Tuesday, November 5, 2019

Safely Viewing Solar Eclipses

Safely Viewing Solar Eclipses Solar eclipses are among the most dramatic celestial events anyone can witness. They give people a chance to witness parts of the Suns atmosphere they otherwise never get to see. However, looking directly at the Sun can be hazardous and viewing solar eclipses should only be done with safety measures firmly in place. Its worth taking the time to learn how to view these spectacular events without harming ones eyes. For many people, theyre a rare event and worth taking the time to understand how to view safely.   Why Take Precautions? The most important thing to remember about solar eclipses is that looking directly at the Sun at any time is unsafe, including during most eclipses. It is only safe to do so during the few brief seconds or minutes of a total  solar eclipse  when the Moon blocks the light from the Sun. At any other time, viewers need to take extreme precautions to save their eyesight. Partial eclipses, annular eclipses and the partial phase of a total eclipse are never safe to view directly without taking precautions. Even when most of the Sun is obscured during the partial phase of a total solar eclipse, the portion that is still in sight is very bright and can not be viewed without eye protection. Failure to use appropriate filtration may result in permanent eye damage or blindness.   Safe Ways to Gaze One safe method of viewing a solar eclipse is to use a Pinhole Projector. These devices use  a small hole to project an upside-down image of the Sun onto a screen located a half-meter or more beyond the opening. A similar view can be created by interlacing the fingers of both hands and allowing the light to shine through to the ground below. Its also very safe to direct the Sun through the large end of an amateur-type telescope and allow it to project out  of the eyepiece onto a white wall or piece of paper. NEVER LOOK THROUGH THE TELESCOPE unless it has a filter, however!   Filters Never use a telescope to look at the sun without a proper filter. This is especially important if someone is using a telescope to photograph the event. Both eyes AND cameras can be harmed without proper filters attached. Filters can also be used to look directly at the sun, but use caution. People can use welders goggles with a rating of 14 or higher, but no one should use them to look through binoculars or a telescope. Some telescope and camera manufacturers sell metal-coated filters that are safe for viewing the Sun. There are also specialty glasses which can be purchased for eclipse viewing. These can often be found advertised in astronomy and science magazines. People have often remarked that  looking at the Sun through a CD is safe. Its not. NO  one should even think about doing so. Its important to stick to products that are marked safe for eclipse viewing. Its important to always be careful when using filters, glasses, or pinhole projection during the partial phases of a total eclipse. People should  only look for a moment before looking away. Tiny holes in the filters can still subject a persons eyes to possible damage if viewed for extended periods.   How to View During Totality   The moments during a total eclipse when the Moon is completely obstructing the Sun are the only safe times that people can look directly at an eclipse without eye protection. Totality can be very short, only a few seconds up to a few minutes. At the beginning and end of totality, the last stray rays of the Sun can cause some harm, so its best to keep the eye protection in place until the so-called diamond ring has flashed. Thats the last bit of sunlight passing between the peaks of the lunar mountains. Once the Moon moves completely in front of the Sun, then its safe to remove eye protection.   Close to the end of totality, another diamond ring appears. Thats a great signal that its time to put the eye protection back on. It means the Sun will soon be slipping back into view, in all its fiery fury.   Misconceptions about Eclipses Every time theres a solar eclipse, wild tales start to circulate about them. Some of those stories are based on superstitions. Others are based on a lack of understanding of eclipses. For example, some schools locked their children inside during eclipses because school administrators were afraid that harmful rays from the Sun would hurt the students. There is nothing about sunbeams that make them different during an eclipse. Theyre the same sunbeams that shine all the time from our star. Of course, teachers and administrators should allow kids to view an eclipse, but that means they need to be trained in safety procedures. During the total eclipse of August 2017, some teachers were too afraid to learn the procedures, and stories did circulate of kids being forbidden to witness one of these amazing sights. A little scientific understanding would have gone a long way toward providing a wonderful experience for the kids who were in the path of totality.  The most important things to r emember are to learn about eclipses, learn to view safely, and above all - enjoy the view!    Edited and updated by  Carolyn Collins Petersen.

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