Scott Kelly Is Still His Brother’s Identical Twin Even After A Year In Space, NASA Says

NASA, had to clarify its initial reports when it said that astronaut, Scott Kelly’s DNA, had changed after spending a year in space aboard the International Space Station. Now, the space agency says that Kelly’s gene expression had changed and it’s very minimal at that.

Scott Kelly had spent 340 days aboard the ISS, returned to Earth in March 2016 and retired from NASA later that year. It was previously reported that Kelly’s DNA had changed during his time in space, something which was studied by the agency as part of its Twins Study. While Scott Kelly was in space, his twin brother, Mark Kelly, who is also an astronaut, remained on Earth. The brothers provided blood, saliva, and urine samples, underwent bone scans and ultrasounds, among other medical tests, as to pinpoint the exact changes in Scott Kelly’s genetic makeup.

NASA scientists confirmed the preliminary findings of the study earlier this year. They claim that 93 percent of Scott’s genes returned to normal after his return to Earth. The Jan. 31 announcement also stated that the remaining 7 percent of the astronaut’s genes exhibited longer-term changes. These genes were related to his immune system, DNA repair, bone formation networks, and others.

“Mark and Scott Kelly are still identical twins; Scott’s DNA did not fundamentally change. What researchers did observe are changes in gene expression, which is how your body reacts to your environment,” reads an official update from NASA.

The agency compared the change to that exhibited in humans who undergo extreme stress, such as mountain climbing or scuba diving.

Scott Kelly became the first American astronaut to spend 12 consecutive months in space when he completed his 340-day mission on the ISS. He served as a Navy fighter pilot and test pilot before his selection by NASA in 1996.

Image Source: Nasa.gov