This summer, assorted faculty members and 16 alumni of the College will join Professor Jay Pasachoff and his research students in Oregon to view a total solar eclipse.
“We’ll be spending the first two months of the summer [on campus] learning about the sun and the equipment we’re going to be using,” Pasachoff said. The preparation will culminate in a trip to Oregon where, on Aug. 21, the moon will pass directly in front of the Sun, completely blocking, or “occulting” the sunlight.
“During the two minutes of totality, we get to see the structure of the everyday halo of the sun that is normally hidden behind the blue sky,” Pasachoff explained. He and his research team will be studying the sun’s inner corona with spectrographs. “It was discovered some decades ago that there are certain emissions at specific colors that come from iron atoms that are so hot they’ve lost about half of their electrons.” For that to happen, the atoms must be heated to at least 1,000,000 degrees Celsius. The eclipse thus offers a unique opportunity for researchers to measure the temperature of the sun’s corona. “No spacecraft can study this part of the sun,” he said.
Pasachoff hopes the eclipse viewing will inspire others to pursue astronomy as it did for him. His appreciation for the phenomenon developed when he was a first-year student at Harvard. “There happened to be an eclipse that was visible from an airplane in Marble Head, Mass. just two weeks after school began. My professor took 11 of us up in a borrowed airplane and the view of the eclipse was wonderful,” he recalled. “The others and I were hooked.”
Pasachoff has been chasing solar eclipses ever since. His field work has taken him all over the world, from neighboring Canada and Mexico to more far-flung countries like Chile, Iceland and Spain, to name just a few. “I have colleagues from all over the world,” Pasachoff reflected. Of the 65 expeditions he has made, over half have been to view total eclipses — but these were all outside of the United States. He has ventured to Hawaii, California and Washington, but these have all been for annular and partial eclipses. “There’s a total eclipse somewhere in the world about every 18 months,” Pasachoff explained, “but rarely in the United States.”
The eclipse this year will be the first total eclipse to cross the U.S. in 99 years, and is expected to draw both domestic and foreign spectators. Throughout the course of his career, Pasachoff has received so much hospitality from people in different countries and was adamant that “it’s our turn to welcome them here.” In addition to his artistic and educational preparations for the events, he is also been hard at work making sure the entire scientific community can witness the event. “I’ve been writing letters for some of my colleagues to get their American visas,” he said, “to people in China, in Japan and in Bulgaria.”
The invitation extends to U.S. residents as well. “I’m working with a task force from the American Astronomical Society to persuade 300,000 Americans to travel to that path,” Pasachoff said. Students are encouraged to participate, too, of course. “We don’t want Williams students to miss this one.”
While Oregon might seem like a long way to travel, Pasachoff emphasized the rarity of this opportunity to see a solar eclipse so close our doorsteps. The path of totality is only 70 miles wide, but it stretches over 3,000 miles from Oregon to South Carolina. “For [people in the path of totality], it’s a matter of just going outside to see it,” Pasachoff said.
Those who don’t live in this narrow corridor can get a map of the affected areas on websites like totalsolareclipse.org, or eclipses.info, a website which Pasachoff himself helped to coordinate with the International Astronomical Union. But for the best view, those able to travel should visit Oregon with the researchers. “Twenty years of satellite images have shown the western part of the track to be clearer than the eastern track,” he said.
I asked Pasachoff about what advice he would give to first-time viewers. “Don’t spend all the time looking at [your] camera’s viewfinder,” he recommended. Though it may be tempting to record the moment, Pasachoff spoke so rapturously of the event that it’s hard to imagine a Snapchat video could do the eclipse justice. So, if the tail-end of your summer is free and you can make it into the slim path of totality, heed the expert’s advice: “Just enjoy it.”