This image (three combined frames) shows the last total solar eclipse, March 29, 2006. The next one takes place tomorrow. The Exploratorium will Webcast the event live from China. From Science News:
This particular eclipse will sweep across the planet in a slim path that begins in Nunavut, a northern province of Canada, and ends in northern China. So people in parts of Canada, northern Greenland, the Arctic, central Russia, Mongolia and China will be able to witness the seconds-long blackout.
When the moon totally obscures the sun – the moment of totality – the sun's outer atmosphere, called the solar corona, becomes visible. The solar corona reaches temperatures higher than a million degrees Celsius and extends farther than 620,000 miles from the star's surface. Because the sun's surface is brighter than its corona, a solar eclipse is the only opportunity to see the corona with the naked eye.
Total solar eclipse (Science News), Total Solar Eclipse 200 Live from China (Exploratorium)
