Four kilometers under the ice

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When you fly over Antarctica, you see nothing. No birds, no plants, just white. A continent that seems dead. And that's exactly the lie.

In 1970, a Soviet research team started drilling in the middle of this empty expanse. They wanted to know what lay beneath the ice. They drilled for a year. They drilled for ten years. They drilled for twenty-eight years, almost four thousand meters deep, and then they stopped abruptly. Not because they had reached the end. But because something suddenly appeared under their drill that shouldn't have existed: liquid water. A lake roughly the size of Lake Ontario, cut off from the rest of the world for fifteen million years. Lake Vostok.

How is that even possible? Two things keep the water liquid. First, the ice acts as a gigantic thermal blanket, trapping the warmth from inside the Earth. Second, the pressure down there is about 350 times the pressure at sea level, and under that kind of pressure, water stays liquid even below zero degrees. Physics. No magic.

But Vostok isn't the only one. When scientists went looking for more of these lakes — with radar from airplanes, with lasers from satellites — they found hundreds. A whole world under the ice. A mountain range that can hold its own against the Alps. A trench deeper than the Grand Canyon. A crater from an impact nobody knew about. And between the lakes: rivers. A complete water system that lifts and lowers entire sections of the ice sheet by up to ten meters, depending on where the water happens to be flowing.

And then came the real question. If there's water down there, and has been for fifteen million years — is anything alive in it?

The Russians tried first. They melted their way through the last layer with a heated drill and broke into Vostok in 2012. The lake water shot 363 metres up the borehole and pushed the drilling fluid — mostly kerosene — to the top. They let the sample freeze, hauled it up, and found a new species of bacteria. Except those bacteria looked suspiciously similar to the bacteria that lived in the kerosene to begin with. The international community remained skeptical — the sample was too obviously contaminated to count as evidence of Vostok life.

The British tried in 2012 at Lake Ellsworth, with a cleaner method: hot, UV-treated water instead of kerosene. They didn't make it through. Ran out of fuel.

The Americans broke through in 2013 at Lake Whillans. And in the sample they pulled up, there was something. Not just something. A whole lot of something. A complete ecosystem of bacterial colonies and microorganisms that functions without sunlight, without plants, without a classical food chain. In 2018 they did it again, this time with sediment samples. The analyses are still running. Early results point to life forms that don't exist anywhere else on Earth. Among them new viruses that only infect bacteria.

What's interesting about this discovery isn't the shock that there's life down there. Microbiologists have long assumed that bacteria are everywhere. What's interesting is what the existence of this life tells us about life itself.

First: what we call "hostile to life" usually just means "hostile to us." The habitable zone of a planet — the narrow strip in which life is supposed to be possible — is apparently much wider than we long thought. If bacteria don't just survive under four kilometers of ice at minus a lot of degrees and 350 times the pressure, but actually form thriving colonies, then that shifts the question. It's no longer about where life can be. It's about where it can't.

Second: these organisms were cut off from the rest of the biosphere for fifteen million years. That's a gigantic stretch of evolutionary time, running under completely different conditions from the rest of the world. If genuinely new gene structures, new metabolic pathways, new virus families really do turn up down there, then that's, to put it bluntly, a second experiment in evolution. Running in parallel to everything we know. On the same planet.

Third, and this is the real kicker: Antarctica wasn't always ice. Fifty million years ago it was a forest. What lives under the ice could therefore be older life that simply held on down there while the world around it froze. "Old new life," as one of the researchers calls it. Old life that seems new to us. That could open a window into earlier stages of evolution that we otherwise barely have any way to reach.

And the very same technique that was needed to drill cleanly into the Antarctic lakes without contaminating them is the technique we'll need to drill into Europa or Enceladus — the ice moons of Jupiter and Saturn, beneath whose icy crusts oceans are also suspected. Whoever cracks Vostok is rehearsing for the search for extraterrestrial life.

Hundreds of these Antarctic lakes are still untouched. What's waiting down there, we don't know. But that there's something down there, we know now.

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