Deep underground, some caves on Earth are hiding a glowing secret—one that could help scientists understand how life might survive in extreme places like Jupiter’s icy moon, Europa.
In caves like Wind Cave in South Dakota, scientists have found rocks and minerals that glow bright colors—like pink, blue, and green—when lit with black lights (UV lights).
These glowing patterns are caused by tiny traces of chemicals, or “fossilized chemistry,” left behind by water flowing through the cave thousands of years ago.
Joshua Sebree, an astrobiologist (a scientist who studies life in space) at the University of Northern Iowa, is leading a team to study these glowing caves.
The goal is to learn how life might exist in dark, cold, and extreme environments—both deep below Earth’s surface and possibly on other planets or moons.
As Sebree and his students explore caves across the U.S., they use UV lights and portable tools called spectrometers to study the glowing minerals without damaging the cave. These tools collect a kind of “fingerprint” of each glowing rock, showing what chemicals are inside.
Student Anna Van Der Weide is building a public map of these glowing fingerprints to help scientists understand more about the history and formation of these caves.
Other students are working on cool projects too: Jacqueline Heggen is studying how tiny life forms could survive in these extreme places, Jordan Holloway is building an automatic version of the spectrometer for future space missions, and Celia Langemo is studying how to keep explorers safe in harsh environments.
Working in caves isn’t easy. In Minnesota’s Mystery Cave, for example, the team had to wrap their batteries in hand warmers to keep them working in the cold. Sometimes they had to crawl through tight spaces only a foot wide or stand in freezing water to take their measurements.
But their hard work is paying off. In Wind Cave, they found that glowing zebra-striped rocks (called zebra calcite) were formed by manganese-rich water. These rocks helped shape the cave in a way that hasn’t been studied before.
Sebree hopes to keep using this non-destructive glowing technique to explore even more caves—and eventually apply what they’ve learned to other worlds.
“It’s amazing how much science you can do in the dark,” says one student.
Who knows? What we learn from glowing caves here on Earth may one day help us find life in space.
Source: KSR.
