How Snowflakes Created Life in a Subglacial Lake

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Alien Life—On Our Own Planet

Scientists have discovered life in a subglacial lake long thought too barren to sustain as much as a microbe. What does that mean for the possibility of life on other planets?

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Tulaczyk and others still don't know which theory best explains the microbes found in these subglacial lakes, but he and others are tantalized by the prospect that their presence indicates even more complex life forms could be dwelling in the deep.

“This may sound far-fetched at the first glance, but without further studies I wouldn’t rule out worms or sponges living down there or other life forms that tend to be more resilient in terms of survival,” Tulaczyk says. “And of course, any more complex life forms are likely to be an entirely new species, given the length of isolation from the rest of the genetic pool.”

Given the utterly inhospitable conditions of subglacial lakes, that may sound like a long shot. But an experiment at Lake Vostock has provided optimism. Recently, scientists studied the composition of refrozen lake water sampled at the bottom of an ice core, finding compounds extremely similar to those associated with fish-filled waters. Tulaczyk doubts that fish are swimming beneath the ice in Lake Whillans, but the mere possibility is too enticing to ignore.

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The idea that life can survive, and even thrive, in such a desolate environment doesn’t only resonate with Earth-bound explorers.

In the last few decades, NASA probes have discovered a giant ocean beneath miles of ice on Europa, one of Jupiter’s moons. (A future probe may specifically search for life beneath the ice.) Other ice-covered moons are known to orbit Jupiter and Saturn, leaving researchers pondering the possibility of life throughout our solar system.

The discovery at Lake Whillans makes this prospect all the more tantalizing; after all, according to Tulaczyk, the Antarctic subglacial environment resembles another planet more than it does Earth.

Yet glaciologists like Tulaczyk are once again racing against the clock in their efforts to study subglacial lakes. This time it isn't the approach of winter that is the problem—it's long-term climate change, and the prospect that these fast frozen reserves will disappear.

Already, the alarming increase in global temperatures is causing some parts of the Antarctic ice sheet to lose three to 30 feet a year. The problem is exacerbated by warming of Earth's oceans, which is accelerating the rate at which ice sheets are melting.

While glacial contact with warm air produces moderate melting, glacial contact with warm ocean water creates a faster melting rate—up to 10 times faster, meaning tens to hundreds of feet of melted ice per year.

And our oceans are heating up fast. Glacial ice near the coast of Antarctica is disappearing at unprecedented rates due to its constant contact with warming ocean water. And things may get much worse soon: Tulaczyk notes that many glaciologists point to a possible exponential increase in ice sheet retreat once climate change reaches a tipping point.