Researchers are now saying that a trip to Mars could be very unhealthy for any astronauts who are “lucky” enough to go. They say that the cosmic radiation pounding their brains during the trip could cause the onset of Alzheimer’s disease.
With appropriate warning, astronauts can be shielded from dangerous radiation associated with solar flares. But there are also other forms of cosmic radiation that, for all intents and purposes, cannot be effectively blocked.
Because this radiation exists in low levels, the longer an astronaut is in deep space, the greater the exposure. This is a concern for NASA as the agency is planning manned missions to a distant asteroid in 2021 and to Mars in 2035. The round trip to the red planet, in particular, could take as long as three years.