The sun's outer atmosphere―the corona—is visible to the eye only at times of a rare total solar eclipse, such as this one shot from Salloum, Egypt on March 29, 2006.  Great equatorial streamers extend a million miles into space and, closer to the sun's edge, intricate polar brushes trace the star's magnetic field lines.  No single exposure can ever  hope to capture the full 10,000:1 brightness range of a total solar eclipse, so this image required 36 hours to blend six separate exposures into one that shows the intricate coronal structure visible to the eye that day.