An Astronaut’s Genes No Longer Match His Twin’s — What’s to Blame, Space or Stress?
8 years ago Lily Garner
Astronaut Scott Kelly is remarkable for many reasons. He is a twin, has written multiple books, was commander of the International Space Station, and once had a serious Twitter bromance with Barack Obama. He also set the record for the longest consecutive time in space by an American astronaut, spending a total of 520 days in space with his longest run being a 340-day mission.
But Kelly's most remarkable feat was recently revealed to be a byproduct of his ultralong space runs: Kelly's DNA has changed so much that it no longer matches that of his identical twin, Mark Kelly.
NASA studied both twins as a part of its Twins Study to compare what happened when one twin spent an extended period of time in space while the other remained back on Earth. The findings, according to CNN, found that seven percent of Kelly's genes are no longer the same and no longer match his brother's. That seven percent mismatch — which scientists are now calling "space genes" — represents ch..