On May 10, 2013, the sun experienced what's called an annular eclipse - when the moon moves directly in front of the sun, but doesn't obscure it completely. This leaves a thin, fiery ring, the annulus, visible around the outside. This eclipse was only visible from the South Pacific, along an approximately 100-mile-wide track that traverses Australia, Papua New Guinea, the Solomon Islands and the Gilbert Islands. Other areas in Australia and Indonesia saw a partial eclipse, in which the moon blocks a much smaller region of the sun.
Annular eclipses occur at times when the moon is farther away from Earth, making it appear smaller, and not big enough to completely block the sun. While eclipses have long served as a way of observing the sun's dimmer atmosphere at a time when the bright light of the sun is blocked, annular eclipses don't provide much help with this kind of research, as the glare of the annulus overpowers any chance of seeing the atmosphere.
Eclipse observations take place with special telescopes, as even during an eclipse, one should never look directly at the sun.
This timelapse shows an annular eclipse as seen by JAXA's Hinode satellite on Jan. 4, 2011. An annular eclipse occurs when the moon, slightly more distant from Earth than on average, moves directly between Earth and the sun, thus appearing slightly smaller to observers' eyes; the effect is a bright ring, or annulus of sunlight, around the silhouette of the moon.