountains look like wrinkled drapery.
Riverbeds look like jagged scratches on the surface. Farm land looks like a crazy quilt of greens, browns, and yellows. The view from up there tells us a lot of what Earth is all about. Then we could see not only the shape of coastlines and extent of land and water masses, but also the height of mountains and the depth of valleys. The National Imagery and Mapping Agency of the U.S. Department of Defense, along with NASA and the Jet Propulsion Laboratory, are making the most detailed and accurate topographic map ever of almost the whole world.