Skaters

A True Story of Discovery Beneath Arctic Ice

The research vessel Sikuliaq cut through the gray waters of the Chukchi Sea, a speck of human ambition in an ocean of white. It was the summer of 2023, and Qing Zhang stood on the deck watching polar bears traverse the distant ice—apex predators in a kingdom that might not exist in thirty years.

She had come to collect dirt.

Or rather, what looked like dirt. Those faint brown streaks running through the ice cores her team would soon extract. For decades, scientists had pulled these cores from the Arctic, noticed the discoloration, identified the organisms responsible—diatoms, single-celled algae encased in glass-like shells—and moved on. They were frozen. Dormant. Uninteresting.

Zhang suspected otherwise.

The Expedition

For forty-five days, the Sikuliaq hopscotched between twelve research stations across the Arctic. Each stop meant drilling into the ice cap's outer edges, extracting cylinders of frozen history. Zhang's advisor, Manu Prakash—a Stanford bioengineer known for inventing tools that made the invisible visible—had spent years developing microscopes that could peer inside ice without destroying it.

On the ship, surrounded by specialized equipment and the constant hum of generators, the team began their observations. What they saw defied expectation.

The diatoms weren't dormant. They were moving.

"You can see them actually gliding," Zhang would later recall, her voice still carrying a trace of that initial wonder. "Like they are skating on the ice."

Skating. At fifteen degrees below zero Celsius. In conditions that should have rendered any complex cell completely immobile.

The Laboratory

Back at Stanford, the real work began. Zhang and her team faced a delicate challenge: recreate the Arctic in a petri dish. They needed to understand not just that the diatoms moved, but how.

Arctic ice possesses a unique architecture. As seawater freezes, it expels salt, creating freshwater ice riddled with microscopic channels—highways barely wider than a strand of hair. The team needed to replicate this exactly.

The Ingenious Solution: The team used their own hair to create channels in laboratory ice, then lowered the temperature on their custom sub-zero microscope. They added a thin layer of frozen freshwater over very cold saltwater, mimicking the natural environment.

And they waited.

The diatoms slipped through the hair-thin channels like Olympic speed skaters, gliding with a grace that seemed impossible.

The Mystery Mechanism

What Zhang discovered next challenged everything biologists thought they knew about the lower limits of life.

The diatoms moved using a mechanism both ancient and elegant. They secreted a polymer—a mucus similar to what snails produce—that acted like a rope with an anchor. The diatom would lay down this "rope," grip it, and pull itself forward using molecular motors made of actin and myosin.

The same proteins that power human muscles.

Surprising because in that frozen environment, water molecules barely move. Chemical reactions slow to a crawl. Every biological process known to science suggests that complex cellular machinery—especially the delicate molecular motors that enable movement—should simply cease functioning.

Yet somehow, these microscopic algae had evolved a workaround. Their actin-myosin system operated in conditions that should render it inert. How remained one of the deepest mysteries the team now pursued.

The Green Beneath the White

During the expedition, the team deployed drones beneath the ice. The footage revealed something startling.

"The Arctic is white on top," Prakash explained, "but underneath, it's green—absolute pitch green because of the presence of algae."

Miles upon miles of it. These weren't isolated pockets of survival but vast communities carpeting the underside of the polar ice cap. And if Zhang's findings held true across all those square miles, then every one of those diatoms was actively moving, actively living, even in the depths of Arctic winter.

The implications cascaded outward like cracks in ice.

The Food Web Connection: Diatoms form the base of the Arctic food web. If they're this active, they might be redistributing nutrients in ways no one had modeled—creating highways of organic matter that feed zooplankton, which feed fish, which feed seals, which feed polar bears.

The Race Against Time

When Zhang compared her Arctic diatoms to their temperate cousins—related species from warmer waters—she found something else remarkable. The Arctic species moved faster. Significantly faster.

This suggested powerful evolutionary pressures had honed these organisms into specialists. They had adapted not just to survive the cold but to thrive in it, developing superior propulsion systems that gave them an advantage in an environment where every calorie of energy mattered.

But all adaptations are context-dependent. And the context was changing.

"Many of my colleagues are telling me, in the next twenty-five to thirty years, there will be no Arctic."

No ice meant no ice channels. No specialized habitat. No evolutionary advantage to being the fastest skater at the end of the world.

The organisms that had just redefined the lower temperature limit for eukaryotic cell movement—that had demonstrated biological mechanisms unknown to science—might disappear before anyone fully understood them.

The Record

On September 9, 2025, Zhang, Prakash, and their colleagues published their findings in the Proceedings of the National Academy of Sciences. The paper documented the mechanism—the mucus ropes, the molecular motors, the speeds that exceeded temperate relatives.

The Record: Minus fifteen degrees Celsius. Five degrees Fahrenheit. The coldest temperature ever recorded for movement by a complex cell.

But underlying every figure and finding was a simpler truth: in the most extreme environment on Earth, life had found not just a way to persist, but to flourish. To move with purpose and speed. To engineer solutions to problems that seemed insurmountable.

The diatoms were still skating in their frozen world. Still pulling themselves forward on ropes of mucus. Still operating biological machinery that shouldn't work at temperatures where water turns to glass.

How long they'd continue doing so remained the question no microscope could answer.

Based on research by Qing Zhang, Hope T. Leng, Hongquan Li, Kevin R. Arrigo, and Manu Prakash, published in PNAS, September 2025.