Check out this animation below @: http://upload.wikimedia.org/wikipedia/commons/2/28/SE2012May20A.gif

Get Ready for the first Solar Eclipse of the 20th Century for the Continental USA (western USA).

You’ll be able to see video and pictures at: http://www.nasa.gov/sunearth

During an annular eclipse the moon does not block the entirety of the sun, but leaves a bright ring of light visible at the edges. For the May eclipse, the moon will be at the furthest distance from Earth that it ever achieves – meaning that it will block the smallest possible portion of the sun, and leave the largest possible bright ring around the outside.

Read more: http://www.nasa.gov/mission_pages/sunearth/news/eclipse-2012.html