Tomorrow's edition of the journal Nature will include a paper documenting the existence of microorganisms living far beneath Antarctic ice. Special drilling and extraction techniques allowed scientists to tap into an active ecosystem half a mile below the surface of the West Antarctic Ice Sheet, where life was found in a lake untouched by sunlight or wind for millions of years. The discovery raises the obvious question of what other extreme environments might be able to harbor life on our planet, or beyond. 
 
 A team led by Montana State University professor John Priscu brought up samples from below the ice that contained single-celled microbes called Archaea, which convert ammonium and methane into energy to survive and grow. 
 
 “We were able to prove unequivocally to the world that Antarctica is not a dead continent,” Priscu said in a release. Similar expeditions have found sub-ice environments teeming with bacteria in recent years, but questions have been raised about possible contamination in the drilling process. The paper's lead author Brent Christner says with this latest effort, there is now clear proof. 
 
 “It’s the first definitive evidence that there’s not only life, but active ecosystems underneath the Antarctic ice sheet, something that we have been guessing about for decades. With this paper, we pound the table and say, ‘Yes, we were right.’” 
 
 The conditions below that Antarctic ice sheet have certain characteristics in common with known places on other worlds in our solar system, leading many to wonder if life might be more inevitable in those distant locales than previously thought. 
 
 Saturn's moon Titan , for example, is far colder than Earth, but plays host to vast lakes of liquid methane that could be a potential feast for hearty microbes similar to those living under the Antarctic ice sheet. Tidally-heated liquid oceans are also believed to exist beneath the icy shell of Jupiter's moon Europa and other objects in our solar system. 
 
 Some of the graduate students working on the mission to retrieve microscopic life from beneath Antarctica reportedly joked that they may have reached an early peak in their scientific careers. 
 
 “Some of the graduate students joke, ‘How do we top this?’ We can’t,” said Montana State doctoral student Alex Michaud. 
 
 Perhaps not. At least, not if they continue to limit their research to this planet. NASA could launch a mission to explore Europa sometime in the 2020s. ||||| New research suggests that lakes of liquid water could be buried in the icy crust of Europa, a moon of Jupiter. The processes that create the lakes could also provide nutrients crucial for life on Europa, the scientists say. 
 
 A file image from the Galileo spacecraft shows the Conemara region of Jupiter's frozen moon Europa. Scientists say the surface features suggest that a lake of liquid water once existed beneath the ice. 
 
 Mysterious depressions and domes on Jupiter's ice-encrusted moon Europa may signal the presence of subsurface lakes, at least one of which holds enough water to fill the American Great Lakes. 
 
 The finding, if confirmed, could be a boost for those who speculate that simple forms of life could exist on the moon. 
 
 For several decades, scientists have known that an ocean of liquid water exists beneath Europa's crust of ice. But some research suggests that Europa's ice shell could be miles thick. The subsurface lakes described by NASA scientists Wednesday, however, appear to exist within that icy mantle, meaning they would be at a far shallower depth than the underlying ocean. 
 
 Moreover, the lakes could be part of a planetary dumb-waiter system that transfers potential nutrients from the surface to the subsurface ocean, the team suggests. That transfer of nutrients could be crucial to any potential life on Europa. 
 
 With liquid water, Europa already has one necessary ingredient for life. That has made it "a compelling object for study for decades," says Tori Hoehler, an astrobiologist at NASA's Ames Research Center in Moffett Field, Calif., who was not part of the research team. 
 
 But another requirement for life, he adds, is a source of energy, a.k.a. food. The moon's upper crust is rich in compounds that could be a food source, but the potential nutrients would need a system to deliver them to the ocean deep below. 
 
 The mechanism that forms the subsurface lakes – involving rising plumes of heat – could provide that service, the team suggests. 
 
 If the team is right, "you've moved from a system that checks [off] one of the requirements for life to a system that checks two requirements for life," Dr. Hoehler says. 
 
 The results, set for publication in Thursday's issue of the journal Nature, grew out of an attempt to explain two different areas within Europa's "chaos terrain" – a landscape of jumbled surface features visible in images from the Voyager and Galileo spacecraft. 
 
 The two areas that have puzzled scientists cover significant large patches of the moon's surface and host icebergs with ground-up ices filling the channels in between – much as jumbled ice chunks fill gaps between icebergs as they calve from ice shelves in polar regions on Earth. 
 
 One of the two areas appeared as a depression in the surface. The other appeared as a dome. 
 
 "Why are these two features so similar but so different?" says Britney Schmidt, a planetary scientist at the University of Texas at Austin who led the research team. 
 
 In trying to solve the puzzle, the team was struck by parallels on Earth. Similar features are apparent in ice that forms above under-ice volcanoes, as well as at ice shelves where warm sea water is thought to be thinning the ice from underneath. 
 
 The team suggests that plumes of warmer water, heated by Europa's core, migrate up through the thick icy crust until they reach a "sweet spot" where a combination of pressure, temperature, and the composition of the ices allows a subsurface lake to form. Since liquid water takes up less volume than water ice, the icy lid on top of the lake begins to crack and collapse in a kind of frigid sink hole. The surface ice breaks into chunks in the process. As it does, some of it overturns, mixing the potential nutrients into the water below. 
 
