One Year In Space Changed Astronaut's DNA By 7 Percent, Compared To Twin On Earth

| March 16 , 2018 , 13:11 IST

Spending extensive periods outside of Earth's gravity in outer space has a considerable impact on a person's body, ranging from loss of bone mass to atrophy of muscles and even vision problem, apart from the radiation exposure which can cause future complications. A twin study has now discovered that spending 1 year in space causes considerable changes in an astronaut's genes, altering DNA by nearly 7 percent.

Astronaut Scott Kelly spent an entire year in outer space, spending 340 days in the International Space Station (ISS) in 2017, nearly double the amount of time spent by other astronauts, which generally ranges between 5 to 6 months. Scott 's 1-year sojourn was made in order to examine the effects of spending extended periods of time in outer space, as would be required in a journey to Mars.

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Since Scott has an identical twin brother who remained on Earth, the NASA was able to conduct an in-depth study on specific changes in a person's body by spending extensive time outside Earth's atmosphere.

Using Scott Kelley's identical twin brother Mark Kelley as a control subject on Earth, NASA researchers discovered that most of the biological changes Scott experienced quickly returned to his preflight status. While most took hours or days, only a few persisted after 6 months.  

The researchers also discovered was that Scott's telomeres, which are the end caps of chromosomes that shorten along with age, became significantly longer while in space, but shortened two days after his return to Earth. Overall, 7 percent of his genes witnessed changes, as compared to his twin. The changed genes were connected to his immune system, DNA repair, bone formation networks, hypoxia and hypercapnia.