Library Columns Library News Mary Beth Isaacson

When the Sky Goes Dark: The 2017 Eclipse By Mary Beth Isaacson

Mary Beth Isaacson
by Mary Beth Isaacson

Why is the August 21, 2017 eclipse so special? For one thing, it’s a total eclipse, meaning that the sun will be completely obscured by the moon. This is the rarest type of solar eclipse, occurring once every 18 months. There are several eclipses every year, but most of the time the sun is only partly obscured. The 2017 eclipse is also unique because it will be visible from such a large portion of the United States. The last time Americans got a total eclipse was in 1991, and that was only visible in Hawaii. Eclipses can be predicted decades in advance, and NASA keeps track of all this information on their website. The next total eclipse won’t be until 2019, and it will only be visible from the South Pacific, Chile, and Argentina.

Perhaps the 2017 eclipse will convert you into an umbraphile, a person who travels to see eclipses. Modern technology has made this hobby much easier, but even in the Victorian period umbraphiles found a way. In 1878, three intrepid scientists traveled to the Wild West so they could catch that year’s total eclipse. The most famous was Thomas Edison, fresh from patenting the phonograph, who had designed a device for measuring infrared radiation. Edison had already been dubbed “The Wizard of Menlo Park,” and was accompanied by reporters the entire way.

American EclipseLess well known is Maria Mitchell, professor of astronomy at Vassar College, discoverer of a comet, and one of the first professional woman scientists. Mitchell carried out an independent expedition to observe the eclipse, bringing a group of female students with her. The other 1878 umbraphile is the asteroid hunter James Craig Watson, renowned during his day but almost forgotten now, possibly because his eclipse project was to discovery the hypothetical (and nonexistent) planet Vulcan. These stories are told in David Baron’s fabulous new book American Eclipse.

If you’d like to read about the history of eclipses, check out Tyler Nordgren’s Sun Moon Earth. This excellent book illustrates how eclipses went from being feared omens of doom and disaster to scientific phenomena to tourist attractions. In addition to the historical context, Nordgren, who is a professor of astronomy physics, includes a reader-friendly explanation of the scientific and mathematical principles behind eclipses. He’s also an avid umbraphile, and one chapter is dedicated to upcoming eclipses, including this year’s.

Visit NASA’s website,, for tons of information about eclipse science, safety, and activities. You can download printable projectors for safe viewing, or build your own solar viewer. NASA will be livestreaming the eclipse from 12 to 4 pm on Monday, which you can watch on their website or in their app. That’s a great way to view it safely, and you won’t have to worry about the weather.

This total eclipse is the first to cross the continental United States in decades. But you won’t have that long to wait for the next one. In seven years, on April 8, 2024, we’ll get another chance, with about 60 percent totality in Florida. And on August 12, 2045, Highlands County will be one of those lucky places right in the center of the action, for the first time since 1918. I’m already looking forward to it!