Peijnenburg is sailing on RRS James Cook ship. It is a British expedition with 20-30 British scientists, but Katja is one of the few non-Britons who has been allowed to join the trip. The ship is heading to Antarctica and Katja has been allowed to accompany the other scientists for a large part of the trip in order to conduct her research. The expedition will last from 10 October to 24 November for Peijnenburg. She boarded in Southampton and will leave the ship in Punta Arenas (Chile).

Peijnenburg, together with an American colleague, will focus on collecting marine zooplankton for ecological/evolutionary research. One of the questions they want to answer is whether marine zooplankton can adapt to a changing ocean ( as a result of global warming and acidification). They are going to do this by studying biodiversity at different levels (between and within species), as well as the population genetic structure of a number of 'target' species. Peijnenburg will focus primarily on the collection of arrow worms (chaetognaten) and slugs (pteropoden), and her  US counterpart will concentrate on copepods (copepods).

During her trip Peijnenburg is keeping a blog for children (in Dutch).