How To View A Solar Eclipse

Solar eclipses are rare, photogenic phenomena that occur, on average, once every two years. To witness totality (the point in which the sun is completely obscured) is a once-in-a-lifetime occurrence for most people that are lucky enough to witness one at all. Unlike lunar eclipses, solar eclipses take place in a smaller range of locations. Therefore they are harder to observe.

What Is A Solar Eclipse?

In simpler terms, a solar eclipse is the event in which the moon's shadow falls upon the Earth's surface. The moon's shadow can fall in three different variations. When only the moon's penumbra (light portion of the shadow) falls on the Earth, a partial eclipse occurs. When the moon's umbra (darkest portion of the shadow) falls on the Earth, a total eclipse occurs. When the moon is at apogee, the farthest point in its orbit from Earth, the umbra does not stretch all of the way to the Earth's surface. In this case, an annular eclipse takes place. The terminology derives from the observation that the sun forms an annulus when covered by the moon during this type of eclipse.

Why Don't Solar Eclipses Occur Every Month?

While it seems that the moon would have a chance of passing in front of the Sun in relation to Earth each month, this is not the case. The moon's orbit is slightly tilted in relation to Earth's orbit around the sun. It is only at the points in which these planes intersect (the orbital nodes) that an eclipse can occur. The moon needs to be at one of the two orbital nodes during either new moon (for a solar eclipse to occur) or full moon (for a lunar eclipse to occur).

Where and When To View Solar Eclipses

Solar eclipses are very site-specific in terms of how much obstruction you will be able to witness. Online charts and animations are available to see the locations and times at which your location will be under the most shadow. For eclipse enthusiasts, and other intrigued persons wishing to maximize the duration of totality viewing, travel is an option. Plan to visit a location designated directly in the path of totality. Of course, the funds to do so are not available for most wishing to watch, so an area free of trees will do just fine.

Eye Protection

When viewing a solar eclipse, protecting your eyes should be your first priority. The hands-down safest way to observe a solar eclipse that will surely protect your eyes is to construct a pinhole viewer (much like a pinhole camera, only that it isn't a camera). They are cheap and easy to make. Instructions are widely available.

If, however, you wish to directly look at the Sun (which is not safe, no matter how much reflective material is placed between it and your eyes), then there are several options available. Scientific supply stores often carry "solar eclipse viewing glasses", which serve the exact purpose you would expect. They do not protect yours eyes fully, but are a cheap alternative to other forms of protection such as select welding glasses.

What To Expect To See

If the eclipse you are planning to watch is only partial, you will see a small "bite" is taken out of the sun, and subsequently returned. It will look like a crescent moon combined with the brightness of the sun. Partial eclipses aren't nearly as exciting as total eclipses.

Total eclipses are a rarer but more enjoyable experience. As with partial eclipses, you will see a small "bite" taken out of the sun, that grows larger by the minute. Approaching totality, the sky will become noticeably darker, and the air will cool down by a few degrees. Immediately preceding and proceeding totality, small beads of light will shine through irregularities and canyons on the moon's surface. During totality, the sun's surface will be completely obscured by the moon, and the sun's corona will be visible surrounding the moon. The sky will appear as it would during twilight; some planets and bright stars will be visible despite the fact that it is daytime. Totality can range from mere seconds to several minutes. It is safe to view the eclipse without protection at this time. Be careful, because as soon as the sun's light returns, so does the danger of watching without protection!

Solar eclipses are exciting, unique opportunities that everybody should have the chance to witness at some point in their lifetime. I encourage everyone to make an effort to follow the above guidelines so as to not ruin their experience for any reason. Happy viewing!