Astronauts Mark and Scott Kelly Are Still Identical Twins, Despite What You May Have Read. That months-old update appears to have fueled this week’s rash of inaccurate stories; Kelly Humphries, a NASA spokesman, said there were no new developments this week. This change of gene expression is very minimal.”. His identical twin brother, Scott Kelly, is also a retired U.S. Navy Captain and astronaut who served aboard the International Space Station on a yearlong mission. “What researchers did observe are changes in gene expression, which is how your body reacts to your environment. Two hundred and forty miles below, Mr. Kelly’s twin brother, Mark, who also served as an astronaut, carried out identical tests. “Mark and Scott Kelly are still identical twins,” the agency said in a statement. “The last time we posted anything was at the end of January, and it was just confirmation that some results from a year ago had been validated,” he said. Six people died in the attack. Mark Edward Kelly (born February 21, 1964) is an American astronaut, engineer, and former U.S. Navy captain. But even the astronauts themselves were snookered. One of them was an appearance in Yakima, Wash., with his twin brother, and fellow astronaut, Scott Kelly. Mark Kelly for Senate Webstore Administered by Bumperactive.com 5907 Burnet Rd. At 5 p.m., the former astronauts and Navy pilots will either read Mousetronaut , a book Mark Kelly wrote about a mouse going to space, or My Journey to the Stars , Scott Kelly’s memoir for kids. Paid for by Mark Kelly For Senate NASA study: Astronaut’s DNA no longer identical to his identical twin’s after year in space, Scott Kelly Spent a Year in Space and Now His DNA Is Different From His Identical Twin’s, Astronaut’s DNA no longer matches that of his identical twin, NASA finds. Mr. Humphries clarified that no twins are 100 percent identical, and that “over time they tend to become less identical, just like every human being.”. A veteran of four space flights, Kelly commanded the International Space Station (ISS) on Expeditions 26, 45, and 46. Mark has spent more than 50 days in space, and has lived on the International Space Station. The seventh of 10 items in the January update refers to a study, by Chris Mason of Weill Cornell Medicine, on the “genetic, epigenetic, and transcriptional dynamics of each twin.” The update was prepared because some NASA scientists were going to a conference to discuss results, Mr. Humphries said. “Scott’s DNA did not fundamentally change,” the space agency said. That fact seemed to get twisted in popular press coverage. He is the author of multiple books as well as an aerospace executive and consultant, and is the Democratic nominee in the 2020 United States Senate election in Arizona. Twin astronauts Scott and Mark Kelly pose at Johnson Space Center in Houston on Jan. 19, 2015, before Scott Kelly's nearly yearlong stay on the International Space Station.