On the 20th of May 2012, the moon will eclipse the sun for the first time in the US this century. Over the course of this particular eclipse, the sun will will not completely disappear, but remain as a ring around the shadow of the moon, tis is called an annular eclipse. The reason for this annular eclipse will be the moon’s position at its most distant point from the sun, thus not being able to completely shadow the sun.
The path of annularity, as the shadow casted on the earth is called for lunar eclipses, is a shadow strip 300 km wide and thousands of kilometers wide, that will only be seen in the northern hemisphere, covering a wide area, from China and Japan through the Pacific Ocean to the US East Coast and middle North America.
During the course of 2012, there’s another solar eclipse forecasted to take place on November 13. This second solar eclipse of the year will be a total solar eclipse, thus the moon will completely shadow the sun, and the ring of fire typical of annular eclipses will not be seen.
Find here a video explaining the 20th may 2012 solar eclipse and its impact on North America: