BBC: A highly unusual expedition is under way in the Arctic Ocean where a research vessel has been parked in the ice all winter.
Run by the Norwegian Polar Institute, the mission is exploring the big questions of how the region is changing and what this means for the ice and the wildlife.
This matters because the Arctic is on course to switch at some point this century from having permanent ice-cover to existing in a state where the ice comes and goes with the seasons.
That could open up everything...