LOS ANGELES, CA (Catholic Online) - Solar eclipses occur when the Moon passes between the Earth and Sun casting its lunar shadow across a narrow path on the ground. For those who live along the path of that shadow, they will see a total solar eclipse. On Sunday, most of the western US, will see a partial solar eclipse, as the moon takes a bite out of the sun, but does not cover it completely. 

The eclipse will begin around 5 pm PDT in the western US and reach maxim around 6:30 pm PDT. It will occur slightly later in the mountain time zone, beginning around 6:30 pm there and lasting for a little over one hour. 

The eclipse of May 20, 2012 is a slightly rare version of an eclipse known as an annular eclipse. Annular is derived from a Latin word, annulus, meaning (ring). This is because the Moon will be farther away from the Earth than usual and will thus appear smaller in the sky, small enough in this case that it will not cover the sun entirely, although it is passing directly in front.

A ring of fire will surround the (apparently) smaller Moon at the moment of maximum eclipse.

Because conditions have to be just right for an annular eclipse to occur, such events are a little more rare than traditional total solar eclipses. 

While most of the western US will see some of the eclipse, those wanting the full experience must be in northern California or the southwestern bit of Oregon. From there, the moon's shadow will sweep across most of central Nevada, southern Utah, northern Arizona, central New Mexico, and will end at sunset in central Texas around Lubbock. 

For anyone viewing the eclipse, no matter where they live, here are a few tips and pointers for safe observing. Keep in mind the sun as a ball of hydrogen gas constantly kept burning by billions of nuclear explosions in its core. When you are looking at the sun, you are looking at the largest nuclear blast in our solar system, ever. If you are not careful, it will blind you.

1.    Don't look! It is never safe to look directly at the Sun with the naked eye, even during an annular eclipse. Only at the maximum of a total solar eclipse can you safely view the Sun for a matter of seconds or minutes. During an annular eclipse, a portion of the Sun is still visible, so direct viewing is still unsafe. 

2.    No sunglasses! Sunglasses do not offer adequate protection, nor do multiple pairs of sunglasses. 

3.    No binoculars or telescopes! Never look at the Sun directly through binoculars or a telescope either. Doing so will cause instant blindness. Professional astronomers can only do this with specialized equipment. Unless you are trained and equipped, you should avoid this kind of viewing. 

4.    Buy special glasses. To view the eclipse safely, you may purchase special eclipse glasses. These are very inexpensive, costing only a few dollars. They are flimsy, and comparable to 3D movie glasses in construction and appearance, but with dark lenses. These allow short-term direct viewing. 

5.    Buy welder's glass. Number 14 welder's glass will allow direct viewing. Note that the glass must be a minimum of 14 in darkness. Combining plates, such as using two number 12 plates, will not protect your eyes. Individual plates are available for only a few dollars or less at welding supply stores. Your local store may have to special order no. 14 glass. You may also buy this online. 

6.    You may also view a projection of the eclipse through a telescope (or binoculars). This may require the use of a special mount and should not be attempted unless you know how to project the Sun safely through a scope. This can be difficult to manage during an eclipse if you have not done it before. Also, the sunlight will heat the telescope, which can be harmful to the instrument.
 
7.    View the reflection of the eclipse in water. Using a large cup or bucket, or even a standing puddle as a mirror, and you can safely view the eclipse.

8.    Use a pinhole projection. The pinhole projection is simply a card with a pinhole through which the sunlight shines onto the ground or another larger card behind it. This effectively projects the image of the eclipse on the card. 

9.    View the eclipse in the shade of a tree. The leaves of trees form thousands of pinhole projections on the ground during an eclipse, a phenomenon that is easily discerned during the event. Simply look at the sunlight on the ground as it filters through leaves on a tree. 

10.    View the event online. This is especially useful if you live where the eclipse is merely partial or unviewable due to cloud cover or location. A number of websites will stream the event live, search online for one that's suitable for your viewing. 

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