Researchers said on Friday that long-term exposure to galactic cosmic rays, which permeate space, may cause dementia-like cognitive impairments in astronauts during any future round-trip Mars journey, expected to take at least 2½ years.
In a NASA-funded study, mice exposed to highly energetic charged particles like those in galactic cosmic rays experienced declines in cognition and changes in the structure and integrity of brain nerve cells and the synapses where nerve impulses are sent and received.
The irradiated particles in galactic cosmic rays, remnants of star explosions called supernovas, can penetrate spacecraft and astronauts' bodies. Earth itself is protected by its magnetosphere.