Lake Whillans, a small body of water huddled in eternal darkness beneath 800-metre-thick Antarctic ice, seems to harbour life.

Researchers with the US Antarctic expedition team WISSARD who accessed the lake on 28 January report that they have found microbes in samples of lake water and sediment — but what kind of known or novel organisms those might be has yet to be determined.

Alberto Behar, JPL/ASU

If the reported preliminary findings hold up, it is the first time that life has been discovered in a subglacial lake.

How the bacteria produce and metabolize energy in an environment probably deprived of oxygen and nutrients is unclear. Team members speculate that the organisms might live on energy extracted from minerals in surrounding rocks — a survival strategy also used by certain bacteria found in gold mines.

Antarctica’s hidden lakes, sealed for probably millions of years, mark one of the utmost frontiers for life on Earth. Many scientists think the lakes and what dwells in them will provide hints about which forms of life might exist on other planets or moons — for example on Jupiter’s moon Europa, which is thought to host a large sub-surface ocean.

Scientists recently found a wealth of bacteria in Lake Vida, another body of water in Antarctica’s McMurdo Dry Valleys. But Vida is not really a subglacial lake, and it has not been isolated from the outside world for nearly as long as Lake Whillans.

However, scientists have as yet found no traces of life in water samples Russian researchers took last year from vast Lake Vostok — the largest and best known of Antarctica’s roughly 300 subglacial lakes.

Having successfully finished their mission, the WISSARD researchers will now return to their labs in the United States and Europe, where the samples will undergo thorough DNA analysis over the next weeks and months.

“The data and samples collected have provided us with a glimpse of the Antarctic subglacial world,” the team wrote before they left their icy field site. “We have no doubts that our results will transform the way we view Antarctica and pave the way for future national and international subglacial research efforts.”