The Andes Mountain range runs along the edge of western South America. Microbial life has found a home high in those mountains, in ice spires called nieves penitentes (penitent ones) because they resemble praying monks. With elevations of 13,000 feet or more, this cold and arid environment is a harsh one, subjected to high winds, strong UV rays, and wild temperature fluctuations, and may parallel conditions on some other planets. Researchers from the University of Colorado Boulder have learned that microbes can find water in the penitentes, allowing them to survive in a dry place with few nutrients.
A team of scientists from CU Boulder went to the second highest volcano in the world, Volcán Llullaillaco in Chile, to learn about this environment along with Chilean colleagues.
"This is a very remote area that's difficult to access," noted the study co-author Steve Schmidt, a professor in CU Boulder's Department of Ecology and Evolutionary Biology (EBIO). "The entire back of one of our pickup trucks had to be filled with barrels of drinking water. It's no trivial thing to go out there, and that's one of the reasons these formations haven't been studied much."
The researchers went to penitente fields that are 16,000 feet above sea level and found red patches in the snow there. That indicated the presence of microbes. Red snow has been found around the world, and it's made by green algae called Chlamydomonas nivalis, which also carries a red pigment.
The team collected samples that they took back to the lab for analysis. That showed that algae were indeed present there; high in the mountains they had found both Chlamydomonas and Chloromonas algal species. Their work, reported in Arctic, Antarctic, and Alpine Research, is the first to show that there is life in the penitentes.
"Snow algae have been commonly found throughout the cryosphere on both ice and snow patches, but our finding demonstrated their presence for the first time at the extreme elevation of a hyper-arid site," said the lead study author Lara Vimercati, a doctoral researcher at EBIO. "Interestingly, most of the snow algae found at this site are closely related to other known snow algae from alpine and polar environments."
Researchers are always trying to learn more about how life survives in extreme environments, and how it is limited, which can help us learn more about the basic aspects of biology as well as extraterrestrial life. Formations that resemble the penitentes have been found on Pluto and are thought to exist on a moon of Jupiter, Europa. Chile's Atacama region, one of the driest places on Earth, is also thought to be an environment that analogous to Martian soils.
"We're generally interested in the adaptations of organisms to extreme environments," Schmidt said. "This could be a good place to look for upper limits of life."
"Our study shows how no matter how challenging the environmental conditions, life finds a way when there is [an] availability of liquid water," Vimercati said.
Learn more about red snow from the video above.