The Grand Prismatic Spring in Yellowstone National Park, photographed by NASA's IKONOS satellite. More here, as well as some conventional aerial shots.
These are all hosted on something called the Chamorro Bible site, of which I can't make heads or tails. It seems to have something to do with Seventh-day Adventist missionaries.
Whatever. If you click around, you'll find other impressive pictures, such as these, of US military transport airplanes.