 That explains the depressions. But what about the domes? 
 
 Over time, the lake refreezes and expands. This pushes remaining large ice blocks upward. The brine surrounding the blocks also refreezes, expanding as it does, adding to the dome. 
 
 One of the features, Thera Macula, is a depression, suggesting that a Great Lakes-scale body of water some two miles below currently is sculpting the surface, the team says. A dome feature, known as Conamara Chaos, represents the end of another lake's thaw-freeze process. 
 
 Over time, researchers have debated whether the icy shell covering Europa is thin or thick – thick roughly defined as more than six miles top to bottom. But neither camp can adequately explain how the chaos terrain forms, the team posits. 
 
 The team's new explanation "is a really interesting half-way point that is much more realistic," says Geoffrey Collins, a planetary scientist at Wheaton College in Norton, Mass. "It's not just 'only liquid down here and only ice up there.' There are perched lakes or slushy areas in the ice shell that may be having a huge effect on the surface geology," he says. 
 
 The thin-thick argument is of interest to astrobiologists, says Dr. Collins. If the crust is thick – say, 18 miles or so – that would leave little hope of ever being able to sample the ocean and check for signs of life. If it's thin, hope would spring eternal for sending a robotic mission to study what's beneath. 
 
 The new explanation leaves open the possibility for exploring potentially habitable environments even if the icy shell turns out to be a thick one. 
 
 Collins, however, is less convinced that the process can bring nutrients in the upper crust down to any hidden ocean. In the scenario the team lays out, the heat plumes that form the lakes – and the lakes themselves – don't come into contact with an ocean at any depth below the surface. 
 
 But Curt Niebur, NASA's program scientist for the outer planets, explains that it's possible the overturning ice can transfer any potential nutrients to the water or slush below. That leaves the enriched material free to migrate back down through cracks in the ice. 
 
 These ideas require missions to Europa to test them, researchers acknowledge. 
 
 Even so, "I'm really excited" about the team's proposed solution to the chaos terrain conundrum, Collins says. Thick shell or thin, if the presence of the lakes can be verified, they could be "interesting, accessible bodies of liquid water." ||||| Although it's often thought of as a vast space of nothing but ice, Jill Mikucki found Antarctica to be a place of overwhelming beauty. 
 
 Mikucki, an assistant professor of microbiology at the University of Tennessee, said she's led to research there by the many unanswered questions. 
 
 "Antarctica is still one of those places where you can still ask, ‘Is there life here?' " Mikucki said. 
 
 Although life on the frozen continent has long been studied, Mikucki was lead author for a research team that looked for life beneath the surface. Their research included time spent in Antarctica during 2011. 
 
 The continent's glaciers conceal a whole subsurface ecosystem. What Mikucki and the international team of researchers found shows the impact of ancient climate change and points to life that could survive extreme conditions, including on other planets. 
 
 The team found areas beneath the surface of the ice that can sustain life, and they believe microbes live in the newly found areas. 
 
 The team used an electromagnetic mapping sensor system called SkyTEM that was mounted to a helicopter and flew over several glaciers to find brines, or water saturated with salt, which formed waterways beneath glaciers. 
 
 The sensor was developed at the University of Aarhus in Denmark, one of the institutions with participating researchers in the study, and was used for the first time for the study. 
 
 Brine can also reflect previous climate change and have an imprint that's still left today, Mikucki said. She said what's below the surface could be entering the ocean, and that affects what's available in those waters, changing the ocean food webs. 
 
 One of the areas the team studied was the Taylor Glacier and a part of the glacier called Blood Falls, the water of which has a red coloring. 
 
 The coloring comes from iron in the water that surfaces and oxidizes like rust, Mikucki said. 
 
 Potential life in the brine at Blood Falls is a sign that life can survive in extreme conditions. Mikucki said those organisms would be capable of living in freezing temperatures, in salty liquid and in the dark beneath the glacier. 
 
 So knowing organisms can live in those conditions shows what types of organisms could be on such other planets as Mars, Mikucki said. 
 
 She said the research, a collaborative effort by scientists from various disciplines, sets the stage for more research to be done about where organisms live in Antarctica. 
 
 "Where next?" she said.
– A half a mile below the surface of the West Antarctic Ice Sheet, in a lake that hasn’t been touched by sunshine or wind in millions of years, life goes on. A large US expedition called WISSARD, led by a professor at Montana State University, has unearthed a thriving ecosystem of micro-organisms after drilling through the thick ice to reach Subglacial Lake Whillans in January of 2013, according to a university news release. Considered one of the planet's final frontiers, the subglacial environments below Antarctic ice sheets have long been suspected to harbor life of some kind. Many of the micro-organisms found are single-celled organisms, called Archaea, that survive by converting ammonium and methane into energy in a harsh environment similar to those found elsewhere in our solar system, such as on Jupiter’s moon Europa. That has led scientists to wonder whether primitive (but hearty) life thrives there as well, Forbes reports. "It's the first definitive evidence that there’s not only life, but active ecosystems underneath the Antarctic ice sheet, something that we have been guessing about for decades," the lead author says. "With this paper, we pound the table and say, 'Yes, we were right.'" The findings appear today in the journal Nature. (A group of European scientists is already prepping for a mission to search for life on Jupiter's icy moons.)