Published on: 12 Jul, 2017
On August 21, Southern Alberta will be near the pathway of what some astronomers are calling the “biggest one-day sky event in history”. The first total solar eclipse in our part of the world in 38 years will occur just south of our international border. Whether you choose to travel to the US to experience “totality” or decide to watch the partial eclipse right here at home, you must take precautions with your eyes.
In the Calgary area, for about 2.5 hours on Monday morning, August 21 2017 the moon will partially obscure the sun as the eclipse occurs. Because we will not experience the total eclipse in our area, protective glasses must be worn for the entire duration of the event for those who choose to observe it. Even a small amount of sunlight projecting from around the moon can cause permanent damage to eyesight without protective eyewear. Within the narrow band of totality (happening across several US states) there will be about a 2.5 minute window where the eclipse will be safe to view without glasses. Before and after this window of time protective glasses must be worn.
Only certain glasses are safety-approved for eclipse viewing – dark sunglasses and even most welder’s filters are not safe enough. Please only use approved glasses. NASA has increased the standards required of companies who sell eclipse glasses. The new standard is ISO 12312-2. Please ensure your glasses meet the new requirements for safety.
Prior to using your eclipse glasses, inspect the lenses for signs of scratches or defects (do not use them if any are found). During the eclipse, be sure to put on your eclipse glasses before looking at the sun, then look away from the sun before removing the glasses. Supervise your children to make sure they are wearing their glasses properly as well. NOTE: eclipse glasses are NOT safe to use with binoculars to view a partial eclipse! An approved filter for your particular device must be used if you intend to watch the eclipse through a magnifying device.
By exercising simple precautions we can all safely enjoy this once-in-a-lifetime celestial event!