Astronauts will face many hazards on a journey to Mars, including chronic exposure to radiation that could harm their minds and their bodies, according to a recent study published in the journal ENeuro.
But NASA's chief health and medical officer cautioned against undue alarm from the study as it exposed mice to higher levels of radiation than astronauts would likely experience in space.
"With dosages that we are expecting with a Mars mission, I'm not expecting to have a massive amount of cognitive decline in astronauts," J.D. Polk told NBC News. "Is there a high risk that they're going to come back with horrible cognitive decline and forget how to push the red button for re-entry? No."
Researchers exposed 40 mice to radiation for six months to simulate the radiation astronauts would be subjected to on a mission to Mars.
They then tested the animals' social interactions, conditioned fear responses, anxiety and depression, and memory.
The radiation-exposed mice "froze" in situations that caused no anxiety in the controlled animals.
"The nature of the radiation environment in space will not deter our efforts to travel to Mars, but it may be the single biggest obstacle humankind must resolve to travel beyond the Earth's orbit," researchers from Stanford, Colorado State University, Eastern Virginia Medical School and University of California, Irvine, wrote in the conclusion to their study, which was published Aug. 5.
The research suggests at least one of five astronauts sent to Mars would return with "severe deficits" in cognitive function.
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