Mission accomplished! On 13 October, the German research vessel Polarstern returned to its home port in Bremerhaven, ending a year-long international Arctic science expedition. MOSAiC (Multidisciplinary Drifting Observatory for the Study of Arctic Climate), which Polarstern is part of, is one of the biggest research missions ever to go to the Arctic. Last October, the ice-breaker travelled to the Central Arctic Ocean and allowed itself to become trapped in the ice. A rotating cast of scientists and technicians took samples of the ice, atmosphere and ocean, to study the effects of climate change on the Arctic region. In August, shrinking ice allowed the expedition to reach the North Pole. Here, the team gather to release the last radiosonde balloon, which measures variables such as pressure, temperature and humidity in the atmosphere.