SCOTT KELLY: NASA TWINS STUDY CONFIRMS ASTRONAUT'S DNA ACTUALLY CHANGED IN SPACE

Astronaut Scott Kelly’s DNA was altered by a year in space, results from NASA’s Twins Study have confirmed. Seven percent of his genes did not return to normal after he landed, researchers found.

Scott Kelly and his twin brother, Mark Kelly—also an astronaut—were the subjects of the study that sought to find out exactly what happens to the body after a year in space.

Scott stayed on the International Space Station from March 2015 to March 2016, while Mark remained on Earth. This was the final mission for Scott, who spent a total of 520 days in space during his career.