NASA twins study confirms preliminary findings

(CNN) — NASA says researchers have confirmed the preliminary findings of a twin study examining the effects of long-term space habitation.

The study subjects were astronaut twins Scott and Mark Kelly. Scott spent a year in space while Mark remained on Earth.

Researchers compared what happened to Scott while in space with what happened to Mark.

The results showed that most of Scott’s in-space biological changes returned to pre-flight status rather quickly after he returned to Earth.

In one interesting finding, the end-caps of his chromosomes – which normally shorten with age – actually got longer in space and then shortened again on Earth.

The twin study is seen as a stepping stone to a three-year mission to Mars.