Space travel CAN alter your DNA. That’s what NASA’s saying upon preliminary review of its Twins Study. As you’ll recall, astronaut Scott Kelly spent a year in space aboard the International Space Station and now that he’s back, about seven-percent of his genes have not returned to normal.
That means Kelly's DNA is no longer an exact match with his identical twin brother Mark, who remained grounded. The landmark study is designed to help researchers understand the possible changes the human body may undergo on a three-year mission to Mars.
Scientists say more research into how the human body adjusts to the stress of long-duration spaceflight as well as weightlessness, isolation, radiation is needed before astronauts can be sent on journeys that would triple the time humans have spent in space so far.