There aren’t many unexplored places left on the planet, and most of those that remain are far beneath its surface. No one knows where the world’s deepest cave is, and vast expanses of the ocean floor remain unmapped. But if you want to explore the top of the world, one of the only places to go is, well, the top of the world. Few people have visited the central Arctic Ocean; even fewer have observed it during winter—its most fearsome season, and the world’s darkest.

Before long, though, scientists will have a chance to do just that. Later this decade, a new project—the Multidisciplinary Drifting Observatory for the Study of Arctic Climate, or mosaic—will set out to study the Arctic in unprecedented detail, across an entire year.

Mapbox; Katie Martin; Data: NASA, Natural Earth, NGA, NPI, NSIDC

The icebreaker Polarstern will leave Norway in the fall of 2019, cruising to a point north of the Siberian archipelago Severnaya Zemlya. From there, it will steer its way into the Arctic’s thin autumnal sea ice and—if all goes according to plan—get stuck. The Polarstern will remain trapped in sea ice for the next 12 months, carried along as the wind and ocean currents drive the ice through the central Arctic and, eventually, into the Greenland Sea. 1

Fridtjof Nansen

This will be an unconventional mode of transport—most ships in the Arctic are desperate to avoid getting stuck in ice—but the Polarstern won’t be the first to try it. In 1893, the Norwegian explorer Fridtjof Nansen ​2 deliberately engulfed his ship, the Fram, in ice, in the hope that it would carry him toward the North Pole. Though he never got there, he did travel farther north than any previous recorded voyage. More recently, in 2015, the Norwegian research vessel Lance spent five months conducting research while deliberately locked in ice. 3

Paul Dodd / Norwegian Polar Institute

The Polarstern will stay more than twice as long. Using the ship as their base, scientists hope to observe nearly every aspect of the Arctic system: the drifting ice, the turbulent ocean, the blustery atmosphere, and the organisms that make it home.

Pressing questions about that ecosystem remain. Right now, scientists suspect that the Arctic Ocean may be a carbon sink—that is, it appears to capture more greenhouse gas than it releases—thanks to its phytoplankton, which absorb carbon dioxide via photosynthesis. But no one knows how these small creatures survive the world’s longest night. Nor do scientists know whether life in the Arctic is limited mostly by darkness or by scarce nutrients.

They don’t understand how Arctic weather works, either: Does the wind cool off sea ice as it skips along the surface? Can eddies of water break up ice? Researchers hope that data gathered by mosaic will improve models of day-to-day Arctic weather. Those predictions are important not only for the industries and militaries looking to exploit the Arctic in the decades to come, but for everyone else, too. For one thing, recent research suggests that warm spells in the Arctic are linked to unusually unproductive years for American crops.

Clint Ford

The answers to these questions will in turn help scientists answer perhaps the largest question of all: Will the Arctic Ocean, as it warms, keep absorbing carbon—or will it one day begin to belch CO2 back into the atmosphere?

In search of answers, the Polarstern’s crew will set loose a constellation of sensors across all levels of the environment. Researchers plan to use weather balloons to monitor the atmosphere and planes outfitted with electromagnetic sensors to measure ice thickness. They will also leave behind a network of ice-tethered sensors and “snow buoys.” 4

For now, the hardest part of working in the Arctic is reaching it. “November, December, January, February—those are typically the no-access months for scientists,” says Benjamin Rabe, who is leading ocean research for the project. For much of the year, the standard way for researchers to access the central Arctic is to pay for a trip to Camp Barneo, a Russian-operated tourist camp that sets up annually somewhere near the North Pole. Freezing the Polarstern in place will circumvent this—although mosaic will still depend on nearby countries to help transport new scientists out to the craft every two months via helicopter, airplane, or another icebreaker.

Soon, access will be much easier. The extent of Arctic sea ice 1 this year is expected to be among the least ever recorded. And if carbon emissions continue at current rates, by about 2043—150 years after the Fram’s journey—summer sea ice in the Arctic will almost certainly be a thing of the past.