In a landmark study, a group of U.S. scientists from Johns Hopkins, Stanford University and other institutions has found no long-lasting, major differences between the epigenomes of astronaut Scott Kelly, who spent a year in space aboard the International Space Station, and his twin brother, Mark, who remained on Earth.
![](https://3c1703fe8d.site.internapcdn.net/newman/csz/news/tmb/2019/astronauthas.jpg)
Source: https://phys.org/news/2019-04-astronaut-lingering-major-epigenetic-differences.html