WHAT HAPPENED: Last March, Scott Kelly, a NASA astronaut, landed back on Earth after calling outer space home for almost a year. Why was he out there for so long? It was the ultimate science experiment, of course! Space scientists wanted to know if space would affect a person’s body and/or mind.
NOW WHAT: In addition to learning that Scott grew taller in outer space, it looks like his DNA changed as well. Blood samples from Scott and his identical twin brother, Mark (also a NASA astronaut, but who stayed on Earth) were collected throughout the experiment. When the samples were studied, scientists discovered that the ends of Scott’s chromosomes were longer than his brother’s.