Long-term galactic cosmic ray exposure leads to dementia-like cognitive impairments

What happens to an astronaut's brain during a mission to Mars? Nothing good. It's besieged by destructive particles that can forever impair cognition, according to a radiation oncology study. Exposure to highly energetic charged particles -- much like those found in the galactic cosmic rays that bombard astronauts during extended spaceflights -- cause significant damage to the central nervous system, resulting in cognitive impairments.