A third of us would go one-way to Mars – but it may shrink your brain | Artificial intelligence
Many people would consider going on a one-way mission to Mars, according to the 2018 New Scientist Asks the Public survey. But new evidence suggests that the lengthy trip may be bad for the part of your brain involved in forming memories.
The survey, carried out in August by Sapio Research on a representative sample of 2026 UK adults, found that 50 per cent of men and 30 per cent of women would be happy to go on a return trip to Mars. As for a one-way trip, 40 per cent of men said they would definitely or probably want to go, compared with 20 per cent of women.
This is despite the known physical risks that the six-month journey to Mars would involve. Aside from space-flight accidents, high exposure to radiation from cosmic rays could lead to DNA damage and cancer.
And there may be other unanticipated dangers. A NASA study presented at the recent Federation of European Neuroscience Societies conference in Berlin, Germany, suggests that a two-year mission with just a handful of crewmates could damage the brain.
The study involved 16 volunteers doing 30-day stints in a simulated Mars base with only three other people for company in their pod. By the end of the study, the participants showed slight shrinking of a brain area called the hippocampus, made up of sausage-shaped structures that are essential for forming new memories.
The study found that one end of the volunteers’ left hippocampus – known as the head end – shrank by about 3 per cent on average.
Team-member Anika Werner of Charité – Berlin University of Medicine suggests this shrinking may have been caused by social isolation and the stress of being watched 24 hours a day. The participants exercised six days a week, so the effect is unlikely to have been caused by inactivity.
What effect it might have on a person’s mental abilities is unclear. The hippocampus help us find our way around, but the navigation skills of the would-be astronauts were unaffected in computer tests during the study.
Hugo Spiers of University College London says the head end of the hippocampus may be less important for navigation and more involved in using memories to guide other kinds of behaviour. However, a longer study by the same team, looking at nine people who spent a winter at an Antarctic base, found hippocampus shrinkage that was linked to worse scores on spatial ability tests.
We don’t know how the volunteers’ hippocampus shrank. It might have been brain cells dying, a lack of new cells being generated, loss of connections between cells or just a reorganisation of this brain area.
Werner predicts, though, that any astronauts would recover after returning to Earth. “If you have these changes, they are very reversible. The brain is very plastic. But it is something that has to be taken into account.”
Many studies have attempted to assess the health effects of possible future Mars missions, including those conducted at the Mars Desert Research Station in Utah. Niamh Shaw, who took part in a simulated mission there in 2017, will be describing her experiences at New Scientist Live at ExCeL London on 23 September.
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