The melting Arctic icecap means a loss of habitat for many Northern animals, most famously, polar bears. Less famously, ice worms. These mysterious little creatures live on glaciers and thrive at the freezing point. That has NASA interested, because the worms may provide clues to how life could exist on colder planets. But they'll have to hurry and study them before the glaciers disappear.

On a recent rainy morning, Roman Dial tromps out to Byron Glacier south of Anchorage, on the hunt for ice worms. The Alaska Pacific University biology professor says there's not much chance of finding any, because the worms hide inside the glacier ice during the day. He explains that they don't drill their way to the surface until the sun sets. "When they all start bubbling up right about twilight, they look like little pinheads coming up to the snow, little black dots, then they squeeze up and emerge out of the snow and start crawling around."

But today he's in luck. Maybe because the sky is overcast, some 2.5 centimeter-long worms are still wriggling across the blue ice. Professor Dial chips away at the ice and puts chunks into an insulated jar. Then he carefully slides one worm after another into the jar, which he'll send to his fellow researcher, Dan Shain of Rutgers University.

Professor Dial examines a small worm, only about a centimeter long, before sliding it into the jar, and says there are lots of unsolved mysteries about these creatures. "This is definitely a young one. Nobody has seen any eggs yet of these guys or actually seen how they reproduce and I don't think anyone really knows how long they live," he says. "Like that little baby I just picked up, I don't think anybody's certain how old that might be, whether it's from this year or last year or ten years ago."

But scientists are beginning to unlock one of the biggest mysteries about ice worms - how they survive at such frigid temperatures. Professor Shain of Rutgers has discovered something unique about ice worm physiology that enables them to endure the cold better than humans. "If we jump into a cold lake, our energy levels are rapidly depleted and pretty soon we can't move and we die," he says. "If we were to throw them in a very cold pool of water, even well below zero, as they approach their freezing point, their energy levels go the other way. They just keep getting more and more energy, the colder they get."

That adaptation caught the attention of the U.S. space agency, which recently awarded Professor Shain more than $200,000 for worm research. NASA astrobiologist Michael New says there's an extra-terrestrial reason for their interest. Europa, one of the large moons of Jupiter, has what looks to be an ice-encrusted ocean, which could harbor life. "If we're interested in looking for life on ice-enshrouded worlds," he says, "then understanding how life on earth has evolved and adapted to living under those conditions is an important thing for NASA to know."

It's too complicated to send a probe to Europa, so the next best thing is earth-bound research in a similar environment. It's part of NASA's research into extremophiles - organisms that live in extreme conditions ranging from the boiling hot springs of Yellowstone National Park to hydrothermal vents at the bottom of the ocean. As the scientist points out, "We try to understand the distribution and extent of life on the earth in order to inform our ability to look for life elsewhere."

Biology professor Roman Dial of Alaska Pacific University Back at Byron Glacier, Roman Dial has just found a patch of snow where ice worms appear to be thriving. "Look at here's a little nest of them." He counts them. "Three, four, five, six of them right within an inch of each other." But their future is precarious. This patch of snow is no longer connected to the glacier and is rapidly melting. Professor Dial says Byron Glacier -- like much ice worm habitat -- has shrunk dramatically in just one year. A warming Arctic could be the ice worms' undoing.

"Potentially, somewhere," Roman Dial theorizes, "ice worms might be able to adapt to this sort of situation and live in the rocks and maybe evolve back to something that's not an ice worm. You know, it's possible, but I think this idea that these are worms that only live on ice means that once the ice is gone, the ice worms will be gone."

So this creature, adapted to live in a frozen world, must now adapt to the thaw. Or, like the polar bear, face possible extinction.