As it floated across the central Arctic, scientists on board collected myriad data on the Arctic climate system—its clouds, atmosphere, ocean physics and biology, to name a few. This summer was marked by unusually high temperatures and low sea ice extent, particularly along the Russian coastline. In September, as the Polarstern was cruising home, Arctic sea ice cover hit its second-lowest extent in recorded history. The expedition also observed, firsthand, the thinning and melting of the Arctic sea ice. “You just need your eyes to see that the Arctic ice is dying,” Rex noted.