It sounds like a morph that could only surface in a sci-fi movie. But the notion that extensive missions in space can alter your body is turning out to have some scientific backing.
Those are the findings from NASA, which reported on Thursday that an examination of American astronaut Scott Kelly's genetic samples has indicated seven percent of his DNA remains abnormal after spending a year on the International Space Station. Researchers not only checked out samples taken before his flight and after his return to earth in 2016, they also compared the results with DNA taken from his twin brother Mark, who stayed behind.
It's been well documented that human bodies adjust to extensive periods in space. A weightless atmosphere can cause bones to get brittle and muscles to atrophy. But the study revealed that after months in space, Scott's body composition changed dramatically. His telomeres, parts of the chromosome that control aging, grew considerably during his mission and started to shrink within a couple days after he landed back on earth. Although the twins are 54 years old, the alteration of Scott's telomoeres during the mission actually made him biologically younger than his brother.
Scott's cells also showed a decrease in tissue-oxygenating hypoxia, after working on a station that had relatively higher carbon dioxide levels than what Mark was exposed to on earth.
Scientists found damage in Scott's DNA and RNA, likely due to extensive exposure to space radiation. Lab tests revealed a spike in amounts of — and damage to — mitochondria, a component that provides to the very cell it inhabits, suggesting high levels of stress inherent in working in a space environment. Also discovered were changes in bone formation and blood clotting due to extensive weightlessness.
The study of the twins is part of continuing research to determine the effects of interplanetary travel on the human body. A Mars mission, for example would take three years, triple the time Scott spent on board the ISS.