Narrator: This is astronaut Scott Kelly back in 2015 ... and DNA was back on Earth: his identical twin, Mark Kelly. Scott and Mark are the only twin NASA astronauts in history.

For example, researchers found Scott’s telomeres were longer and his levels of DNA methylation were lower in comparison to his twin ... while Mark only experienced minor fluctuations. In both cases, ...

A former fighter pilot and Nasa astronaut who has flown 20 million miles in space is a top contender to become Kamala Harris’s running mate. Mark Kelly ... his identical twin brother, Scott ...

Mark Kelly was listed by betting ... he was in the same class as his identical twin brother, Scott. Before his days at NASA, Kelly was a U.S. Navy pilot. He joined the service in 1986, the same ...

Over the same time period, his identical twin brother, Mark Kelly, a former astronaut and current U.S. senator representing Arizona, remained on Earth. My team and I examined blood samples ...

His research included studying the effects of long-duration spaceflight on the human body, comparing his own body to that of his twin brother, Mark Kelly. Whitson is the American astronaut who has ...