Monday, August 21, 2017 is the date of the next total solar eclipse to be seen in the US. It has been 38 years since the last total solar eclipse was viewable in the US and it won't occur again until April 8, 2024.
Time of the eclipse will be from 9:13 am to 12:00 noon in the Phoenix area. All of North America will experience a partial eclipse where the moon will cover part of the sun for 2-3 hours. And for those in roughly a 70-mile-wide path from Oregon to South Carolina, halfway through this timeframe, they will experience a total solar eclipse where the moon will completely block the sun for approximately 2 minutes 40 seconds. During the total eclipse, day will seem to turn into night and a hidden solar corona (the sun's outer atmosphere) will be visible, which is supposed to be an awesome sight! This solar corona will not be visible for those viewing a partial eclipse.
Look up the time to view the eclipse for any location here: Eclipse Calculator
Viewing the sun at any time other than sunrise or sunset, when the sun is above the horizon without proper eye protection can lead to vision loss. This includes viewing the sun during a partial eclipse. After only a few seconds of viewing the sun there is temporary bleaching of retinal tissue and in as little as 1 minute permanent damage begins to take place in the retinal tissue. Various structures of the eye filter out various wavelengths of light; however the eye doesn't filter out harmful UV-A and other wavelengths so they pass through the eye and are absorbed by the photoreceptors and retinal pigment epithelial cells in the retina causing permanent damage making them unable to function. This damage to the retinal cells is called solar retinopathy and results in permanent loss of vision.
Initial symptoms one may experience from solar retinopathy can include blurred vision, a central area of vision that is missing, abnormal color vision, distortion of images, increased light sensitivity and headache.Ways you can safely view the eclipse without damaging your eyes.
1. Purchase specially made “eclipse glasses” or other ISO-certified filters. They must be certified as meeting international standard ISO 12312-2:2015 (this should be printed on the glasses).
A few places you can purchase these eclipse glasses:
- Celestron or other astronomy retailers.
- Rainbow Symphony.
- American Paper Optics.
- Thousand Oaks Optical.
2. You can view the eclipse through No. 14 welder's glass – this is the darkest shade of welder's glass available and the ONLY one that is safe to view an eclipse.
3. Special solar filters designed for telescopes, binoculars and cameras – these must be mounted on the front of the device you are viewing through and are generally quite expensive. Note: you should not look through a telescope, binoculars or a camera without a proper solar filter on it EVEN IF YOU ARE WEARING ECLIPSE GLASSES.
4. Pinhole camera or projection – with this method you want to remember to view the projected image through the pinhole – DO NOT LOOK THROUGH THE PINHOLE AT THE ECLIPSE. To find out how to make your own pinhole camera, you need look no further than the internet for various designs. If you don't have time to make your one, you can stand with your back to the sun and cross the outstretched, slightly open fingers of one hand over the outstretched, slightly open fingers of the other. Then you can look at your hands' shadow on the ground. The little spaces between your fingers will project a grid of small images on the ground, showing the sun as a crescent during the partial phases of the eclipse.
- look directly at the sun without eye protection, even briefly
- use sunglasses, photographic film, neutral density filters, smoked glass or other materials as these will not filter out the proper wavelengths of light that damage the eye.
If you want more information, you may wish to check out the following websites:
- Perkins Observatory
- Great American Eclipse
- American Astronomical Society
- Sun-EarthDays Animation Video