The August 2017 solar eclipse offered an incredible opportunity to witness how natural light colors our world. For those outside the path of totality the eclipse was almost imperceptible as our eyes automatically adjust for the changing intensity of the sun = 5% of the sun is still incredibly bright! Until the sun was more than 95% blocked, it was very difficult to see any changes, though the sun did feel less hot. Only with solar eclipse glasses was it possible to observe the moon partially blocking of the sun, without these special glasses the sunny day looked normal. Those lucky enough to be in the path of totality experienced the change from a bright sunny day (sun less than 95% blocked) to a stunning ‘shadow-less sunset’ in the ~2 minutes before the eclipse reached totality. With the sun more than 95% blocked the day suddenly got almost dark (like dusk), the horizon was filled with warm colors, several stars/planets became visible, and the temperature plummeted.
Totality can be viewed without solar glasses as the intensity of the sun drops to safe viewing levels. As photos show, totality is visible as an incredibly bright/crisp white ring around the black moon shadow, with the corona extending out further (wavy lines of gas streaming from the sun’s surface) set against the regular blue/summer sky. The geometry of totality is unique at this moment in history, with the sun ~400x larger than the moon, but also ~400x further from the earth which makes the visible size of the two objects equivalent. As the moon slowly moves further away from the earth, this geometry will change. From a photographer’s point of view, recording this image requires an amazing dynamic range to capture the contrast between the black moon shadow, the bright white light at the moon’s edge, and the modestly intense corona. Your eyes have a greater dynamic range than most any recording equipment so there is no substitute for viewing this event in person.
Totality is a rare event and has inspired humans for centuries. For some great images of eclipse sequence check out the NASA collection. At instant when the sun peaks back out from behind the moon you have the ‘diamond ring’ effect after which it was too bright to view the eclipse without solar glasses. While the entire eclipse cycle lasted more than two hours, all of the visible action occurred in ~six minutes, two minutes before totality, ~2 minutes during totality and two minutes after totality. The drop in temperature lasted longer, as the sun had to regain its intensity and reheat the landscape. The sun is the master clock for all living things, so the birds sang their sunset songs, the crickets chirped and the coyotes (and dogs) howled, a truly awe inspiring experience!