On Aug. 21, 2017, the moon will ride its elliptical orbit precisely between the Earth and the sun, plunging the land below into the crepuscule of a total solar eclipse.

Beginning at around 10 a.m. Pacific Time, the dark path of totality will sweep northwest to southeast across the United States, casting its eerie gloom upon Western towns such as Madras, Ore.; Rexburg, Idaho; and Casper, Wyo. The sky will turn violet; shadows will sharpen; pigeons will roost; and owls will take wing. Millions of umbraphiles—eclipse chasers—will crane their necks to witness more than two minutes of lunar ecstasy, transfixed by an occluded sun that science writer David Baron describes as “an ebony pupil surrounded by a pearly iris … the eye of the cosmos.”

Although partial solar eclipses and lunar eclipses are relatively common, total solar eclipses are rarer beasts: When totality last traversed the entire width of the continental U.S., Woodrow Wilson was struggling to negotiate an end to World War I. Baron, himself a devoted umbraphile—you might call him a lunatic—has pursued the phenomenon to Germany, Australia and the Faroe Islands. His new book, American Eclipse, chronicles an instance much closer to home: the shadow that sped from Montana to Texas in 1878, perhaps the most significant total solar eclipse in the country’s history.

For much of the 19th century, the young United States was a second-rate nation, scientifically speaking, shrouded by what one astronomer deemed a “period of apparent intellectual darkness.” The 1878 eclipse promised to lift that metaphorical blackness by supplying literal dusk: Under the moon-dimmed Rocky Mountain sky, American scientists would have the opportunity to seek new planets, study the sun’s outer atmosphere, and even deduce its chemical composition. Researchers leapt at the chance to help America “fulfill its responsibility as an enlightened member of the global scientific community”—and, in the process, gain personal glory.

Westerners know Baron from his first book, The Beast in the Garden, which documented—some would say sensationalized—a series of cougar attacks in Colorado. In American Eclipse, the fiercest beasts are the scientists competing to document the astronomical anomaly. Baron introduces us to James Craig Watson, an astronomer with a Jupiter-sized ego who’s convinced that the eclipse will help him discover an unseen hypothetical planet called Vulcan. We meet Cleveland Abbe, a meteorologist, known charmingly as “Old Probabilities,” who persists in eclipse-watching at Pikes Peak despite a near-fatal case of high-altitude cerebral edema. And then there’s a young inventor named Thomas Edison, eager “to demonstrate that he was a scientist and no mere tinkerer” by measuring the heat of the sun’s corona with a zany (and ultimately failed) invention called the tasimeter.

Amid all this scientific machismo, the book’s most sympathetic character is Maria Mitchell, an astronomer and suffragette intent on demonstrating the equal abilities of women. At the time, certain pseudo-academics posited that “higher education caused a girl’s body—especially her reproductive organs—to atrophy.” To debunk this repugnant theory, Mitchell dispatched a cohort of “lady astronomers” to Colorado to study the eclipse and provide “a kind of political theater, promoting social change.” Mitchell’s mission succeeded—one newspaper called her squad “a conspicuous example of the power and grasp of the feminine intellect”—though the sexual-harassment scandals that roil modern astronomy prove that true equality still eludes the field.

American Eclipse’s most vivid character, though, is the fledgling West itself. In 1878, the region lingered in a kind of limbo: civilized enough that you could journey to Wyoming in a railcar hung with chandeliers, wild enough that your train stood a considerable risk of being boarded and cleaned out by bandits. The citizens of burgeoning Denver—a town that “aspired to elegance, even enlightenment”—were particularly desperate to prove their city’s worth to snooty East Coast scientists. As one local boasted to a visiting Englishman, “Sir, Colorado can beat the world in eclipses as in everything else.”

While modern astronomers no longer require eclipses to study the heavens, this year’s event will still inspire an epic pilgrimage. An eclipse festival in Oregon expects 30,000 visitors, and some Jackson hotels have been booked for three years.

We live with our eyes cast downward, fixed upon hand-sized screens; this year’s American eclipse offers a chance to lift our gaze to a universe far grander and stranger than the circumscribed worlds we cradle in our palms. “These rare and unearthly events … suspend human affairs and draw people out of their quotidian existence,” Baron writes. We may comprehend our solar system vastly better than we did in 1878, but our capacity for awe remains, fortunately, undiminished.

This piece originally appeared in High Country News. 

American Eclipse: A Nation’s Epic Race to Catch the Shadow of the Moon and Win the Glory of the World

By David Baron

W.W. Norton and Company

352 pages, $27.95