A BBC nature documentary has inspired the search for life deep beneath Antarctica’s glaciers. Although no living things have yet been found, DNA of them has, increasing the possibility that life has found a way.
Dr Ceridwen Fraser of the Australian National University watched a “frozen planet” documentary featuring the ice caves of Mount Erebus. Along with other Antarctic volcanoes, Erebus releases steam that hollows out enormous interlocking cave systems deep under the ice.
“It can be really warm inside the caves – up to 25ºC (77ºF) in some caves,” Fraser said in a statement. “You could wear a t-shirt in there and be pretty comfortable. There’s light near the cave mouths, and light filters deeper into some caves where the overlying ice is thin.”
When she saw this, Fraser told IFLScience, she thought these “looked like the sort of places life might like.” However, being hard to reach and harder to explore, the caves haven’t had many visitors, most of whom have been geologists. Although large areas of moss would probably have been noticed, Fraser pointed out that “living things in Antarctica tend to be small, and easy to miss if you’re not a biologist.”
Fraser has been trying to establish whether volcanoes enabled life to survive ice ages in Antarctica, and saw an opportunity to explore their role today. She discovered that some biologists specializing in bacteria and fungi had organized for samples of regolith from the cave floors to be brought back for analysis. When she looked more broadly, most of the DNA she found came from plants or animals.
This doesn't mean the caves currently host life, Fraser stressed in Polar Biology. Her discoveries could be legacies from long-gone ecosystems or dead material that blew in from elsewhere.
Nevertheless, co-author Professor Laurie Connell of the University of Maine said: “The next steps will be to take a closer look at the caves and search for living organisms. If they exist, it opens the door to an exciting new world.”
The ice caves’ sizes are unknown, but it is thought that vast networks of interlocking chambers exist in several locations. Moreover, Fraser told IFLScience that the magma chambers of some Antarctic volcanoes are so large, they stay hot for hundreds of thousands of years. This means the caves may last long enough for complex ecosystems to evolve, even at the, shall we say glacial, pace at which Antarctic life tends to move. The interconnections could also enable lifeforms to move from one cave to another, outlasting any specific location.
Besides shedding light on Fraser's work on survival during ice ages, anything we learn may have implications for life in colder parts of the Solar System.
