Astronaut's DNA no longer the same as twin brother after space mission

Looks can be deceiving for astronaut identical twins Mark and Scott Kelly.NASA has learned that Scott Kelly and his identical twin Mark Kelly are no longer genetically the same. Mark left, and Scott Kelly, right (NASA)Media Folder: Media Root
Scott spent a year on the International Space Station and NASA studied the brothers to learn how space impacts the human body. Preliminary results revealed that 7 percent of Scott's genes did not return to normal after his return to Earth.Researchers b