If you live in the Western part of North America, chances are that you have never ever witnessed an Annular Solar Eclipse - That's when the moon blocks out most of the sun, transforming the outer edge into a spectacular 'ring of fire'. The last time this was visible from the United States was in 1994 - The next? Sunday, May 20th 2012!

The best places to watch this rare eclipse will be Medford,Oregon, Chico,California, Reno Nevada, Albuquerque, New Mexico, and Lubbock,Texas. NASA experts believe that these lucky people will be able to experience the phenomenon for a full 4.5 minutes. The annular will also be visible over the North Pacific, in Southern Japan and Southern China on the morning of May 21st.

Other parts of the Western United States and Canada will be able to view a partial solar eclipse just not, the 'ring of fire'. However, this is better than being on the East Coast, which will miss the entire spectacle, since the sun will have already set, before it all begins.

That's because unlike most celestial events that take place late at night or, in the wee hours of the morning, this one, will occur in the late evening - From 5.30 to 7.30 pm, Pacific Standard Time.

But, just like all solar eclipses, this spectacular event can also be very dangerous. NASA's leading eclipse expert Frank Espenak warns that the ring during annular eclipses can be extremely bright and cause permanent damage to the eye and even blindness, if looked at directly or through telescopes or binoculars not covered with the right solar filters. So be sure to get some before Sunday if you are planning to view the eclipse.

Even safer than that, is looking at it indirectly - Simply use the telescope or binocular to project a magnified image of the 'ring of fire' onto a shaded white piece of cardboard. While this is safe to look at and even take pictures, make sure that the telescope's finder scope or the unused half of the binoculars is covered and most importantly, don't try take a peek through them.

The safest of all however, is to join an event planned by your town or city officials. With just about every national park in the west organizing some kind of viewing event, there is bound to be something nearby.

A solar eclipse occurs when the Moon passes between the Sun and Earth, so that the Sun is partially or totally covered. Solar eclipses can only occur during a new moon, when the moon is between the Earth and the Sun. Whether it will be a total or partial eclipse depends on where the moon is in its orbit. Since the moon's orbit around the earth is not perfectly round but oval, it's distance from the Earth varies from about 221,500 to 252,000 miles. Whenever its orbit brings it closer to the Earth, it appears larger then the Sun, and when the three align, a total eclipse occurs.

Conversely, an annular eclipse occurs when it is further away from the Earth and therefore appears smaller than the Sun. In this case, when the three align, the perimeter of the sun is exposed causing the sun to appear like a 'ring of fire'.

To check if your town or city will be able to witness any part of the 2012 Annular Solar Eclipse go to shadowandsubstance.com.

Resources: Science.NASA.gov, huffingtonpost.com, cbsnews.com,cnn,com