Next month, people across the continental United States will have the opportunity to witness a partial or total solar eclipse. However, it is crucial for them to take precautions to prevent eye damage during this rare astronomical event.
On April 8th, the moon will pass between the Earth and the sun, causing a temporary blockage of the sun’s light. This will result in a darkening of the afternoon sky along a path approximately 160 miles wide across Mexico, parts of the United States, and parts of eastern Canada.
Those outside of this path will be able to observe a partial solar eclipse, where only a portion of the sun is obscured by the moon.
To safely view the eclipse, special glasses or a pinhole projector can be used. It is important to note that regular sunglasses or other tools like telescopes should not be used to observe the eclipse even while wearing special glasses.
Here are some key points to keep in mind:
How to select the right eclipse glasses
The only safe way to directly view a solar eclipse is by using glasses specifically designed for this purpose. These glasses should be equipped with an ISO 12312-2 filter to prevent photothermal damage to the retina, as advised by Dr. Nicole Bajic from the Cleveland Clinic Cole’s General Ophthalmology Institute.
Eclipse glasses are significantly darker than regular sunglasses, making them safe for solar viewing.
Failure to take precautions while observing a solar eclipse can result in permanent damage to the eyes, known as solar retinopathy, which affects the retina’s ability to transmit light into electrical signals for vision.
When and how to use glasses
According to NASA, it is only safe to view a solar eclipse directly without glasses during the brief period of totality when the moon completely obscures the sun’s bright face. Before and after totality, eclipse glasses must be worn to protect the eyes.
Totality, when the sun is completely covered, lasts approximately three and a half to four minutes and can vary by location.
For those observing a partial solar eclipse, wearing eclipse glasses throughout the event is essential. Additionally, using tools like binoculars or cameras without solar filters can cause serious eye damage.
Ensuring the safety of your glasses
While NASA does not endorse specific solar viewers, it is recommended to choose reputable options from sources like the American Astronomical Society to avoid counterfeit or substandard products.
If you saved your eclipse glasses from the 2017 event, they can be reused as long as the lenses are undamaged. However, if there are any scratches, holes, or wrinkles on the lenses, it is advisable to purchase new glasses.
Creating and using a pinhole projector
In the absence of proper glasses, a pinhole projector can be made to safely view the solar eclipse without looking directly at the sun. This device captures sunlight through a small hole, projecting it onto a surface to create a safe image of the sun.
To make a pinhole projector, cut a hole in a piece of paper, cover it with aluminum foil, poke a small hole in the foil, and use another piece of paper as a screen for the projected image. Adjusting the distance between the projector and the screen will change the size of the image.
Other household items like a colander or a cereal box can also be used to create a pinhole projector for eclipse viewing.
Alternatively, stand under a shady tree during the eclipse to observe the crescent-shaped shadow cast on the ground.
Source: www.nbcnews.com
