NASA released a photo taken by its Solar Dynamics Observatory of a whip-like solar filament extending more than half a million miles above the sun\'s surface. Such filaments are cooler clouds of solar material that are held above the sun\'s surface by unstable magnetic forces, NASA said in a release Friday. The filament, seen as a darker strand in the image, has been in view for several days, NASA scientists said. The filaments, huge loops of glowing gases, can reach heights of hundreds of thousands of miles above the sun\'s surface, they said.