With hard hats, sophisticated analytical equipment and sheer determination, University of Northern Iowa students under the direction of a professor in the Department of Chemistry and Biochemistry have been going deep below the Earth’s surface to discover insights into life in outer space.
Since 2019, Joshua Sebree and his students have made five separate research expeditions to Wind Cave National Park in South Dakota, the most recent being this past December. The trips have been funded in part by the UNI Foundation and, more recently, through a four-year, $350,000 grant from the Iowa Space Grant Consortium, a division of the National Aeronautics and Space Administration (NASA). The goal for Sebree and his students: collect and analyze samples of microscopic life and organic minerals found in the dark depths of the caves.
“We try to find field environments that model different areas in space,” Sebree, a professor of astrochemistry and astrobiology, explained. “The idea is by understanding how it is that life on Earth has evolved in these super extreme environments, that’s going to give us a better picture into what windows in the outer solar system we might be looking at for other types of extreme life.”
Sebree and his collaborators, which include faculty and students across seven academic departments, are a year and a half into the current NASA grant, which will continue to support cave trips through 2024. UNI students are one of just three groups in the world currently studying Wind Cave and are the only to do so at the undergraduate level. Their expeditions extend to rarely explored chambers of Wind Cave, which in some areas cut more than 400 feet below the surface.
The trips are exhilarating, Sebree says, not only for the science and the unique opportunities for his students, but also the physical triumph of pushing deeper into the cave with each visit and experiencing the strange, arresting stillness characteristic of being so far underground. Sebree described crossing What the Hell Lake, an underground body of water named for the astonishment cavers felt when they initially encountered it. As the story goes, up until the 1990s, What the Hell was an empty chamber — but a rising reservoir made the lake appear seemingly out of nowhere. It’s the penultimate stop before reaching Calcite Lake, one of the deepest portions of Wind Cave.
“You go through this eight-inch squeeze while you're balanced above What the Hell Lake — so you don’t want to fall in the water, but you’ve got to get through the hole that’s above the water,” Sebree said. “After crossing the lake, you go into a belly crawl. Then you finally get through the last couple squeezes in this big open amphitheater-type chamber, where you’ve got a giant rock in the middle and you’ve got Calcite Lake that pools around the rock making a peninsula. And it’s one of the larger chambers you get to visit in these deeper underground areas.
But it’s completely still, there are no ripples on the lake. There’s no wind blowing around. When you come into this chamber, there’s this quiet, eerie water down there. And it's just absolutely beautiful and absolutely silent. Your headlight can’t reach the back end of the chamber where you’re looking down at the lake because it’s just so far away.”
A demanding science
Wind Cave National Park is a sprawling 34,000 acres of forest and prairie located in the southwest corner of South Dakota. While bison and other wildlife roam the surface, Wind Cave, the first cave to be designated as a national park in 1903, is best known for its eponymous subterranean passages featuring honeycomb-like calcite formations known as boxwork. With 160 miles of surveyed caverns, it is the sixth-longest cave on Earth, according to the park’s website.
Yet much of it remains unexplored. Airflow studies suggest just 10% of the cave has been charted, and a still smaller fraction of the surveyed area has been scientifically studied. That’s partly because speleology — or caving, as it is more commonly known — is demanding work. One must overcome claustrophobia, the looming threat of a misstep and the challenges of crawling more than 100 yards on your belly or squeezing through tight crevices sometimes measuring less than a foot.
To prepare for the trip, Sebree asked UNI Department of Applied Engineering and Technical Management students to construct a “cave simulator,” a device comprised of adjustable wooden slats that allow would-be cavers to squeeze through simulated crevices they will encounter. It is just one example of cross-department collaboration that has stemmed from the Wind Cave expeditions, Sebree said.
The UNI Departments of Chemistry and Biochemistry, Biology, and Earth and Environmental Sciences have teamed up on the hard science for each of the trips, collecting and analyzing samples. And for the spring 2020 expedition, Sebree’s chemistry students were accompanied by a pair of digital media students who produced a series of short films documenting the experience. Original compositions from School of Music students score the films.
Megan Studer, a senior digital media student, has been working on the documentary shorts alongside her peers since the spring 2020 trip. Studer credits Wind Cave with inspiring a passion for filmmaking and journalism.
“It pushed me to a new level and revealed abilities I didn’t even know I had,” Studer said. “I can see myself pursuing something related to documentary filmmaking after graduation because of how comfortable I’ve become with it.”
In the documentaries, we see Sebree’s students light up as they discuss their work. For some, Wind Cave is their first research experience; for others, it’s a chance to apply the skills they’ve gained in the classroom to a new, unique environment.
Pratima Raut, ‘20, a biology and biochemistry graduate, attended two trips to Wind Cave while at UNI. Raut is currently enrolled in a biochemistry Ph.D. program at the University of Nebraska Medical Center where she’s working on pancreatic cancer research.
“These trips are the highlights of my UNI experience,” Raut said. “When I came to UNI, I thought I was not made for lab or research work ... but these trips, along with my other experiences from the department, helped me realize my passion for research.”
Emma Pellegrino, a junior biology and biochemistry major with future plans to enroll in a doctoral program, described Wind Cave as the experience of a lifetime. Initially reluctant to explore some of the deeper caverns, Pellegrino accompanied Sebree and another student on the most recent expedition last December.
