The challenge of taking people to Mars, which NASA and some private companies intend to relaunch as of 2030, is one of humanity’s most prodigious adventures, but it carries multiple risks , some of them unexpected until now for scientists.
According to a study carried out by researchers at the University of California Irvine (UCI), the effects of radiation from space particles during the journey on the human brain may be greater than previously thought. Already a study published in the journal Science in 2013 argued that the accumulated exposure for an astronaut only during the round trip, without counting the more or less prolonged stay on the Red Planet, would be equivalent to taking 33,000 X-rays . The new work from the UCI is even more alarmist and foresees that astronauts who go to Mars could suffer from chronic dementia, to the point that they may not even remember the trip when they return.
The research, published in Scientific Reports , describes the rodent analysis performed by radioactive oncology professor at the UCI School of Medicine Charles Limoli. According to their calculations, exposure to high-energy charged particles such as cosmic rays that bombard astronauts during prolonged space flights cause significant long-term brain damage and lead to cognitive impairment and dementia . For LImoli, the space environment poses specific dangers to humans. For example, exposure to these particles can lead to central nervous system complications during the journey and persist long afterward. These problems include poor performance, memory deficits, anxiety, depression, and difficulty making decisions. The worst thing is that these cognitive disorders can escalate throughout life.
The mice in the experiment were subjected to irradiation of charged particles of ionized oxygen and titanium. Six months after exposure, they still had significant levels of brain inflammation and neuron damage . The neural network of the brain was affected by the reduction of dendrites and spines of neurons, which interrupted the transmission of signals between brain cells. The consequence is that performance on behavioral tasks designed to test learning and memory deteriorated .
Additionally, radiation affected fear suppression, a process by which the brain removes unpleasant and stressful associations, making subjects more prone to anxiety. This type of cognitive dysfunction also occurs in patients with brain cancer who have received high doses of photons in radiotherapy treatments. The problem with a mission to Mars at this level is that it takes a long time, which would lead to the development of these cognitive disorders. This study raises the need to investigate and find solutions to mitigate the effects in future missions to Mars, such as more armor zones inside the spacecraft or preventive pharmacological treatments.
