The Martian atmosphere is extremely harsh and seemingly incompatible with human life. With Terrae Novae Strategy 2030+ and NASA's Artemis missions, a crewed Mars mission is aimed for the late 2030s. This poses unique physiological challenges, including cosmic radiation, altered gravity, and hypoxia. This presentation will discuss these challenges' impact on the astronaut's brain and highlight the Life Sciences Working Group's work for the European Space Agency.