“I had no idea what to expect, but it was just so beautiful,” she recalled. “I remember sitting down to catch my breath and waiting on a rock for other people to finish up their samples … and I was just like, ‘I can’t believe that I’m in this. I can’t believe I’m here doing this.’”
Cave study & analysis
The Wind Cave research amounts to a large array of tests: sampling mineral content and collecting organic material from water while performing analyses both in situ, or onsite, and later in UNI laboratories. Through the tests, they hope to learn more about how extreme life came to be in the cave and how it continues to grow and thrive.
The most visually striking analyses are the ultraviolet (UV) fluorescence measurements. For these tests, Sebree and his students shine UV lights of varying wavelengths onto rock formations to determine their mineral content. The corresponding fluorescence produces an impressive display of psychedelic colors amplified by the shadowy cave.
“Those colors indicate the different types of species that are trapped within the rocks: you can get a hot pink color, which would correspond to manganese; a bright green color, which might correspond to uranium; or a soft green color that could correspond to trapped organics. Or a lot of times you get a gentle blue, which are just air pockets that are trapped in the calcite,” Sebree explained. “But each one of those colors indicates what is trapped within the calcite. And that lets us get a picture of what’s in the rock … without actually harming these delicate cave features that have taken tens of thousands of years to create.”
Deeper study of Wind Cave has challenged Sebree and his team to innovate. Recognizing the need to travel light and protect expensive field equipment, they adapted the computing hardware from Lego Mindstorms kits — miniature robotic mechanisms designed for grade school Lego League competitions — to run standard water quality testing software.
“Nobody takes Legos in the cave but us,” Sebree laughs. “An interesting parallel is that [the Mindstorms kits] use Mars rover software to create Lego rovers, and I’m also using that same type of Mars rover analysis software to create the programs I need to get Lego to run my scientific instruments down underground.” The result means Sebree’s team is nimbler in the cave while using just a few hundred dollars’ worth of Lego equipment versus $40-50,000 in field equipment.
What the students uncover about microorganisms and geologic formations in the cave will eventually be released for publication, with students receiving co-authorships alongside faculty. For now, the public can enjoy an exhibition of their work on display at the Wind Cave visitors center and the UNI Museum.
Looking ahead to future expeditions, Sebree is excited to see more students “get bit by the field research bug.”
“I’ve watched [them realize]: ‘The science here is so cool. I don't care if I’m claustrophobic, I’m going to go.’ And they completely switch gears just by having a little bit of an introduction. Being able to see that tells me that I’m doing right by my students,” Sebree said. “And for myself, I get to study things that are fascinating. I get to go places where few people have gone to try to see things in ways that nobody has seen before. And I get to share that experience with people who would never get to do that ever in their lifetime,” he added.
“These trips are the highlights of my UNI experience. When I came to UNI, I thought I was not made for lab or research work ... but these trips, along with my other experiences from the department, helped me realize my passion for research.”
- Pratima Raut
Sebree has been going the extra mile — literally — to provide his students the research experience of a lifetime.
Following the 2020 spring break trip to Wind Cave, as the lockdown in response to the COVID pandemic meant students, faculty and staff at UNI wouldn’t be returning to campus, Sebree began a fitness journey that would enable him to take his students to new depths of scientific discovery.
The journey didn’t begin with that goal in mind — Sebree, like so many during the summer of 2020, took to exercising to relieve the stress of isolation.
“When things started shutting down on the social aspect — you can’t go into the office, you need to stay away from people — for my own mental sanity, I got back into bike riding. I hadn’t had a lot of spare time to ride my bike for years,” Sebree recalled.
Casual bike rides turned into longer, early morning jaunts pulling his two-year-old son behind him in a bike buggy. Midway through the summer, Sebree and his grant partners received word that their Wind Cave proposal was funded by NASA. That meant they’d be taking students to the Lake District of Wind Cave, far deeper than they had gone on previous trips.
“And I’m not going to send students anywhere I can’t go,” Sebree determined. Previous trips had shown Sebree that if he and the group were to reach Lake District safely, he had to get in shape. Over the next nine months, he covered 10,000 miles of cross-training between biking, running, hiking and kayaking.
“That knocked off 40 pounds of weight, and it took the diameter of my belly down from an 11-inch squeeze gap to an eight-inch squeeze gap,” Sebree said.
Sebree even brought his bike on the May Wind Cave trip following lockdown, racking up hundreds of miles cycling in the evenings the same week he and his students belly crawled for dozens of hours, navigating awkward cave squeezes to reach the Lake District.
And he hasn’t let up since.
“I’m now at the point where since that first cave adventure in 2020, I've gone 25,000 miles in terms of cross training distance between the biking, the hiking, the kayaking and everything else,” Sebree said. “So I’ve done the equivalent of a cross-training trip around the circumference of the Earth in preparation for going deeper into this cave.”
Sebree’s impressive health journey caught the attention of iRun, a Canadian publication that featured him on the cover of their March 2021 issue. In the article, Sebree had some advice for others looking to get active: pace yourself, set realistic goals and have fun.
“I’m not trying to push myself to be the next super-athlete,” Sebree told iRun. “I’m just trying to push myself to stay healthy — that’s my mindset. I don’t have to compare myself to others, I just want to be active and live a good life.” UNI
Joshua Sebree and his son at the largest frying pan in the world