Researchers from the University of Northern Iowa are exploring some of the nation’s deepest caves to learn about life in extreme environments, and their findings could ultimately help NASA in its search for life on other planets.
UNI chemistry and biochemistry professor Joshua Sebree says he’s led undergraduate students on 50 to 60 fact-finding missions far underground, both in Iowa and several surrounding states.
“We go out to Coldwater Cave, which is the longest cave in Iowa at over 17 miles,” Sebree says, “and we visit there once a month for various research projects.”
While it would be difficult for people to live in those subterranean environments for long, Sebree says other creatures can thrive in caves, but they can be quite elusive.
“We’re always on the hunt for an extreme fish, the fish that can survive in caves, but then we’re also looking for different chemical fossils that have been preserved in the rock over time,” Sebree says. “We’re looking at how the glow-in-the-dark properties of these rocks can tell us about the different waters that made the caves eons ago and so we can get a picture of how the cave has evolved over time.”
The team of UNI cavers uses ultraviolet or “black” light to examine mineral formations in the caves, which will appear under ordinary light about like you’d expect, mostly shades of brown.
“It changes to another color. In some cases, it can be vibrant pink, it can be fluorescent green, it can be a soft blue,” Sebree says. “All of those different colors that come back out of those crystals are telling you about what are the parts of the crystal that have a little something extra beyond just the calcium carbonate.”
He says the glowing patterns can offer new insight into how water — and potential life — once interacted deep underground and could indicate how life might exist in places like Jupiter’s moon Europa. The caves, he says, can be absolutely stunning.
Sebree says, “You can enter some of these cavern spaces, flip on your black light, and you’re just surrounded by a technicolor whirlwind of all of these different bright crystals all around you.”
UNI’s research is being supported by NASA and the Iowa Space Grant Consortium.