Microbes living in this Greenland island
produce hydrogen sulfide, and the sulfur
gives the snow its sunny hue.
Photos courtesy of Benoit Beauchamp
While conventional wisdom frowns upon getting too close to yellow snow, to a geologist such a feature can look like a pot of gold. On June 21, a team of researchers set out by helicopter and propeller plane to investigate a mysterious yellow snowbank on a remote Arctic glacier. The group, led by Benoit Beauchamp, director of the University of Calgary's Arctic Institute of North America, are examining strange, alien-like life forms living in the discolored snow and investigating the unique environment that sustains them. It's a far cry from E.T. and his flying bicycle, but the bacteria found in the snow might be the best model on earth for learning about extraterrestrial life.
The peculiar snowbank is located on Ellesmere Island, a huge landmass northwest of Greenland that is dominated by arching mountains and sprawling glaciers, and where the temperature averages around -5 degrees Fahrenheit for the year. Despite being the world's tenth largest island, it boasts fewer than 200 permanent residents—about one for every 450 square miles. The vast expanse of uninhabited land preserves natural wonders like the fossil from a transitional fish-on-land animal found earlier this year—and also Beauchamp's yellow snow.
Beauchamp discovered the snowbank about ten years ago while flying over in a helicopter while doing field work for the Geological Survey of Canada. When he first approached the spot by foot, it wasn't the strange color that struck him most. "I noticed the smell of rotten eggs," says Beauchamp, "and recognized it as sulfur." As he drew closer, he saw water bubbling up from yellow cones—piles of sulfur that accumulated on the glacier surface—and realized it was a sulfur spring. Beauchamp knew the phenomenon was unusual, especially on a glacier, but needed the help of a geochemist to understand it better.
Enter Steve Grasby, a geochemist with the GSC who visited the spring in 1999 and 2001. "It's just remarkable," says Grasby, who is accompanying Beauchamp on the current expedition. "You can smell the sulfur, you can see the yellow stains and the cones bubbling out water. It's the last thing you'd expect to find in a glacier."
Grasby tested the water and found 20 different strains of bacteria thriving in the sulfur spring. The hostile environment supported a diverse community of psychrophiles—organisms that flourish in extreme cold. With little easily accessible oxygen about, these bacteria extracted the vital element from sulfate minerals in the glacier through a chemical process called reduction. This produces hydrogen sulfide, known for its rotten-egg smell, which in turn can deposit bright yellow sulfur.
When Beauchamp and Grasby published their findings in 2003, NASA took interest. Planetary scientists noticed striking similarities between the frigid conditions of Ellesmere Island and those of Jupiter's ice-covered moon, Europa. The moon has an oxygen atmosphere and scientists suspect that sulfur is present, as well. Additionally, its ice surface is thought to float atop a subterranean ocean of water or some other viscous substance. The ice sheets rearrange themselves through what Beauchamp calls "ice tectonics," like plate tectonics on Earth. All things considered, scientists think Europa offers the best shot to find evidence of extraterrestrial life—and Beauchamp's sulfur spring offers the best terrestrial model of Europa.
While there are no formal plans for a NASA mission to Europa yet, it's a top priority for many researchers working for the organization, says planetary scientist Bob Pappalardo of NASA's Jet Propulsion Laboratory. According to Pappalardo, some members of Congress and influential groups—like the NASA Astrobiology Institute's Europa Focus Group and the National Research Council—support a mission to Europa, and are lobbying NASA for its implementation. Once approved and assembled, the spacecraft would zoom out to Europa, examine the surface, and relay information back to scientists, who would compare it to conditions for life on Earth.
Pappalardo has also introduced a proposal that would send planetary scientists to Beauchamp's spring to develop strategies and test equipment for a Europa mission. If his plan is approved, the site would provide planetary scientists with a working model of what to look for on the moon's surface. Although these bacteria live in one of the remotest places on earth, they could provide the key for finding our nearest neighbors in the universe.