A new study conducted on mice has been investigating what the effect of radiation in space that astronauts would be subject to on a mission to Mars might do to the brain. NASA hopes to put astronauts on the surface of Mars or possibly asteroids closer to the earth in the coming decades. According to the study, researchers have shown for the first time that exposure to radiation levels equivalent to a Mars mission could produce cognitive problems and speed changes in the brain.
According to the researchers, the changes the radiation can cause in the brain are associated with Alzheimer's disease. The author of the study is Kerry O'Banion, a neuroscientist from the University of Rochester Medical Center. The problem with deep space missions is that astronauts are outside the Earth's protective magnetic field that shields us from harmful radiation.
Once astronauts venture out of lower orbit, they are constantly bombarded with dangerous cosmic rays. The longer the astronauts are in space, the greater the risk. This is concerning for NASA because it hopes to send astronauts to Mars by about 2035. The round-trip to and from Mars could take at least two years.
This study investigated a specific type of space radiation known as high-mass, high-charged particles or HZE. Shielding astronauts from these potentially hazardous particles is a very difficult job according to the study. These HZE particles have enough mass and speed to allow them to travel through solid objects such as spacecraft and astronauts inside. O'Banion says that to shield astronauts from these particles effectively the spacecraft would have to be wrapped in a 6-foot thick block of lead or concrete.
The researchers tested the mice using iron HZE particles generated by a particle accelerator at the NASA Space Radiation Laboratory. The mice were dosed with radiation levels comparable to what astronauts might receive during a Mars mission. After dosing the mice with radiation, the rodents were subjected to a series of experiments where they had to recognize places linked with electric shocks to their feet. The researchers found that rodents dosed with radiation were far more likely to fail the tests than those not dosed. Dosed mice also showed signs of inflamed blood vessels and abnormally high levels of beta amyloid, which is a protein that accumulates as one of the hallmarks of Alzheimer's disease.