May 17, 2012 2:47 PM
LOS ANGELES (AP) - Millions of people in the western United States and some parts of Asia will get to witness the sun transform into a ring of fire.
The event is an annular solar eclipse. It occurs when the moon passes in front of the sun, blocking everything but a bright ring of light.
On Sunday, the late day sun will transform into a glowing ring in northern Arizona and parts of Oregon, California, Nevada, Utah, New Mexico and Texas.
A ring eclipse is not as dramatic as a total eclipse, when the disk of the sun is entirely blocked by the moon. As in a total solar eclipse, the moon crosses in front of the sun, but the moon is too far from Earth and appears too small in the sky to blot out the sun completely.
The last time this type of eclipse was seen in the U.S. was in 1994. This year's solar show offers ringside seats at 33 national parks along the eclipse path including the Grand Canyon.