On Aug. 21, the day of the “Great American Eclipse,” David Sliski, a graduate student in the Department of Physics & Astronomy in the School of Arts & Sciences, remembers getting goosebumps when the temperature dropped and the sky quickly darkened as the moon passed in front of the sun.
“The dogs were laying down and the birds were trying to figure out what’s going on,” he says. “It was a strange feeling.”
But his sense of awe was quickly put on hold as he scrambled to make sure that his telescopes and cameras were working properly to document the rare event.
Sliski had been talking with Jay Pasachoff, an astronomer at Williams College who has hunted solar eclipses for more than half a century, since 2005, when they did an undergraduate interview together. Although Sliski didn’t end up going to Williams College, the two kept in touch, talking back and forth about collaborating on something for more than a decade.
When Pasachoff invited Sliski to join him on a solar eclipse expedition to Oregon, Sliski jumped at the opportunity. Although some scientists who study eclipses are interested in better understanding the sun’s influence on Earth, Sliski hopes to use what he learns to assist in the hunt for other Earth-like planets outside of our solar system.
The event, Sliski says, was the culmination of weeks of preparation, writing scripts, mounting the telescopes, cameras, and conducting a dry run to make sure everything was in place to record this atypical occasion.
“With an event like a solar eclipse, there’s no going back, you don’t have second opportunities,” Sliski says. “The event in Salem, Ore., lasted for just one minute and 55 seconds and there’s no margin for error.”
Sliski uses Doppler shifts—the slight “wiggling” caused when a planet orbits and exerts a slight tug on its star—to try to discover exoplanets orbiting nearby stars. He hopes that the images he took of this eclipse will offer him the opportunity to better model other stars and figure out how they work by studying the closest star to Earth, the sun.
“The eclipse gives you information about the solar corona in between what the space-based observatories can measure and what ground-based observatories can measure,” he says. “By connecting these magnetic field lines, you can actually look at the differences between predictive models of the sun versus what you can actually measure. One can then put all of the data together to make a composite image and improve solar and stellar models.”
In addition to its usefulness for scientific exploration, Sliski believes the recent eclipse was a great way to show the public, particularly people who have trouble accepting the fact that the future can be predicted, that science really does work.
“I can create a model of a phenomena and I can observe the same phenomena, and then I can compare these things and see what’s real and what’s not,” he says. “That informs us about our future. It’s just exciting to see that process and to be involved in it.”
Once he confirmed that his telescopes were working and recording the eclipse, Sliski says the sense of awe returned.
“The curiosity inside kind of rushes to the surface,” he says, “and you think, ‘Well, if there's all this there, can I see more? What else is there?’”
Having dedicated so much time to understanding the math and science behind physics and astronomy, Sliski says the eclipse “unfolded an extra element of beauty in the moment of totality.” It allowed him to understand why the magnetic field lines were curved, how they connect, and why the shapes are the way they are.
“There’s a reason why the School of Arts & Sciences is combined,” he says. “This is where the beauty of nature exposes itself. When you look at that thing, which you’ve studied and made numerical models of and realize how beautiful it is, you have this moment where you realize all of the stuff you studied is real, and it’s not just made up in a laboratory or written on a chalkboard.”